CAM recommendations
TECH Enthusiast
Joined: May 2008
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From: Carnation, WA
Summit is recommending the 8704 https://www.summitracing.com/parts/sum-8704, however have yet to answer the part-throttle low speed stability.
I will be running tilton manual brakes with a custom pedal assembly..... that keeps me in the neanderthal ranks...... more of a troglodyte...... for this build, a bit of a Luddite, just dont want electric/power/automatic anything in the Fiat build because todays cars have soured me on electrics/electronics/automatics
Just read a comparison article listing Crane cam (.590, 224/232, 114 lsa).
https://www.streetmusclemag.com/tech...ew-327-vs-lm7/
https://ls1tech.com/forums/forced-in...-cam-test.html echos the high RPM gains.
Summit is recommending the 8704 https://www.summitracing.com/parts/sum-8704, however have yet to answer the part-throttle low speed stability.
Just read a comparison article listing Crane cam (.590, 224/232, 114 lsa).
https://www.streetmusclemag.com/tech...ew-327-vs-lm7/
https://ls1tech.com/forums/forced-in...-cam-test.html echos the high RPM gains.
Summit is recommending the 8704 https://www.summitracing.com/parts/sum-8704, however have yet to answer the part-throttle low speed stability.
I think a smaller cam would be better.... 224/224 or 224/228 in an LS1 drove great back in the day.... great all around power... just not a ton of 6500rpm+ power. That in a 5.3 would be "bigger" and maybe just about perfect. I wouldn't run anything in the 230 duration intake lobe spectrum. I had a 233/239 in an LS1 with AFR 205 heads/LS6 intake and headers making 440rwhp in 2004. It drive ok with part throttle in a 2800lb RX-7 and tuning back then wasn't the greatest so it did buck/surge a little on the freeway if you were in a certain RPM range.... but from 4000rpm-7100rpm it was a maniac and did 100mph in the 1/8 and 128mph 1/4.... below 3500rpm it was pretty soft. I never changed it out for 20K street miles and a bunch of road race track days..... but smaller would've been better for sure.
Run as much compression as you can for your octane... I like lightweight flywheels (11lb alum) in my cars.... makes it rev super fast. By the time you put that transmission in your car... you could've just bought a TKX and have a pretty straight forward setup for not much more.
Run as much compression as you can for your octane... I like lightweight flywheels (11lb alum) in my cars.... makes it rev super fast. By the time you put that transmission in your car... you could've just bought a TKX and have a pretty straight forward setup for not much more.
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
a TKX would cost more than all the parts and the car have cost to date.
Thanks for the cam suggestion.
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From: Ohio, Georgia, Nevada, Texas
@Scott Danforth,
I can't speak for whom you spoke with previously at Summit but I wouldn't recommend our 8704 for this application. It would not have favorable driveability in an application like this with it's 17* of overlap. I would go right along with @68Formula's recommendation of our SUM-8715R1. Specs on it are .600/.575, 222/234, 115+3 with -2* overlap. It's widely used for all types of combos. It'll have a smooth to noticeable idle with great manners and make power right up there with "Stage 2" cams. The 8715R1 would be an excellent candidate in an application like this being daily friendly and a joy on an Auto-X course. Pair it with our .600" lift beehives and it'll be happy out to 6,800 plus. As an upgrade we offer the Trickflow by PAC .660" lift duals.
Joe, your fellow LS1Tech member who works the forum for Summit Racing.
I can't speak for whom you spoke with previously at Summit but I wouldn't recommend our 8704 for this application. It would not have favorable driveability in an application like this with it's 17* of overlap. I would go right along with @68Formula's recommendation of our SUM-8715R1. Specs on it are .600/.575, 222/234, 115+3 with -2* overlap. It's widely used for all types of combos. It'll have a smooth to noticeable idle with great manners and make power right up there with "Stage 2" cams. The 8715R1 would be an excellent candidate in an application like this being daily friendly and a joy on an Auto-X course. Pair it with our .600" lift beehives and it'll be happy out to 6,800 plus. As an upgrade we offer the Trickflow by PAC .660" lift duals.
Joe, your fellow LS1Tech member who works the forum for Summit Racing.
