Truck cam question
Stock cam, a good converter and a good tune, lol. Also long tube headers and a good Y-pipe into a free flowing muffler. Then later on add a small cam.
The Ram I mentioned above ran 8.90s with the stock manifolds, cats & Y-pipe.
I put long tubes, built a 3" to 3.5" Y-pipe and had a magnaflow on it. I put a pair of 3" cutouts on it. The Ram then went 8.60s on the 20s. Ran 8.30s on 29" tall 17" drag radials and 17" wheels.
I can take a stock engine, add long tubes, decent exhaust, a converter and the tune it and beat a cam and tuned truck any day of the week.
https://youtu.be/uEvDiVKZ_1Q
The Ram I mentioned above ran 8.90s with the stock manifolds, cats & Y-pipe.
I put long tubes, built a 3" to 3.5" Y-pipe and had a magnaflow on it. I put a pair of 3" cutouts on it. The Ram then went 8.60s on the 20s. Ran 8.30s on 29" tall 17" drag radials and 17" wheels.
I can take a stock engine, add long tubes, decent exhaust, a converter and the tune it and beat a cam and tuned truck any day of the week.
https://youtu.be/uEvDiVKZ_1Q
The converter was not double the difference but the 383 is also very healthy.
I went from a 9.6:1 350 making 350 hp and 400 tq to an 11:1 6" rod 383 making better than 475 hp and tq. It is L31 Vortec based but not a many parts of the L31 remain. The new engine has Lloyd Elliot ported aluminum heads, a 218/228 comp roller cam cut on a 110 lsa installed on a 106 ICL. It has Rhoads VMax lifters cold lashed at 0.014" The lifters knock about 20° duration off the cam at low engine speeds. It has 1.7 rockers on it giving the cam 0.578" lift. I had previously ditched the stock L31 intake with all the spider garbage in the plenum for a L31 crossram marine intake with external injectors. I swapped it out for a Mercruiser MPI Mag dual plane MPI intake that has been gasket matched/ported to match the ~210cc heads. I had already converted the old 350 to the EFI connection 24x setup and Delco D585 coils. The 350 was also DBW using an 8.1 van throttle body, accelerator pedal and TAC module. I swapped the 78mm TB for a GM 87mm LS2 throttle body on a holley 17-94 adapter. The new engine has 4" silicone and aluminum ducting to the factory 2001+ express van air cleaner. The 350 had Thorley Tri-Ys into the factory 3" exhaust piping. I replaced the factory cats when the headers went on for 3" Thunderbolt cats. I replaced the stock muffler and 2.75" tailpipe for a dual 3" in single 4" out muffler and added a 4" tail pipe with the headers as well. The 350 ran really well. The 383 runs much better.
The pistons ended up 0.015" down the bore and I used a 0.028" compressed head gasket. At 0.043" quench I run 87 octane not towing with the total timing at 29° @ 3,600 rpm at WOT with a 12.5:1 WOT air/fuel ratio. When I tow, I run 91+ octane and it still runs detonation free. With E85 in the tank it runs at 34° total timing and makes a decent bit more power.
The converter was built by a local performance converter builder. It is a GM B82 that has been re-stalled by re angling the fins. The fins were hand brazed to help prevent fluid from bypassing them which helps efficiency. The converter tolerances between the impellor, stator and turbine were drastically tightened also helping fluid flow as designed. By making more fluid flow in the correct manner (impellor through the stator through the impellor) without bypassing the efficiency is improved and heat production minimized. Part-throttle slippage is also minimized. The lockup clutch was replaced with a carbon fiber material so that it will handle the torque and abuse. The front cover was replaced with a billet cover as well. The GM B82 converter already has a high stall torque ratio and the changes should have actually improved them. I think the factory converter is a 2.1 STR. After revisions its about a 2.4 or 2.5 STR. It drives very well. 0-40 mph performance was noticeably improved. Its basically what they build for trucks that tow and motorhomes but has been loosened up for higher stall speed. Above the stall speed the converter only slips about 150 rpm at 4,000+ rpm which I feel is very low for a ~2,800 stall speed.
