Highest lift cam for a stock motor lt1??????
10-29-2018, 04:55 AM
#21
Originally Posted by Phoenix'97 
Ah, better! Okay, the heads won't flow past .4 but what RPM will this level be reached at with the cam I am looking at? Since this is a problem I felt I would likely run into, would 200cc capable heads help remedy this problem and accommodate .6 at whichever RPM level this will happen?
The reason I am attracted to the "restrictive" long runner TPI intake is for its additional torque production from 2500 to 4500 RPM, well beyond what my short runner stock intake can produce. On top of not being happy with my off idle torque, wanting a little more at 1500 RPM than what I currently receive with the stock cam, I am not happy with how flat my torque is on up to 5000 RPM. I don't wish to high rev my car to tap into those higher torque numbers when I can achieve them at mid-range RPM and using the fluid dynamics of the TPI intake. These are the aspects of my LT1 engine and factory set-up that I wish to have changed. If it requires some "race car land" know-how to make it happen then fine but the suggestions I have been given ever since I started asking about cam modifications to my car have not been true to what I am looking for, stock daily driver dedicated performance.
For the sake of ease and the sake of performing this build on a budget, the cast iron B-body LT1 heads which flow 200cc would be something for me to consider as opposed to spending $1000+ per head on the same aluminum aftermarket heads. Again, this is what I need to figure out before hand and whether or not this camshaft idea is doable.
The reason I am attracted to the "restrictive" long runner TPI intake is for its additional torque production from 2500 to 4500 RPM, well beyond what my short runner stock intake can produce. On top of not being happy with my off idle torque, wanting a little more at 1500 RPM than what I currently receive with the stock cam, I am not happy with how flat my torque is on up to 5000 RPM. I don't wish to high rev my car to tap into those higher torque numbers when I can achieve them at mid-range RPM and using the fluid dynamics of the TPI intake. These are the aspects of my LT1 engine and factory set-up that I wish to have changed. If it requires some "race car land" know-how to make it happen then fine but the suggestions I have been given ever since I started asking about cam modifications to my car have not been true to what I am looking for, stock daily driver dedicated performance.
For the sake of ease and the sake of performing this build on a budget, the cast iron B-body LT1 heads which flow 200cc would be something for me to consider as opposed to spending $1000+ per head on the same aluminum aftermarket heads. Again, this is what I need to figure out before hand and whether or not this camshaft idea is doable.
You're just speaking word salad here. You need to go get an "engines 101" book and start there.
10-29-2018, 05:36 AM
#22
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Originally Posted by sbs
You're just speaking word salad here. You need to go get an "engines 101" book and start there.
I suppose I am going to get all the help I can here...
10-29-2018, 09:00 AM
#23
Originally Posted by Phoenix'97
I can see no one has a real answer to this question posed by both the original poster and myself. How high can you go in cam lift before either your heads or intake are unable to flow what the cam can bring in? I like how the car drives and I like the stock cam, I am sure the original poster felt the same way. However, more lift and more power production from the stock camshaft would make a stock LT1 more enjoyable after 10-years of year-round daily driving with her. .
Super high cam lift numbers means aggressive ramp rates, which means expensive/quality springs and retainers are required. But, you may be limited by the stock spring pad on a OEM head. All you may succeed in doing is beating up a lot of valve train parts for the sake of "proving the internet wrong"
Quick google on stock LT1 head flow. See how its just dead past .4 on the intake side? So yes, you may gain something by tossing the valve open faster via a tall lift, but, thats one aspect to a large puzzle that you are not looking at.
"LIFT: INTAKE: EXHAUST:
.100 59 44
.200 121 98
.300 169 127
.400 200 149
.500 203 160
.550 202 160
.600 ---- ----"
While performance wise, GM engineers are looked down at, for making the most out of a engine for the 90% of people who drive them, GM does great. I think you would be hard pressed to improve upon their work within the small window you are focused on.
Have you talked to a custom cam designer?
10-29-2018, 08:31 PM
#26
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Originally Posted by Shownomercy
You are entering into the world that require specifics, and not just generalized questions.
Super high cam lift numbers means aggressive ramp rates, which means expensive/quality springs and retainers are required. But, you may be limited by the stock spring pad on a OEM head. All you may succeed in doing is beating up a lot of valve train parts for the sake of "proving the internet wrong"
Quick google on stock LT1 head flow. See how its just dead past .4 on the intake side? So yes, you may gain something by tossing the valve open faster via a tall lift, but, thats one aspect to a large puzzle that you are not looking at.
Super high cam lift numbers means aggressive ramp rates, which means expensive/quality springs and retainers are required. But, you may be limited by the stock spring pad on a OEM head. All you may succeed in doing is beating up a lot of valve train parts for the sake of "proving the internet wrong"
Quick google on stock LT1 head flow. See how its just dead past .4 on the intake side? So yes, you may gain something by tossing the valve open faster via a tall lift, but, thats one aspect to a large puzzle that you are not looking at.
Originally Posted by Shownomercy
While performance wise, GM engineers are looked down at, for making the most out of a engine for the 90% of people who drive them, GM does great. I think you would be hard pressed to improve upon their work within the small window you are focused on.
Originally Posted by Shownomercy
Have you talked to a custom cam designer?
Originally Posted by 350 groundpounder
.525 lift seems to be the sweet spot for performance on an untouched stock lt1 head.
