Cam suggestions....

[black_ss_blazer]

LQQKING for some suggestions...2001 2 door 2 wheel drive Blazer......2001 4.3 stock bore short block, heads cleaned up a little...bigger valves, automatic, 3.73's

[nomaboy]

i just ordered the bottom one for my truck. summit part # is 1439811. i was told it would work just fine for my app. i have a stock converter and 4.10 gears. so i would think it might work for you. if not definatly the 2nd one from the bottom. talk to obi wan cause he has some very insightfull info about too much lift for the vortech heads.
hope this helps
http://www.cranecams.com/index.php?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=6&Engine_Make=CHEVROLET&Year=2001&Engine_Size=4.3%20L

[nomaboy]

and by the way, that pic in your cardomain with you racing that white mustang, was that a 6 or an 8 cyl. either way i think it is funny seeing any mustang get its ass raped by a s10. nice truck.

[black_ss_blazer]

it was an 8cyl ......I didnt hold him off too long, but I bet got his attention...

[ZR1 S10]

IMO Get a a 260AHR custom grinded to .480 lift from comp!

Theres a ton of people(incl syty guys) running comp cams now with GREAT results! I've noticed the guys on here seem to like crane. But theres so many more running comp cams!

I've got the 270AHR myself but I've got a manual tranny.

[ZR1-S10]

I like comp cams. I'd go with the 266AHR customed for .480 lift, the 270AHR has more Adv. duraton and more duraton at .050 lift but it has more lobe separtion (114* to 112*) then the 266AHR. My sim shows a flatter curve with the 266AHR but still has all the peak of the 270AHR.

[rat]

I like comp cams. I'd go with the 266AHR customed for .480 lift, the 270AHR has more Adv. duraton and more duraton at .050 lift but it has less lobe separtion then the 266AHR.
The 270AHR has 2* more lobe seperation than the 266HR.

The 260AHR has good torque. Mine quits making power at about 5000RPM. If you go with one of the more agressive ones, you will need a stall converter. The 3.73's will help too.

I would have the guides cut down for more lift while you have the heads off for bigger valves.

If you did the bigger valves before, and you don't want to pull the heads, then get the cam ground for no more than .470" of lift. The last truck i did, the exhaust retainer to seal clearence was .480". I have heard that you are suposed to go with at least .060" of clearence here.

EDIT: you will have to pull the heads anyway to machine for the larger valve springs unless you go with the crane one. I was not able to get the 983-12 springs over the stock guides. The id of the springs was .845", and the od of the guide was .850". Comp, and crane sell the tools to do all of the machining yourself.

[ZR1 S10]

The only reason I say 260AHR is because on another forum there was a guy with a stock converter and he had the 266HR and didnt like it. He went to the 260AHR and it was a major upgrade!

I think a 266HR with a mild stall could be a pretty deadly combo for little $$!

[black_ss_blazer]

anybody on here run an automatic with a 270AHR and a bigger converter..????




anyone ever run one with a drifferent lobe seperation.....like a 110*?

[ZR1-S10]

110* is too wild for the ECU. As for the converter ask Sparky, he has a 3200 stall converter.

[black_ss_blazer]

110* is too wild for the ECU. As for the converter ask Sparky, he has a 3200 stall converter.

Why is it to wild...???....What about a re-flash or ls1 edit..?

[ZR1 S10]

My 270AHR is 114* and its pretty wild. I'm not to smart with cams so ya :(

[rat]

Generaly when you tighten the lobe seperation you make the powerband more peaky. It will also give you less vacum at idle, and this is why it would be hard for the computer to keep it running. The 270AHR should be fine if you do gears, and a stall converter. Since the 270AHR starts making power at around 2000rpm you would want a minimum of 2500 rpm stall, and probably higher. You will still need a reflash, to raise the rev limit a bit to take advantage of the new powerband, and to make it shift in the new powerband.

[Maximus]

Boy you sure have a lot of big plans to do black ss blazer lol.It's good to have all the info when you get ready to do it.

[biglouie_underpressure]

i run crane with 112LSA

[black_ss_blazer]

Boy you sure have a lot of big plans to do black ss blazer lol.It's good to have all the info when you get ready to do it.

I want the one of the best running n/a 2nd gen blazers around ....... that's engine looks somewhat stock....
and yes, thanx for all the info EVERYONE..!!!