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
@Scott Danforth,
and it'll be happy out to 6,800 plus.
Joe, your fellow LS1Tech member who works the forum for Summit Racing.
and it'll be happy out to 6,800 plus.
Joe, your fellow LS1Tech member who works the forum for Summit Racing.
Joe, what do you have that will take it to 7000+ RPM if needed. Im looking for something a bit more street friendly than my 330hp NA V6 was, however that was an 7500 RPM grenade motor that was on the edge of insane.
Im fine with some un-refined manors. just a step or two below Sid Vicious or Keith Moon thrashing a hotel room, however something that just will not buck uncontrollably.
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Joined: Jun 2011
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What heads are you planning to run? As good as the stock LS4 heads are, it's going to take more than that to be capable of over 7k.
And to clarify you're earlier statement on the headers, they're basically going to be like a custom mid-length, correct?
And to clarify you're earlier statement on the headers, they're basically going to be like a custom mid-length, correct?
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I prefer the exact opposite of what many are saying. I'd want a snappy tight lsa and quite a bit of duration at least in the 230's. As you say, at 2200lbs you don't need much down low. I really liked the MS3 cam. You can see in the graphs its not giving up a ton compared ot the stock cam over 3k. It's also made within 10hp of the most i've ever seen on an SBE long block 5.3. (472hp) I ran this setup on my 2400lb (race weight) Model T. It was plenty down low and pulled like an SOB up top. I ran it with twin 78mm turbos... but regardless, the power band was pretty impressive I thought. In my experience if the throttle is jerky then you have a linkage issue or too big of a TB on it with not enough TB cam... Or tune issues. I've yet to have a cam provide "jerky operation".
238/242, .600'/.600', 112 LSA, 110 ICL
https://www.texas-speed.com/p-1152-t...-camshaft.aspx
Why limit yourself on power with a tame cam? You don't need the grunt down low with a feather weight, and you want all the "pull" up top!
238/242, .600'/.600', 112 LSA, 110 ICL
https://www.texas-speed.com/p-1152-t...-camshaft.aspx
Why limit yourself on power with a tame cam? You don't need the grunt down low with a feather weight, and you want all the "pull" up top!
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
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From: Bradentucky Florida
Heads will be 243 / 799 heads with a mild port job.
Headers will be what fits when I am done making them. Shorter than a long-tube, longer than a shorty.
If a stock LM7 can be spun to 7k with a cam change, used springs and ls7 lifters, a stock bottom LS4 with proper valve train should hit it without a problem. Then if/when I blow it up, I can look at a stronger bottom
Headers will be what fits when I am done making them. Shorter than a long-tube, longer than a shorty.
If a stock LM7 can be spun to 7k with a cam change, used springs and ls7 lifters, a stock bottom LS4 with proper valve train should hit it without a problem. Then if/when I blow it up, I can look at a stronger bottom
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
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From: Bradentucky Florida
I prefer the exact opposite of what many are saying. I'd want a snappy tight lsa and quite a bit of duration at least in the 230's. As you say, at 2200lbs you don't need much down low. I really liked the MS3 cam. ......... In my experience if the throttle is jerky then you have a linkage issue or too big of a TB on it with not enough TB cam... Or tune issues. I've yet to have a cam provide "jerky operation".
...........
Why limit yourself on power with a tame cam? You don't need the grunt down low with a feather weight, and you want all the "pull" up top!
...........
Why limit yourself on power with a tame cam? You don't need the grunt down low with a feather weight, and you want all the "pull" up top!
regarding jerky operation. i have had a weird RPM flutter with some cams on some builds (mostly carb builds), which is just made worse when in higher gear, part throttle at steady state cruising. I had a truck I built that you couldnt be in 5th gear at 2000-2500 RPM which I attribute to the "peaky" cam and light weight flywheel with a total weight of 2500#. it could be the throttle linkage issue, however a few of them were worse while cruise was set.
Thanks for the Texas speed MS3 recommendation
10 Second Club
Joined: Aug 2010
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From: Harford Co. Maryland
Maybe call Steve over at CamMotion (member here- Speedtigger) who has a 3700# Buick running 9's last I seen here.
