CAM recommendations
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
CAM recommendations looking at a cam for my next project. engine is an LS4 longblock, running a carb and sitting in a Fiat 500C Topolino Belvedere wagon with an AR5 running a dual disc clutch and C4 suspension with 3.07:1 and a 26.85" rear wheel
Target weight is 2200# (1100kg) without driver
car may see an auto-X course or a drag strip, however will be driven nearly every week when weather allows (face it, its not rain friendly). it will be used for trips and errands.
looking at the following 3 cams. Comp XR275HR, Comp XR281HR, and BTR Hotrod cam
looking for decent street manors above 1500 RPM (no bucking, etc)
COMP 275 222/224 .566/.568 112
COMP 281 228/230 .571/.573 112
BTR HR 217/241 .619/.617 114 +3
what do you recommend and why. trad mag dyno results only tell part of the story. looking for real world 5.3/manual/ultra-light vehicle responses.
Target weight is 2200# (1100kg) without driver
car may see an auto-X course or a drag strip, however will be driven nearly every week when weather allows (face it, its not rain friendly). it will be used for trips and errands.
looking at the following 3 cams. Comp XR275HR, Comp XR281HR, and BTR Hotrod cam
looking for decent street manors above 1500 RPM (no bucking, etc)
COMP 275 222/224 .566/.568 112
COMP 281 228/230 .571/.573 112
BTR HR 217/241 .619/.617 114 +3
what do you recommend and why. trad mag dyno results only tell part of the story. looking for real world 5.3/manual/ultra-light vehicle responses.
the smaller the cam, the more torque down low it is going to make. The smaller cam is also going to drive better and have better street manners. I would vote the 222/224 for these reasons.
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
Appreciate the reply
The car is so light that first and second gear will be nearly useless. Not needing torque down low.
Originally thought of an LNF, however for the same physical space, I can have 2.5x the power and V8 rumble
I'm concerned about cam stability at light throttle/light load to not have drive-line rubberbanding
The car is so light that first and second gear will be nearly useless. Not needing torque down low.
Originally thought of an LNF, however for the same physical space, I can have 2.5x the power and V8 rumble
I'm concerned about cam stability at light throttle/light load to not have drive-line rubberbanding
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
Single plane, HP830 annular. (Although I have a plethora of carbs between 715 cfm and 950 cfm)
Headers will be between a shorty and long-tube as they will be custom to fit. Dumping into 2-1/2" dual exhaust with an X- over. Mufflers when needed.
Headers will be between a shorty and long-tube as they will be custom to fit. Dumping into 2-1/2" dual exhaust with an X- over. Mufflers when needed.
TECH Resident
Joined: Jun 2011
Posts: 936
Likes: 472
Summit 8715R1 222/234 115+3 .600/.575 would work well in a 5.3L with <2500lbs and carb.
The extra exhaust duration will help get the spent gasses out, yet with -1* ATDC exhaust closing it'll mitigate exhaust reversion with shorty or mid-length headers. It's -2* overlap will give a good carb signal even with the single plane and that size carb, providing decent part throttle response; and have a really broad power range @ WOT (especially mid to upper). So if you do autocross, it'll get off the corners without too much downshifting and pull all the way to 7k. Probably just soft enough on the low end to keep from blowing the tires, but still feel really strong.
The extra exhaust duration will help get the spent gasses out, yet with -1* ATDC exhaust closing it'll mitigate exhaust reversion with shorty or mid-length headers. It's -2* overlap will give a good carb signal even with the single plane and that size carb, providing decent part throttle response; and have a really broad power range @ WOT (especially mid to upper). So if you do autocross, it'll get off the corners without too much downshifting and pull all the way to 7k. Probably just soft enough on the low end to keep from blowing the tires, but still feel really strong.
Last edited by 68Formula; Mar 14, 2024 at 08:41 PM.
Trending Topics
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
Isnt the summit ghost cam (8715R1) a cam for boosted motors?
I dumped all the cams above into dyno2000 just to have a comparison. short of a slight bump in power on the XER281 to the XER285, the others are about even.
the BTR hotrod cam is about on-par with the comp 281. however with higher lift than the comp. from a spring longevity point of view. there is a nod to the comp.
all have over 300 lb-ft of torque at 2000 RPM. all about 200 lb-ft more than it will take to spin the tires in first and second in a car that is 11 ft long and is having its wheel base stretched from 78" to 90" to fit the motor.
I dumped all the cams above into dyno2000 just to have a comparison. short of a slight bump in power on the XER281 to the XER285, the others are about even.
the BTR hotrod cam is about on-par with the comp 281. however with higher lift than the comp. from a spring longevity point of view. there is a nod to the comp.
all have over 300 lb-ft of torque at 2000 RPM. all about 200 lb-ft more than it will take to spin the tires in first and second in a car that is 11 ft long and is having its wheel base stretched from 78" to 90" to fit the motor.
Last edited by Scott Danforth; Mar 15, 2024 at 11:37 AM.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
TECH Fanatic
Joined: Aug 2009
Posts: 1,845
Likes: 255
From: Coast of San Mateo County Between Pacifica & HMB
Cam Motion LS1 Titan 3 ( 224/228 113+4 .603/.595) would be my suggestion for a medium aggressive 5.3 in a sub 2400 lb car.
Cam Motion is famous for smoother lobe profiles & exceptional customer service.
Easy enough to call and get something custom specced as well.
Cam Motion is famous for smoother lobe profiles & exceptional customer service.
Easy enough to call and get something custom specced as well.
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
TECH Resident
Joined: Jun 2011
Posts: 936
Likes: 472
It's actually not, but it still works well on boosted motors. So @Summitracing also listed it as their Stage 1 Turbo camshaft when they launched their turbo cam series. But it was originally listed as their N/A Stage 1 LS camshaft.
Don't get too attached to naming conventions. It's the valve events that are important.
Don't get too attached to naming conventions. It's the valve events that are important.
TECH Fanatic
Joined: Aug 2009
Posts: 1,845
Likes: 255
From: Coast of San Mateo County Between Pacifica & HMB
TECH Enthusiast
Joined: May 2008
Posts: 642
Likes: 572
From: Carnation, WA
I drive my LS3 Miata on the street essentially daily. It’s 2400#. When I had a rowdy cam in it, any lack of manners due to the cam was reflected *immediately* in jerky behavior of the vehicle. I went to a milder cam (227/232 114LSA) and the car drove much nicer. I think the OP is on the right track with a 224/228 cam. Given that it’s only a 5.3, if it was me, I’d go milder … but I’m super old. 🙂
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
I drive my LS3 Miata on the street essentially daily. It’s 2400#. When I had a rowdy cam in it, any lack of manners due to the cam was reflected *immediately* in jerky behavior of the vehicle. I went to a milder cam (227/232 114LSA) and the car drove much nicer. I think the OP is on the right track with a 224/228 cam. Given that it’s only a 5.3, if it was me, I’d go milder … but I’m super old. 🙂
TECH Enthusiast
Joined: May 2008
Posts: 642
Likes: 572
From: Carnation, WA
I’m a neanderthal … neanderthals like to row their own gears. 🙂
TECH Resident
Joined: Jun 2011
Posts: 936
Likes: 472
Thread Starter
Launching!
Joined: Mar 2024
Posts: 287
Likes: 85
From: Bradentucky Florida
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.