[Maximus]

I had bought a 266HR Comp cam for the 4.3 engine im building but decided not to use it.I can't remember who it was that told me about them but GM performance sells some great cams for the 4.3.After they recommended it I looked up the specs and decided to return my Comp Cam and buy the GMP cam part number 10134321.I really like the cam profile and lift for what im gonna be using my truck for.I have not installed it yet in fact it's still in the damn box.But I convinced a local guy with a 90 TBI 5 speed to install it and it really made a big difference in his.It has real nice low to mid range power but starts topping out around 5000rpm.With the stock programming it run fine with no problems but after he installed a Superchips ecm chip it run a lot better.It's for non balance shaft engine but you could get a custom grind cam just like it.Anyway just thought I would give you another option to look at.If I ever get that damn engine installed im gonna post up results for the TBI 4.3 auto guys.

[Hammer]

I was under the impression that crower was the route to go, this apparently is not the case?

[rat]

I was under the impression that crower was the route to go, this apparently is not the case?
I was not aware that crowler made a cam for the ballance shaft motors, i thought they made them only for the non ballance shaft engines.

[Maximus]

I don't think Crower's is a roller cam either.

[Hammer]

page 22 roller cam shafts,

part #03450, #03451, #03452
http://www.crower.com/misc/m_cat.shtml

fyi, i got that info directly from Obi Wan. you can also get custom grind. those cams have less lift and longer duration which is what our intake setup benefits from, duration.

[Sparky2263]

I'm pretty sure (99.9%) those cams are for non-balance shaft motors.

I was going to go the re-grind my stock cam route. Wasn't worth it. Roller 1.6 rockers did about as much as what they could give me.

[Sparky2263]

i just ordered the bottom one for my truck. summit part # is 1439811. i was told it would work just fine for my app. i have a stock converter and 4.10 gears. so i would think it might work for you. if not definatly the 2nd one from the bottom. talk to obi wan cause he has some very insightfull info about too much lift for the vortech heads.
hope this helps
http://www.cranecams.com/index.php?show=browseParts&lvl=2&prt=5&Vehicle_Type=Auto&Cylinders=6&Engine_Make=CHEVROLET&Year=2001&Engine_Size=4.3%20L


That's smaller than my stock CPI cam.

I have an extra if anyone's interested.

[nomaboy]

what is smaller? the lift?

[Sparky2263]

Lift is smaller and duration is practically the same. That cam would be a good upgrade for a TBI motor. Not worth it, IMO, for a CPI motor.

[nomaboy]

the other cams had too much lift for my engine and were way out of my rpm range

[ZR1 S10]

Like I said a custom grind 260 or 266 is the way to go. Just give comp a call or email:

www.compcams.com

[ZR1-S10]

Those roller cams from Crower are way too wild, woun't work with the ECU and I'm not sure about the balance shaft. I agree with the other ZR1: call Comp Cams and get a custom grind 260 or 266.

[94s10]

That's smaller than my stock CPI cam.

I have an extra if anyone's interested.

just curious as to how much you would want for that CPI cam? i can pick it up too.

[nomaboy]

well. the adv. duration is the same on the comp as on my crane. in fact, the duration is longer on the exhaust side of my crane than the comp. i will just put 1.6 rockers in to make up for the lift of the crane. the 1.6 rockers will take me to about .458 of lift which is close to the max lift my head can take before needing machined. i dont want to have to machine anything.

[Sparky2263]

just curious as to how much you would want for that CPI cam? i can pick it up too.

$30 sound good?

[94s10]

do you know the specs of the cam?

[Sparky2263]

It's a stock 93 CPI cam. Much better than a TBI cam.

[94s10]

yeah but if its not much better than i will save for something else.

[Sparky2263]

Tell ya' what. Go to the track and make 3 passes. Post your time slips. I'll give you the cam. Stick it in and do the 3 pass deal again.

My contribution so we all learn something.

I got $20 says you pick up .35 or more.

[Maximus]

Very substantial difference between a TBI and a CPI cam.So you will notice the difference.Look at the cam profile for both and you will see how much different they are.

[94s10]

hmmm want to help me instal it and i will still give you 30$??

[Sparky2263]

hehe, lemme think on that one.

Maybe a before and after here at Gainesville Raceway?

[94s10]

sounds good to me. i will have the blower on by then so i will be wanting to test it at the track. i've never installed a cam before so i would be a little nervous to tackle it myself having no experience. plus i have no tools in orlando, they are all back home in englewood

how long do you think it would take? i wonder if it will work with me ECU...

[Sparky2263]

ugh! Put the cam in before the blower, puhleeze!

Seriously though, much easier install w/o the blower and a better test.

How long for a cam change? 3-5 hours on avg.

[94s10]

i will put off installing the supercharger then, i'm in no hurry. but i dont know how long i can take that thing sitting in my house looking back at me and screamin "instal me" lol. i guess i could always just disconnect the charge pipe to run NA for a few passes, then put it back on to see how the boost goes, kill 2 birds with 1 stone.