One of the reasons GM used .525 lift on the hotcam.
My Lloyd speced cam uses .533 lift on my stock heads with valve job.
One of the reasons GM used .525 lift on the hotcam.
My Lloyd speced cam uses .533 lift on my stock heads with valve job.
10-29-2018, 08:37 PM
#27
No, my point was its easy to make a race car cause you accept that you sacrifice the ability to have it be a car that 90% of the population could drive with out knowing its not factory.
(for the most part)
(for the most part)
10-29-2018, 10:16 PM
#28
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Join Date: Sep 2018
Location: In the mitten
Posts: 29
Stock valve springs will limit lift due to coil bind over .500 lift exact number will vary but needs checked. Aftermarket high lift high pressure along with conical springs will allow for higher lift. The max lift should match airflow, no benefit to have too much lift. Not sure about 1.7 rockers on stock displacement unless you have a special "fast action" cam. IMO they are unnecessary unless you're doing a stroker where internal rotating clearance is a concern. 1.7 also allows for a larger base circle or a camshaft.with less flexing.
10-29-2018, 10:21 PM
#29
LEs sleeper cam would be great for your low-mid range torque. I was after the same type of powerpand. I like low-mid range power 1200-5000rpm.
LE speced me a 215/224 with a 112 lsa.
My car has torque off idle and the mid range 3000-4500rpm is nasty.
i have a m6 trans, 342 gears.
it ran 100mph in the 1/4 stock.
with this tiny cam and bolt ons it runs 107-110mph 1/4's now and drives like stock.
I went with 1 5/8 headers from mac instead of 1 3/4 headers like most usually do, this prob aids in low end torque. This is my daily driver March-October.
Now my Saturday Night Special ride is a 97 SS M6.
LE ported trick flow heads, 383 stroker, ported stock intake, 58mm TB, 1 3/4 headers, to a 4 inch mufflex exhaust, stage 2 spec clutch and a 410 geared 8.8 ford rear end with custom forged axles. This car pushes the torque curve up to around a 4-4500 rpm peak. Whereas the stock headed baby cam car peaks around 3000-3500.
LE speced me a 215/224 with a 112 lsa.
My car has torque off idle and the mid range 3000-4500rpm is nasty.
i have a m6 trans, 342 gears.
it ran 100mph in the 1/4 stock.
with this tiny cam and bolt ons it runs 107-110mph 1/4's now and drives like stock.
I went with 1 5/8 headers from mac instead of 1 3/4 headers like most usually do, this prob aids in low end torque. This is my daily driver March-October.
Now my Saturday Night Special ride is a 97 SS M6.
LE ported trick flow heads, 383 stroker, ported stock intake, 58mm TB, 1 3/4 headers, to a 4 inch mufflex exhaust, stage 2 spec clutch and a 410 geared 8.8 ford rear end with custom forged axles. This car pushes the torque curve up to around a 4-4500 rpm peak. Whereas the stock headed baby cam car peaks around 3000-3500.
Last edited by 350 groundpounder; 10-29-2018 at 10:27 PM.
10-29-2018, 10:49 PM
#30
Without having reads all that's posted here, I will say this...……..stock LT1 heads hit their peak flow right around the .600" mark. Any lift more than that and you'll have airflow turbulence and power production will suffer.
Have a good evening.
KW
Have a good evening.
KW
11-01-2018, 08:56 AM
#31
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Posts: 2,559
LS7 is an emission cam too. That's why the duration is so small. You'd be giving up a ton of power by running a cam with only 200 degrees of duration. LS7 engines pick up a **** ton of power when you swap the stock cam for something big.
11-02-2018, 05:55 AM
#32
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Originally Posted by joelster
LS7 is an emission cam too. That's why the duration is so small. You'd be giving up a ton of power by running a cam with only 200 degrees of duration. LS7 engines pick up a **** ton of power when you swap the stock cam for something big.
Also, I know this is a juggling act, but aside from emissions doesn't a wider lobe separation help to give you better fuel economy? The LS7 is given a good EPA rating for a 7.0L engine and with a 120 lobe separation from a tone-down of power, I can start to see how it is achieved. This is the balance I wish to maintain with my car simply because she is more of a daily driver for me than merely a spring/summer only toy or weekend only car.
11-02-2018, 11:56 AM
#33
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Location: Long Beach, MS
Posts: 400
Originally Posted by Phoenix'97
I may even be content with an aftermarket reproduction of the LT4 cam (not the hot cam) at 115 lobe separation with better lift than the stock LT1 cam.
it gets it's increased lift at the rocker.
11-02-2018, 06:48 PM
#34
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Originally Posted by fbody_brian
The lt4 cam has less lift than the stock cam...
it gets it's increased lift at the rocker.
it gets it's increased lift at the rocker.
I am still thinking a custom grind will be in order but it really is going to be something close to my stock cam or the 1988-1989 L98 cam yet inspired by the LS7 cam with higher lift. Depending on what they come up with and what simulated torque curves provide, perhaps it would be worthwhile to go the full 120 in separation.
11-07-2018, 12:26 AM
#35
Originally Posted by Phoenix'97
…….Also, I know this is a juggling act, but aside from emissions doesn't a wider lobe separation help to give you better fuel economy?.......
You want low RPM grunt? I suggest more gear......just like I always have.
KW