When I have Tow/Haul engaged I have the PCM locking the converter immediately after the 1-2 shift and keep it locked after that. The only time the programming unlocks it is during a downshift and it relocks immediately after. Not towing I run the 383 to 6,000 rpm. Towing I shift it at 5,200 rpm. Starting off from a stop light under normal acceleration the transmission upshifts at about 3,000-3,500 rpm. With LT265/75R16s and 5.13 gears the converter is locked by the time I hit ~30 mph. In my application with the way I tuned it, the converter does not bother me at all.
I went from a 9.6:1 350 making 350 hp and 400 tq to an 11:1 6" rod 383 making better than 475 hp and tq. It is L31 Vortec based but not a many parts of the L31 remain. The new engine has Lloyd Elliot ported aluminum heads, a 218/228 comp roller cam cut on a 110 lsa installed on a 106 ICL. It has Rhoads VMax lifters cold lashed at 0.014" The lifters knock about 20° duration off the cam at low engine speeds. It has 1.7 rockers on it giving the cam 0.578" lift. I had previously ditched the stock L31 intake with all the spider garbage in the plenum for a L31 crossram marine intake with external injectors. I swapped it out for a Mercruiser MPI Mag dual plane MPI intake that has been gasket matched/ported to match the ~210cc heads. I had already converted the old 350 to the EFI connection 24x setup and Delco D585 coils. The 350 was also DBW using an 8.1 van throttle body, accelerator pedal and TAC module. I swapped the 78mm TB for a GM 87mm LS2 throttle body on a holley 17-94 adapter. The new engine has 4" silicone and aluminum ducting to the factory 2001+ express van air cleaner. The 350 had Thorley Tri-Ys into the factory 3" exhaust piping. I replaced the factory cats when the headers went on for 3" Thunderbolt cats. I replaced the stock muffler and 2.75" tailpipe for a dual 3" in single 4" out muffler and added a 4" tail pipe with the headers as well. The 350 ran really well. The 383 runs much better.
The pistons ended up 0.015" down the bore and I used a 0.028" compressed head gasket. At 0.043" quench I run 87 octane not towing with the total timing at 29° @ 3,600 rpm at WOT with a 12.5:1 WOT air/fuel ratio. When I tow, I run 91+ octane and it still runs detonation free. With E85 in the tank it runs at 34° total timing and makes a decent bit more power.
The converter was built by a local performance converter builder. It is a GM B82 that has been re-stalled by re angling the fins. The fins were hand brazed to help prevent fluid from bypassing them which helps efficiency. The converter tolerances between the impellor, stator and turbine were drastically tightened also helping fluid flow as designed. By making more fluid flow in the correct manner (impellor through the stator through the impellor) without bypassing the efficiency is improved and heat production minimized. Part-throttle slippage is also minimized. The lockup clutch was replaced with a carbon fiber material so that it will handle the torque and abuse. The front cover was replaced with a billet cover as well. The GM B82 converter already has a high stall torque ratio and the changes should have actually improved them. I think the factory converter is a 2.1 STR. After revisions its about a 2.4 or 2.5 STR. It drives very well. 0-40 mph performance was noticeably improved. Its basically what they build for trucks that tow and motorhomes but has been loosened up for higher stall speed. Above the stall speed the converter only slips about 150 rpm at 4,000+ rpm which I feel is very low for a ~2,800 stall speed.
When I have Tow/Haul engaged I have the PCM locking the converter immediately after the 1-2 shift and keep it locked after that. The only time the programming unlocks it is during a downshift and it relocks immediately after. Not towing I run the 383 to 6,000 rpm. Towing I shift it at 5,200 rpm. Starting off from a stop light under normal acceleration the transmission upshifts at about 3,000-3,500 rpm. With LT265/75R16s and 5.13 gears the converter is locked by the time I hit ~30 mph. In my application with the way I tuned it, the converter does not bother me at all.