1965 Skylark LQ9 Retrofit / Swap - Build Thread - LS1TECH - Camaro and Firebird Forum Discussion
1965 Skylark LQ9 Retrofit / Swap - Build Thread - LS1TECH - Camaro and Firebird Forum Discussion
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Joined: Jun 2016
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From: Central Cal.
Maybe call Steve over at CamMotion (member here- Speedtigger) who has a 3700# Buick running 9's last I seen here.
1965 Skylark LQ9 Retrofit / Swap - Build Thread - LS1TECH - Camaro and Firebird Forum Discussion
1965 Skylark LQ9 Retrofit / Swap - Build Thread - LS1TECH - Camaro and Firebird Forum Discussion
TECH Resident
Joined: Jun 2011
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So to summarize:
Probably want to run a lower power valve if it's the 6.5" one (although you could try it and see if it dumps in fuel at idle or cruise). A 4.5" or 3.5" will likely be necessary. If you're tuning with a wideband, it'll probably be happiest with a slightly rich mixture at cruise (13.5-14.0). Start the timing around 18* static w/ out vacuum. And consider experimenting with the distributor hooked to manifold as opposed to a ported vacuum source (maybe another 8* hooked straight to vacuum).
- 5.3L 10:1 Compression
- Mild Ported 799/243 heads
- Single plane intake and 830cfm carb with annular boosters
- Headers: Mid-length (ish)
- Unboosted (no turbo, blower, or nitrous)
- 2200lbs+driver
- 3.07 rear with 26.85 tall tires
- AR5 Trans: 3.75 first, 2.26 second, 1.37 third, 1:1 fourth, and . 73 overdrive
- Mostly street use with occasional strip and autocross
- Decent street manners 1500+rpm at part throttle
- Desire to push it up to 7k+
Probably want to run a lower power valve if it's the 6.5" one (although you could try it and see if it dumps in fuel at idle or cruise). A 4.5" or 3.5" will likely be necessary. If you're tuning with a wideband, it'll probably be happiest with a slightly rich mixture at cruise (13.5-14.0). Start the timing around 18* static w/ out vacuum. And consider experimenting with the distributor hooked to manifold as opposed to a ported vacuum source (maybe another 8* hooked straight to vacuum).
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
Yes .... In a nutshell. Timing will be via an MSD 60143. AFR is planned
The 830 carb currently has 4.5 PVs as I had it on the boat for a bit. I also have a toolbox full of PVs, bleeds, jets, etc, not to mention 2 other 4150s
May switch final to 3.54:1 if the 3.07 is too steep once it's on the road
The 830 carb currently has 4.5 PVs as I had it on the boat for a bit. I also have a toolbox full of PVs, bleeds, jets, etc, not to mention 2 other 4150s
May switch final to 3.54:1 if the 3.07 is too steep once it's on the road
In every test I’ve seen, a 706 head (small valve 61cc chamber) picks up over the 243. So why do people run 243’s?
The smart money says sell the 243s for $400+. Buy small chamber heads cheap, and put the porting money in those. The intake valve is lighter weight as well. I routinely run mine to 7800 on a turbo setup with summit lifters and 3/8 push rods (need to hog out the push rod holes a bit) and a BTR dual spring kit. (single spring if better (lighter) if you don’t need the additional valve control with a milder cam). Most “porters” prefer the 706 head as they can shape the smaller ports more towards a race port. You also don’t give up deck thickness for a more race-oriented CC size. You can also cut them to run the bigger 2.02 intake valve pretty cheaply if you prefer.
The smart money says sell the 243s for $400+. Buy small chamber heads cheap, and put the porting money in those. The intake valve is lighter weight as well. I routinely run mine to 7800 on a turbo setup with summit lifters and 3/8 push rods (need to hog out the push rod holes a bit) and a BTR dual spring kit. (single spring if better (lighter) if you don’t need the additional valve control with a milder cam). Most “porters” prefer the 706 head as they can shape the smaller ports more towards a race port. You also don’t give up deck thickness for a more race-oriented CC size. You can also cut them to run the bigger 2.02 intake valve pretty cheaply if you prefer.