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KingLT1 is gonna kill me for this but why the heck not ask the knowledgeable TECH guys for opinions
He owns this beautiful rig with 215,000 miles on the original unmolested 5.3
Gorgeous
I'm pretty sure he's been considering a reman LQ4 with a 212/218 cam
Vehicle has thirty inch tall tires and 3.73 gears, stock converter
I proposed to him an LS1 with 862 heads, 216/224 .533" lift. 117LS 114ICL CAM
Shorty headers and possibly a TBSS converter
The compression ratio on this LS1 could be 11:1 with .060" Cometics or 11.27 with GM .051 MLS
Hopefully King will chime in with additional data but the main questions are: can this smaller yet higher compression LS1 make daily drivable torque;similar to an LQ4 ?? Would the valve events of the proposed camshaft work with mid grade fuel or is premium needed ?? Thoughts on driveability and if he were to stay stock converter and cast iron manifolds.
Forgot to add: He's a pretty good self tuner with the HP stuff so that part of the equation is a set GIVEN
The engine would be based on a LS6 block. I use this truck for pulling my boat. Not worried about how hard it pulls up top as much as low speed tq. I want to be able to kick it down and pass with the boat on back. Lol
Personally, I had my mind made up on a iron 370 with 317's and a 212/218 cam.
Trying to see if my original Vette short block and those 862 heads I just freshened could work for his application. I picked the 216/224 cam so the cylinder pressure wouldn't be too high and this wide lobe separation with an IVC point of 42 ABDC "should" create a long flat torque band. Like over 300rwtq from 2500-6000 rpms. However. I am no valve event expert
Last edited by A.R. Shale Targa; 11-01-2016 at 12:57 PM.
I ran a set of Borla shorties in my Pewter 99 Silverado Z71 with the then weak *** 270 horse 5.3 and they performed as advertised, roughly 8 or so ponies. Not a **** ton but certainly a noticeable increase
If you want to do that, maybe talk to someone about cam specs for the specific application.
I am not sure what kind of gas and quality is available near you guys. The compression might be on the high side though for a DD street beast.
I can get up to 93 octane around here, however I would prefer it to be at least 89 friendly...The compression seems a tad high imo as well for the application, but I am no expert. Perhaps I will shoot a few emails to Martin, TSP, BTR, and see what they think.
I can get up to 93 octane around here, however I would prefer it to be at least 89 friendly...The compression seems a tad high imo as well for the application, but I am no expert. Perhaps I will shoot a few emails to Martin, TSP, BTR, and see what they think.
I know you can do a lot with cam spec's in terms of bleeding of cylinder pressure and so on.
I myself wouldnt run over 10.5:1
I have run my bone stock LQ9 on 87 with no knock or pinging but it runs better on premium 91 and the fuel milage is better as well.
I know you can do a lot with cam spec's in terms of bleeding of cylinder pressure and so on.
I myself wouldnt run over 10.5:1
I have run my bone stock LQ9 on 87 with no knock or pinging but it runs better on premium 91 and the fuel milage is better as well.
It does seem to be all about cylinder pressure and not exactly static compression. My 03 Silverado SS had the 10:1 LQ9 (196/207@.050) which ran better on 93 and with a tune only was a 14.80 rig @ 5500 pounds (AWD) My buddy had upped the factory timing from 21 to 24 but when we hit the MAF with a .061" jet, he put it back to 21. With colder plugs on 93, it would pull 2degrees on the hit and ramp it back in. Pretty good fuel system to take that much dry shot. The mph jumped from 90 to 106
I'm sure Kip could make a stick to work the pressure down to mid grade friendly but the timing would need to be near factory stock.
To me the logical choice between the two would be the LQ4 since the vehicle is used to tow and low speed torque was mentioned as a primary goal. I would assume the additional cubic inches and truck intake manifold would provide better low end torque versus a 5.7 ls1 motor with a ls1 or ls6 intake manifold. Honestly, if it were me I wouldn't even waste the money installing a cam or headers onto the LQ4 because a stock LQ4 as is should be a significant step up from the 5.3 in the low-end torque aka towing department. Just my .02
FWIW, my Dad has the L33 5.3 in his truck which is the aluminum 10.0:1 motor, it doesn't like 87 too much, runs better on 89. I'm sure there are additional variables to consider but I probably wouldn't go higher/much higher than that from a compression standpoint unless you are willing to put 93 in it.
Either way, I would choose a different cam for driveable torque.
From personal experience, I try to keep the LSA down to 114 or less in anything over 4500 lbs.
Stealth, I agree!! Fwiw the LS1 combo would get the truck intake off my 5.3... Still not sure I want that much compression and cam for the Yukon.
I believe you can go up a size or 2 on cam in the 6.0 and actually gain a little low speed tq. the 205/210 114 would make more tq and pwer from 1500 rpm on up with no mileage loss and would run on a basically stock tune. It should make another 30whp and 20wtq over the stock cam.
Thompson has reman lq4 long blocks for 2999.00. I have been looking at that option and picking up a cam motion drop in 205/210 cam. You might ask why not just have Thompson do the cam, well the answer is they want you to purchase the 4500.00 long block and then they will install the cam of your choice. I see it as wasted money because I do not need Pac springs, melling oil pump, or a billet timing set for a application like this. Stock stuff works fine and is plenty reliable.
Another option is find a lower mileage complete 6.0. Those can be had for around 2200.00 with 60-80k miles. Getting a little harder to find with that mileage.
Stealth, I agree!! Fwiw the LS1 combo would get the truck intake off my 5.3... Still not sure I want that much compression and cam for the Yukon.
I believe you can go up a size or 2 on cam in the 6.0 and actually gain a little low speed tq. the 205/210 114 would make more tq and pwer from 1500 rpm on up with no mileage loss and would run on a basically stock tune. It should make another 30whp and 20wtq over the stock cam.
Thompson has reman lq4 long blocks for 2999.00. I have been looking at that option and picking up a cam motion drop in 205/210 cam. You might ask why not just have Thompson do the cam, well the answer is they want you to purchase the 4500.00 long block and then they will install the cam of your choice. I see it as wasted money because I do not need Pac springs, melling oil pump, or a billet timing set for a application like this. Stock stuff works fine and is plenty reliable.
Another option is find a lower mileage complete 6.0. Those can be had for around 2200.00 with 60-80k miles. Getting a little harder to find with that mileage.
Damn, if that's the case then a very mild cammed LQ4 should make that thing a whole new truck!
I hope so it has new everything else...Rebuilt trans, transfer case, front diff, ball joints, control arms, tie rods, pit man/idler, shocks, bushings, alignment, wheels/tires, head lights/tail lights, grill, all led interior/exterior, new delco water pump, egr valve, plug wires, plugs, fuel pump, breaks/break hoses, driver seat been reconditioned, new stereo system...etc
Can't complain too much...My dad sold it to me 5yrs ago with 130,000 mile for 6k. He bought it basically new, was always garage stored. I have put 7500.00 in it so far.
It takes 30,000 dollars + to buy anything newer in this good of shape. So even if I drop a motor in it, I am still ahead and no payment.
Well, according to Kip, too much weight and compression to make a cam work for mid grade fuel. Premium 93 and a bit of stall(TBSS) he thought he could tackle that but not to be for 89-90 octane. He suggested that it could really act like an LQ9 on E85 but the needed injectors plus availability makes it a no go for the King. Well, no harm in asking
Thanks for all the informative replies.
10-30-2016, 04:42 PM
LM7 to LS1 swap/truck application 