Your build on your truck, and the way you tuned your lockup really remind me of how I did my camaro. I used to wear cammed cars out with my bolt on and stalled car. Everyone also pressed me to cam that car and the truck I had after it, and the one I have now, and yet they perform better than a lot of cammed vehicles. I prefer to do every little detail before doing the cam. Well though out bolt ons and a tune and the right stall (hell sometimes even without a stall) > cam and slapped together setup any day.
TECH Resident
Joined: Oct 2006
Posts: 986
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From: Euless, TX
Just a little tci 3500 in my 85z28. But I'm not a weekend warrior either. I've build many cars and dyno tuned them. Just never a baby cam in a full weight dd SUV and wanted to know what over cams. I think my guidelines were simple to follow. Low lift. Using ls3/6 springs and not buying a tq convrtr. Any responses that didn't might my criteria = pointless. How many ppl chimed in without reading my o.p.?
I actually just finished installing a cam, lifters and stock 5.3 heads on a LQ4 and tuning it this past weekend. It was a stock LQ4 with an edelbrock proflow and 2010 camaro manifolds into a dual 3" exhaust with a x-pipe and flow masters backed to a stock 4L80E with the stock converter that stalls ~2,200 rpm. It is shoved into a 71 Chevelle with a 4.10 gear and 325 wide drag radials on the back.
My friend is a cruiser and the car rarely ever exceeds 3,500 rpm. But when he does exceed 3,500 rpm he wants it to go. He also likes it to sound good and have stock manners driving. He wanted more low-end grunt from the 6.0L.
The 6.0L broke a plastic lifter bucket/retainer, spun the lifter and ate the cam. After several weeks of conversations about what to do. I talked him into a pair of junkyard 862s that were cleaned up, valve job and decked 0.020" by a machine shop. BTR double springs. For the cam we went with a cheap 228/230 Elgin. For the lifters we went with Rhoads original. Once it was back together and tuned, it makes more power everywhere. It has a slight valvetrain noise that resembles a tightly lashed solid roller cam. The knock sensor does not pick up any of it. With the MAF disabled I had to add fuel practically everywhere to the VE table for the increased airflow of the cam. Slight tweaks of the MAF and timing tables. Car idles at 550 rpm with 18.5 in/hg vacuum. When you put it in gear it maintains its smooth idle. When you pull away from a stop at light throttle the 80E shifts into 2nd at about 5 mph. Shifts to 3rd at about 15 mph and into OD at 23 mph. Then locks the converter about 33 mph. Give it more throttle and it shifts about 3,000 rpm and it is already building enough torque to shove you nicely into the seat. At WOT the 6,200 rpm shift points come quick and it has more than enough power to easily break the 325 drag radials loose. I tuned the car with a wideband. I enabled lean cruise and it runs at 16.9-17:1 at 2,600 rpm at 70 mph on the highway while pulling 19 in/hg manifold vacuum. On 87 octane it runs 26° total advance at WOT and up to 52° in lean cruise. You could not ask for a more balanced, spirited cruiser. We cruised it 150 miles on sunday afternoon. Car had previously gotten a best of 25 mpg. On our highway cruise it averaged 29 mpg.
If you consider a cam, consider new lifter buckets, a higher lift cam, double springs, and rhoads original lifters. The original rhoads lifters will knock about 15° duration off the cam at lower rpm and save yourself the aggrevation of losing low-end torque and idle vacuum yet still give you the top end charge of the cam you chose. At idle and low rpm that 228/230 cam is like having a 213/215 cam.
Just showing how effortlessly the car cruises down the highway with all the low-midrange torque this setup makes.
Last edited by Fast355; Nov 26, 2019 at 01:38 PM.
