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Hello everyone. Hoping someone can help me figure out which Iron 6.0L I just bought. It came from a 2006 GMC 2500 Savana cargo van and has 317 heads. Vin from the van is: 1GTGG29U061115535
Since the is the "conversions and hybrids" I'd better talk about the car it's eventually going in. I've got a 1983 BMW 533i "E28" 4 door sedan that I've already converted to Ford GT40 5.0L / T-5 manual. Car runs well enough and is fun but LS power potential is far superior dollar for dollar.
Thanks Chris05! What is the N/A power potential of the LQ4 given the lower compression ratio (9.5:1?) vs the LQ9, LS2 or the L76 in my Silverado?
S.F.
Certainly not max potential, but check out my build thread. I made 420 RWHP (500ish at the flywheel) with an LQ4, stock L92 heads, LS3 intake, stock LS1 exhaust manifolds, and Lingenfelter GT11 cam (218/230 duration, .644" lift). This cam is pretty mild. Dyno sheet is in the build thread if you're curious.
Okay so I bought a LS1 F-body flywheel for my LQ4 and I'm confused on the starter. The LQ4 starter I pulled off the motor when I was freeing it from the FedEx van had two long bolts and the ones I see online for the F-body has a long and a short bolt. Are they interchangeable?
Should be fine with your truck starter,the earlier starters used different length bolts but the pattern is the same.
Well, like an idiot I forgot to grab it from under the van before getting in the 1 hour long line to pay (1/2 price sale at wrecking yard). Once I was in that line there was no way I was getting out of it, so now I've got to get a starter and bolts.....
Got a junkyard starter and ran some cold compression tests. Only 110 - 130 psi on them so this one needs a rebuild. Put 15 psi in the cylinders and with both valve closed you can hear the air bleeding past the valves....
Given I only paid $120 at the upullandpay it's not too much of a bummer, figured I could end up having to rebuild it anyhow.
I agree.
Pull the heads and get them surfaced, pull the valves and relap them all. New valves seals and the heads are done, and so are your compression and leakdown issues pretty much.
There are checks for the cylinders too, but I think a head rebuild will cure your issues without opening a potential can of worms.
so youre gonna rebuild the whole engine instead of just cleaning the carbon off the valves/and or lapping them?
Originally Posted by leftlanetruckin
I agree.
Pull the heads and get them surfaced, pull the valves and relap them all. New valves seals and the heads are done, and so are your compression and leakdown issues pretty much.
There are checks for the cylinders too, but I think a head rebuild will cure your issues without opening a potential can of worms.
Martin
Seems the general consensus is go through the heads 1st as i just got schooled in my other thread as well:
This is my first LS (for fun, got a L76 in my Silverado) and I am still learning what you can do with them. Last complete motor rebuild I did was 23 years ago on a 350 Pontiac... Obviously these motors have a much longer usable life than the old-school V8's.
Relap the valves yourself, and if you dont have a valve spring compressor just rent one from a parts store. Ends up being free when you return it.
I ALWAYS get head pressure tested and surfaced, but if they have indeed been tore into before you may need to get the heights measured to make sure they dont get too much taken off them.
04-12-2015, 08:14 PM
What do I have LQ4 or LQ9? 