[94s10]

i may be going to the track here in bithlo to make some before passes. trying to find the time, its finals week and they are beating me like a red headed step child...

[Hammer]

i didn't see any contest to the crower applications, or did i miss something? gmperformance has a good cams also.

then again i guess you aren't dealing with the sfi, you are dealing with tbi and cpi

[ZR1 S10]

I beleive the gm ones are solild or flat tappet cams not roller.

[Sparky2263]

GM doesn't make performance cams for the balance shaft motors. Dammit!

[Maximus]

I beleive the gm ones are solild or flat tappet cams not roller.No they have roller cams too.Here is their 90' V6 cams straight from the GMPP sight.
6269733 Hydraulic Flat Tappet
This hydraulic flat tappet is a marine cam for 229ci V6 with 108-132 degree semi-even fire crankshaft. It's a good street performance cam. The duration at lash point in degrees (intake/exhaust) is 294/306; duration at .050" tappet lift (intake/exhaust) is 202/210; and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 410/410. Lobe centerline is 113 degrees.
http://www.gmgoodwrench.com/perfparts/images/spacer.gif
10051147 Hydraulic Roller Tappet
This hydraulic roller tappet is a V6, 90 degree version of L-79 small-block V8 cam for 4.3L even-fire engines. Use only with roller tappet block on engines without balance shift. The duration at lash point in degrees (intake/exhaust) is 318/318; duration at .050" tappet lift (intake/exhaust) is 222/222; and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 447/447. Lobe centerline is 114 degrees.
http://www.gmgoodwrench.com/perfparts/images/spacer.gif
10051165 Hydraulic Flat Tappet
This hydraulic flat tappet is a V6, 90 degree version of L-79 small-block V8 cam for 4.3L even-fire engines. It has excellent power and torque, and is for engines without balance shift. The duration at lash point in degrees (intake/exhaust) is 320/320; duration at .050" tappet lift (intake/exhaust) is 222/222; and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 447/447. Lobe centerline is 114 degrees.
http://www.gmgoodwrench.com/perfparts/images/spacer.gif
10134321 Hydraulic Roller Tappet
This hydraulic roller tappet is a high performance street and marine cam for 4.3L even-fire engines. Use only with roller tappet block on engines without balance shift. The duration at lash point in degrees (intake/exhaust) is 321/316; duration at .050" tappet lift (intake/exhaust) is 224/224; and maximum lift with 1.5:1 rocker ratio (intake/exhaust) is 450/460. Lobe centerline is 112 degrees.

[lamerboy]

For anyone looking into doing a comp cam swap heres some links.

Comp (http://www.compcams.com/Technical/CurrentCatalog/HTML/124-127.asp) 260 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D440%2D8&N=0&part=CCA%2D56%2D440%2D8&autoview=sku&Ntk=KeywordSearch), 266 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D450%2D8&N=0&part=CCA%2D56%2D450%2D8&autoview=sku&Ntk=KeywordSearch) or 270 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D460%2D8&N=0&part=CCA%2D56%2D460%2D8&autoview=sku&Ntk=KeywordSearch)ahr - Around $250. + New lifters (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=875%2D12&N=0&part=CCA%2D875%2D12&autoview=sku&Ntk=KeywordSearch), Pro Magnum rockers (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=1317%2D12&N=0&part=CCA%2D1317%2D12&autoview=sku&Ntk=KeywordSearch), pushrods (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=7808%2D12&N=0&part=CCA%2D7808%2D12&autoview=sku&Ntk=KeywordSearch), locks (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=611%2D12&N=0&part=CCA%2D611%2D12&autoview=sku&Ntk=KeywordSearch), retainers (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=740%2D12&N=0&part=CCA%2D740%2D12&autoview=sku&Ntk=KeywordSearch), seals (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=503%2D12&N=0&part=CCA%2D503%2D12&autoview=sku&Ntk=KeywordSearch), springs (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=986%2D12&N=0&part=CCA%2D986%2D12&autoview=sku&Ntk=KeywordSearch), timing cover, and timing set (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=3202&N=0&part=CCA%2D3202&autoview=sku&Ntk=KeywordSearch) is about $900 from Summit.

Thats about $1200 just for the cam stuff to do it right. Then while your at it you might as well get the heads ported.

IMO to do the cam swap right you have to pull the engine so you can lower the pan and replace the timing cover properly without leaking.

I've already have a cam and heads, conversion studs, springs, stage II porting, stainless valves, its the rest of the crap I have to buy thats been holding me back from doing the swap..

Dont forget about valve cover clearance to the rockers. Cyipher over on s10forum had his stock valve covers machined to clear the rockers rather than running spacers. ;)

[LEADFOOT]

Question, when the specs for a cam say minimum and max rpm, for instance 1,500 min and 5,000 max. Does that mean my motor has to idle at 1,500 rpm? Or is that when it starts to make power, and the max when the power curve starts to fall out?

[Maximus]

Thats the cams "optimum power ban" to keep it simple.Thats the RPM range the cam is designed to perform the best in.

[LEADFOOT]

Ok, thats what I thought but wasn't sure. Thanx

[LEADFOOT]

In the tech section of my new summit catalog a guy asked what cam and converter combo (and a few other things) could he run on his 1994 blazer with 4.3L V6. Summit replied saying this is the best combo and it will work with your computer. Comp cam (http://store.summitracing.com/default.asp?Ntt=cca-56-450-8&Ntk=KeywordSearch&DDS=1&searchinresults=false&N=0&target=egnsearch.asp&x=44&y=12)tci converter (http://store.summitracing.com/default.asp?Ntt=tci-242700&Ntk=KeywordSearch&DDS=1&searchinresults=false&N=0&target=egnsearch.asp) I'm going to call summit to see if it will work on my blazer too.

[LEADFOOT]

page 22 roller cam shafts,

part #03450, #03451, #03452
http://www.crower.com/misc/m_cat.shtml

fyi, i got that info directly from Obi Wan. you can also get custom grind. those cams have less lift and longer duration which is what our intake setup benefits from, duration.
But what about the afi intake. What if I get that then what cam will be the best. The afi intake has to be alot better than the sorry ass intake gm put on the cpi motors.

[Hammer]

For anyone looking into doing a comp cam swap heres some links.

Comp (http://www.compcams.com/Technical/CurrentCatalog/HTML/124-127.asp) 260 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D440%2D8&N=0&part=CCA%2D56%2D440%2D8&autoview=sku&Ntk=KeywordSearch), 266 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D450%2D8&N=0&part=CCA%2D56%2D450%2D8&autoview=sku&Ntk=KeywordSearch) or 270 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D460%2D8&N=0&part=CCA%2D56%2D460%2D8&autoview=sku&Ntk=KeywordSearch)ahr - Around $250. + New lifters (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=875%2D12&N=0&part=CCA%2D875%2D12&autoview=sku&Ntk=KeywordSearch), Pro Magnum rockers (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=1317%2D12&N=0&part=CCA%2D1317%2D12&autoview=sku&Ntk=KeywordSearch), pushrods (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=7808%2D12&N=0&part=CCA%2D7808%2D12&autoview=sku&Ntk=KeywordSearch), locks (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=611%2D12&N=0&part=CCA%2D611%2D12&autoview=sku&Ntk=KeywordSearch), retainers (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=740%2D12&N=0&part=CCA%2D740%2D12&autoview=sku&Ntk=KeywordSearch), seals (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=503%2D12&N=0&part=CCA%2D503%2D12&autoview=sku&Ntk=KeywordSearch), springs (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=986%2D12&N=0&part=CCA%2D986%2D12&autoview=sku&Ntk=KeywordSearch), timing cover, and timing set (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=3202&N=0&part=CCA%2D3202&autoview=sku&Ntk=KeywordSearch) is about $900 from Summit.

Thats about $1200 just for the cam stuff to do it right. Then while your at it you might as well get the heads ported.

IMO to do the cam swap right you have to pull the engine so you can lower the pan and replace the timing cover properly without leaking.

I've already have a cam and heads, conversion studs, springs, stage II porting, stainless valves, its the rest of the crap I have to buy thats been holding me back from doing the swap..

Dont forget about valve cover clearance to the rockers. Cyipher over on s10forum had his stock valve covers machined to clear the rockers rather than running spacers. ;)

doing work to the votec heads, unless you know specifically what to do, is usually more detrimental then helpful. polishing isn't even neccessary. the main area of cleanup is usually port matching to the exhaust and intake. the intake is the limiting factor, not the heads.

[Hammer]

But what about the afi intake. What if I get that then what cam will be the best. The afi intake has to be alot better than the sorry ass intake gm put on the cpi motors.

if you get that intake then the flow issue should be resolved, however lift is bad for ecm's unless you can reflash because of fluctuation of vacuum it will not like that.

my opinion is still duration over lift.

[rat]

if you get that intake then the flow issue should be resolved, however lift is bad for ecm's unless you can reflash because of fluctuation of vacuum it will not like that.

my opinion is still duration over lift.

I don't think lift has much to do with it, it is the lsa that helps keep the computer happy. Mine runs just fine with .5" of lift.

[Hammer]

whatever it takes to keep the vacuum from severely fluctuating right.

[ZR1-S10]

How can lift be bad for the ECU? The LS7 runs just fine with .591" and thats alot. Also the Vortec heads keep flowing to .600" Lift is usely a win/win combo. I'm not saying we don't need more duration but any of comp cams will run great. They have just the right amount of duration and lots of lift for plenty of power and the 112* LSA and a fast ramp rate to keep the ECU happy. Also note the 266AHR (the one Leadfoot showed us at Summit) starts making power at 1800rpms right at the stock stall speed and keeps going to 5000rpms. Just make sure to machine the the heads for the extra lift and go with some better springs and your be fine.

[Sparky2263]

Headflow on the Vortec head is practically the same from .500 up to .600 lift. There's a thread in here somewhere with a link to the cylinder head flow comparison.

[ZR1-S10]

I've seen the chart, sure it's only +4cfm intake/+3cfm exhaust but evey little bit helps. I don't recommend going over .525" with the cam thats as much as the lifters can go (any more and there out of the bores), you can add 1.6 ratio rockers to get to .560" but I don't know about piston clearence.

[ZR1 S10]

For anyone looking into doing a comp cam swap heres some links.

Comp (http://www.compcams.com/Technical/CurrentCatalog/HTML/124-127.asp) 260 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D440%2D8&N=0&part=CCA%2D56%2D440%2D8&autoview=sku&Ntk=KeywordSearch), 266 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D450%2D8&N=0&part=CCA%2D56%2D450%2D8&autoview=sku&Ntk=KeywordSearch) or 270 (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=56%2D460%2D8&N=0&part=CCA%2D56%2D460%2D8&autoview=sku&Ntk=KeywordSearch)ahr - Around $250. + New lifters (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=875%2D12&N=0&part=CCA%2D875%2D12&autoview=sku&Ntk=KeywordSearch), Pro Magnum rockers (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=1317%2D12&N=0&part=CCA%2D1317%2D12&autoview=sku&Ntk=KeywordSearch), pushrods (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=7808%2D12&N=0&part=CCA%2D7808%2D12&autoview=sku&Ntk=KeywordSearch), locks (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=611%2D12&N=0&part=CCA%2D611%2D12&autoview=sku&Ntk=KeywordSearch), retainers (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=740%2D12&N=0&part=CCA%2D740%2D12&autoview=sku&Ntk=KeywordSearch), seals (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=503%2D12&N=0&part=CCA%2D503%2D12&autoview=sku&Ntk=KeywordSearch), springs (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=986%2D12&N=0&part=CCA%2D986%2D12&autoview=sku&Ntk=KeywordSearch), timing cover, and timing set (http://store.summitracing.com/default.asp?target=partdetail.asp&Ntt=3202&N=0&part=CCA%2D3202&autoview=sku&Ntk=KeywordSearch) is about $900 from Summit.

Thats about $1200 just for the cam stuff to do it right. Then while your at it you might as well get the heads ported.

IMO to do the cam swap right you have to pull the engine so you can lower the pan and replace the timing cover properly without leaking.

I've already have a cam and heads, conversion studs, springs, stage II porting, stainless valves, its the rest of the crap I have to buy thats been holding me back from doing the swap..

Dont forget about valve cover clearance to the rockers. Cyipher over on s10forum had his stock valve covers machined to clear the rockers rather than running spacers. ;)

I disagree.....If you're smart and creative you can get the timing cover on without it leaking. By no means do you have to pull the engine. Nor do you need all those parts (except the springs and retainers). Hope you get it done in this decade. :sleep_125

Although I've got all those parts and did the swap with the worked heads but I didnt pull the motor or drop the pan. :p

[03 Rado]

Headflow on the Vortec head is practically the same from .500 up to .600 lift. There's a thread in here somewhere with a link to the cylinder head flow comparison.

Why does no one listen, Frosty is 100% right. But actually beginning at .450 lift you wont see flow numbers increase at a decent enough percentage of increase to justify costs of having to work the heads to do so. That wasnt added into Lamers $1200 Scheme costs. So for $1200, add the machining, what do you gain over a cam which stay unders .450 lift and just needs springs?? Now I can say NEGLIGIBLE. Vortec heads are better left 100% alone on the intake side and bowl enlargment with valves at 1.65 or so at best on the exhaust side!
Cranes powermax cam and springs if you should so think you have to have them, would yield about the same results as the $1200+ job!

[rat]

Why does no one listen, Frosty is 100% right. But actually beginning at .450 lift you wont see flow numbers increase at a decent enough percentage of increase to justify costs of having to work the heads to do so. That wasnt added into Lamers $1200 Scheme costs. So for $1200, add the machining, what do you gain over a cam which stay unders .450 lift and just needs springs?? Now I can say NEGLIGIBLE. Vortec heads are better left 100% alone on the intake side and bowl enlargment with valves at 1.65 or so at best on the exhaust side!
Cranes powermax cam and springs if you should so think you have to have them, would yield about the same results as the $1200+ job!
What costs $1200? It only cost me ~$70 to machine my heads in my garage. It costs another 50 for the tools to machine for the larger valve springs. Then a couple of head gaskets, and exhaust gaskets, and you are all set for as much lift, and whatever springs you want.

[03 Rado]

What costs $1200? It only cost me ~$70 to machine my heads in my garage. It costs another 50 for the tools to machine for the larger valve springs. Then a couple of head gaskets, and exhaust gaskets, and you are all set for as much lift, and whatever springs you want.

It was the total of Lamers list of parts needed which didnt cover the machine work!

[ZR1-S10]

Well I belive in having a comptle system, if it cost a little more for the machining soo be it. I'd go ahead and port the exhuast side of the head and machine it for more lift and larger springs and a stud conv. Then go add in the $1200 package. As for the extra lift my sims shows a 5hp(mild setup) to 15hp (wild setup) incresse with .560" over .450"

[03 Rado]

I'm not against if your gonna do it, then not go all the way. I stop well before that as to recommend that whole shabang pretty much. If your gonna pretty much track the vehicle, thats one thing, but for a mainly street driver its pretty much a complete waste of money.
Many Magazines and high dollar technical operations have found the Vortec head for the most part is unimprovable to justify the dollars going into it. They flow as well if not better than most lower cost aftermarket heads. For a 6 cylinder they will support just over 300 h.p. without blinking. By that point, disgarding your intake, your running, the intakes would have puked well before then. Forced air motors just like to see the exhaust side opened up, they dont need the intake side done.They've also found if you are going to attempt the intake side, its only one little area that works well to attempt, but even then 15 CFM is about all you'll see. Theyve tested going to the 2.02 valves and saw very little to justify doing do and some have found it disturbs the air flow during certain load levels. GM did there homework farily well this this circle track based head arrangment and its been stated more often than not, dont screw with them if youve exceeded there design useability, buy new heads all together to do what you need!

[ZR1-S10]

Oh I'm going all out! Like my twin I'm aiming for 500hp thanks to full stage 3 heads, full comp cams package, and 2114 conv, only differnce is he's going with a turbo and I'm using a Wynjammer.

[Sparky2263]

my sims shows a 5hp(mild setup) to 15hp (wild setup) incresse with .560" over .450"

Simulator? Simulators are a tool. Used improperly, as any tool,it will not give desired results. Due to the runner size and shape, material thickness and design, lifts over .500 are practically useless. Been there, done that.Many times. And I don't drive a simulator down the track. These heads are excellent heads up to 5500-6000 rpm range. I have seen them pushed to 6500 with no better (and often worse) results than keeping it below 6000. Friend of mine spent countless hours (and quite a bit of JB weld) trying to emulate a port shape and size that SHOULD have been conducive to a 6500 rpm engine. Nada. Power started falling at 6100 and was useless before 6500. This person races NHRA stock. They squeeze every last ounce of power possible from an engine.That engine did propel a J/SA Camaro to an 11.90 1/4 mile though. But a 30k engine is not practical for most of us and if we did have 30k to spend on an engine we'd be running 7 sec 1/4 times.

So, what is practical? What most of us here know from actual experience. Anything over .500" lift is not. Too much work without the results to show for it. My stock cam (cpi) with 1.6 rollers makes a ton of power up to 5300 or so. Knowing the heads are gonna fall off before 5500 for most of us, how much do you need?

B

[ZR1-S10]

Well given the 2114's dual plane setup and the 266AHR cam I'm going with I don't plan on going above the factory 5600rpm cutoff. Your right about the port shape and I'm going to keep it streetable, but the incresse with the lift is mostly still in a useable RPM range.

As for the sim, I know how to use it and it's ben "bang on" step per step with the dyno.

[biglouie_underpressure]

has anyone seen the new vortec heads that flow well past .500?

[ZR1 S10]

Simulator? Simulators are a tool. Used improperly, as any tool,it will not give desired results. Due to the runner size and shape, material thickness and design, lifts over .500 are practically useless. Been there, done that.Many times. And I don't drive a simulator down the track. These heads are excellent heads up to 5500-6000 rpm range. I have seen them pushed to 6500 with no better (and often worse) results than keeping it below 6000. Friend of mine spent countless hours (and quite a bit of JB weld) trying to emulate a port shape and size that SHOULD have been conducive to a 6500 rpm engine. Nada. Power started falling at 6100 and was useless before 6500. This person races NHRA stock. They squeeze every last ounce of power possible from an engine.That engine did propel a J/SA Camaro to an 11.90 1/4 mile though. But a 30k engine is not practical for most of us and if we did have 30k to spend on an engine we'd be running 7 sec 1/4 times.

So, what is practical? What most of us here know from actual experience. Anything over .500" lift is not. Too much work without the results to show for it. My stock cam (cpi) with 1.6 rollers makes a ton of power up to 5300 or so. Knowing the heads are gonna fall off before 5500 for most of us, how much do you need?

B

We can talk about "our friends who race nhra and build 5sec dragsters" or we can go with pure hard facts. Theres ALOT of people running comp cams with .500+ and some with .480 lift with AWSOME results. Beleive what you want but I have the 270AHR .500/.510 and its AWSOME!! Straight power to 5,500 EVEN with our crappy intake!!!! :eek:

[biglouie_underpressure]

We can talk about "our friends who race nhra and build 5sec dragsters" or we can go with pure hard facts. Theres ALOT of people running comp cams with .500+ and some with .480 lift with AWSOME results. Beleive what you want but I have the 270AHR .500/.510 and its AWSOME!! Straight power to 5,500 EVEN with our crappy intake!!!! :eek:
have you seen a flow sheet on those heads stock vs. ported?

[Sparky2263]

We can talk about "our friends who race nhra and build 5sec dragsters" or we can go with pure hard facts. Theres ALOT of people running comp cams with .500+ and some with .480 lift with AWSOME results. Beleive what you want but I have the 270AHR .500/.510 and its AWSOME!! Straight power to 5,500 EVEN with our crappy intake!!!! :eek:

I race NHRA. I didn't address 5 sec. dragsters. I did address stock racers in relation to the countless hours put into Vortec heads and the results acheived. And also related that a 30k motor would put us (S-series) into the 7's.

Here's my point (again), Vortec heads, in stock form, are great heads. Good flow characteristics, nice quench factor and cheap. But you ain't gonna crank over 6500 with them and most of what's past 6000 ain't much. You stated yourself your cam selection as a .500 lift cam. Excellent selection in my view. Wouldn't mind having one in my cpi. With my stock cam and 1.6 rollers, I also pull to 5500. In other words, lift takes a back seat to duration when it comes to these motors.

It has been found (and proven) that enlarging the exhaust valve to 1.6 greatly assists extending the rpm range. It has also been shown that increasing the intake to 2.02 shrouds more of the valve resulting in poor wet flow characteristics. Is it worth putting in the 1.6 exhaust valve then? Dunno. Seems like you gain 'bout 2-300 rpms doing it but need the cam to go with it.

[Hammer]

are the stage 3 heads better than the vortec heads? don't the vortecs flow over 400cfm?

what kind of flow numbers have you seen for those stage III heads vs, never mind louie already asked, lol.

i've also been under the knowledge that bigger valves aren't neccessarily better. what kind of valve springs are you running to achieve 6000+ rpms, and what have you done to the crank, rods, pistons, etc to reduce weight and balance? i don't see the advantage of running above the 4000 mark it you can develop the torque at or below 4000-5000, just an opinion.

[ZR1-S10]

The stage 3 heads are Vortecs, they just have ben fully ported, valves, springs, and stud convertion. The springs will be comp cams 986-12 wicth is a major inprovment to the whimpy 80 pound stock springs. I want a billit forged crank with a 3.75" stroke but unlike the other ZR1 I want to keep it even-fire. Also go with forged pistons but I havn't picked a compresson ratio yet.

[03 Rado]

Are these the same Stage 3 heads that a shop called Machine Performance sells?

This shop was one of the many whom said toying with Vortec heads didnt yield and decent gain when porting was done and showed flow sheets to prove it, but later found out people still wanted this and offered the service to make money, then pushed it afterwards these great gains. The same shop which used a desktop dyno, MAF area size to MAF readings, then recalculated air flows numbers to show some of there other work exceeded over 350 rwhp. The same shop had many low 13 runs and a few 12 second runs which was later found out to be a farce, people were lying for him.
Now as fast as people flocked to him, they are now leaving because there valvetrains have come apart, motors he built blew up or just wouldnt stay running along with a host of other things he did to people.

Stage 1- You screwed me once, shame on you
Stage 2- You screwed me twice, shame on me
Stage 3- You just love to be analized

[Maximus]

Yeah there is a guy on LS2.com who has a 1995 SS S10 as his daily driver who bought a set of those stage III heads and dynoed the engine after the install and said he gained a a little horsepower but lost a good amount of torque.I think he asked for a refund but didn't get it and is thinking of suing.He could be just a unhappy customer who expected to much or something,but he has one VERY fast 1989 IROC with a LS1 and a 6 speed conversion done.So I assume he either knows what he's doing or uses someone who does.He is using a set of highly worked over Pontiac 90 degree aluminum heads now.That's about I all I know about the stage III heads myself.I have never used or seen a vehicle with them.

[ZR1-S10]

No there not from Machine Performance, the other ZR1 got his from Mach Performance I havn't got mine yet (saving up for Wynjammer). When it comes to the heads I'm going to look around and be very picky. RPM sell a set but I'm not sure if there modifed for the Syclone manifold or not (if they are I'll call and see if I can get them without that mod).

[bigplans10]

i was looking at the comp cams and the online cat said the cams are for 80-97 motors will they work in my 99?

[rat]

You need a cam that will work in a '92 up ballance shaft engine.

[bigplans10]

who makes one? i can't find any apps that say they work with my truck

[ZR1 S10]

i was looking at the comp cams and the online cat said the cams are for 80-97 motors will they work in my 99?

As long as you get the ones that say they are for "Balance shaft and computer controlled".

[Dennis S]

Some of you've seen this before but I just saw this thread.......
2001 Crew Cab 4x4, 4.3L, 3.42 gears, Auto tranny, stock tires, daily driver in the city, occasional camper towing, looking for mpg increase, need to pass emissions, not looking at racing but I wouldn't mind turning a few heads on the green light. ;) There's also that PT Cruiser a few weeks ago that hung with me off the green light that's not sitting well with my pride. :rolleyes: I know he's only pulling about half the weight as the CC... but still!!!
It's been suggested to me (not in this forum) that a cam would be the most beneficial investment rather than other mods such as exhaust, computer, etc.
Is a cam swap going to mess with the emissions?
Besides lifters, (I'm guessing I have hydraulic rollers??) what other parts should I be pricing with a cam swap...how expensive could this path get? :banghead_ (http://www.s10planet.com/forum/misc.php?do=getsmilies&wysiwyg=1&forumid=0#)
I can't afford to let the truck sit for more than a weekend and I've got buddies with more knowledge than I who would help.

[rat]

You also need springs, retainers, and locks, new timing set. Lifters aren't necissary unless you have high miles. Also, more than .480" of lift requires some work to get around the retainer to seal clearence lift wise.

My cam swap cost me around $800 for the parts.

[Sparky2263]

The first mods you want to make are breathing mods. Intake and exhaust. Any cam change that would allow better breathing would be hampered by a stock intake and exhaust.

[Dennis S]

You also need springs, retainers, and locks, new timing set. Lifters aren't necissary unless you have high miles. Also, more than .480" of lift requires some work to get around the retainer to seal clearence lift wise.

My cam swap cost me around $800 for the parts.

I was kinda thinking those would need to be replaced. I didn't think it would cost that much though

[Dennis S]

Any cam change that would allow better breathing would be hampered by a stock intake and exhaust.

That's what I was thinking but the other guy was insistent on a cam swap. I just priced a Magnaflow muffler install today. I've already cut off the left front corner of the airbox when I got the K&N filter. I've also ground off about half of the throttle plate deflector. I'll run it for a couple weeks and see where I'm at.

Thanks for the input

[rat]

I was kinda thinking those would need to be replaced. I didn't think it would cost that much though
Cam-300
timing set-50-100
springs-60
retainers-30something?
locks-20 something

And for mine i bought the tools to machine the guides-120

Gaskets, for mine i needed
head gaskets
head bolt set
lower intake manifold
exhaust manifold gasket
maybe a couple more i forgot

[j894]

notice anything worthwild from cutting up the airbox, other than noise?

I did it on my older blazer & dont remember much of any diference.

[Dennis S]

I did the throttle plate and the airbox mods at the same time. I don't know which one caused it but yes, I did notice a substantial increase in noise at the intake. Especially closer to WOT. Seems to have a little more oomph to it.

Don't have enough experience to tell if it's just intake noise or if it might be caused from exhaust restriction. Also, it seems to loose power when the noise picks up (sounds contradictory, doesn't it?). If I back off on the throttle a bit, it picks up again. The muffler next week should eliminate exhaust concerns. If if doesn't improve, I need to get a scanner or something that will check A/F mixture. I want to make sure that it isn't running lean and then figure out how to fix that if it is.

[Sparky2263]

Sounds like either a restricted exhaust or a weak fuel pump. If it was restricted exhaust, the O2 sensor would stay rich at full throttle. If it was a weak fuel pump, it would go lean.

Easy check with a voltmeter.