Hello,

I posted awhile ago with some concerns about the headgasket/oil leaks on my C5. I decided to remove the engine, and have made some good progress. I have some questions and it would be great to get some opinions for this forums.

1. Engine is removed and head are off. The piston sleeves look OK, my thought is just to get the heads machined and leave the rotating assembly alone. But I'm open to rebuilding the bottom end if I get some consensus here. If I go into the bottom end the costs start adding up!!!
2. I think now is a good time to replace all the gaskets. There was some seepage from the oil pan & there were 2 bolts of the front cover that were loose. I was thinking the following: Oil pan gasket, rear main seal, crankcase cover & obviously all the gaskets that come with the head gasket kit.
3. I have 853 heads and the gasket I'm removing was not a MLS gasket. Is it OK to use a MLS gasket to replace?
4. If I replace the camshaft, should I upgrade anything on the top end?
5. Anything else to complete while the front cradle is dropped? I'm replacing the rear brake lines since they are pretty rusty, just going to get some standard 3/16" line off rock auto and re-use the fittings.

 

I'm assuming you're talking about cylinders when you mentioned piston sleeves. This is just my 2 cents, but here goes......
IMHO, there's no reason to remove the entire engine only to rebuild just the heads and install new gaskets. As long as it is out, it makes absolutely no sense to go to all the work pulling the engine, pulling the heads, then pull the front and rear covers, and the oil pan, to replace all the gaskets and seals, but then leave the old rings and bearings in it. I mean, you'll have removed everything BUT the crank, rods, and pistons. Why not remove the last 5-10% of engine, and do it right??? Unless the motor has less than 30,000 miles on it, I'd ring and bearing it. At that point, you'll basically have a totally new engine. MLS gaskets are fine. I'd also install a new timing chain and gears, and maybe a new oil pump, depending on mileage. As for upgrading with a different cam, that depends on how you want to use the car. Best of luck to you....

 

I’m with Grinder on this. As long as the block can be cleaned and garage honed — not tapered or oversized cylinders — it won’t eat your lunch money.
I will note you have to check what mother Chevrolet did with great care. When inspecting crank and rod bearings keep the originals separate and in order — the factory can use half thousandth sized bearings to correct for a clearance issue, and fitting a nominal bearing to a half thousandth oversized journal doesn’t work well for long.

 

If I had the engine out one of the improved rear engine covers would be installed from C@S Corvettes, https://www.corvettepartscenter.com/...rear-main-seal

 

Engine just passed 100,000 miles. Timing chain, gears & an oil pump are all on my list to replace.

Okay I was on the fence but the whole re-main kit sold by Enginetech (RMC346AP) is actually cheaper than the header kit + Gaskets. So I'll plan to re-use the pistons, lightly hone the cylinders and use standard rings? I will have to hunt down that post, but I take it it's not as easy as ordering "standard" size replacement bearings.



Great way to get acquainted with the car and learn a thing or two about engine building !!!!

 

We hear back from some C5 owners that have well over 300,000 miles on their C5 LS, still running great, no significant oil use, no major engine issues.

If your LS was running well, no strange noises, good oil pressure, not using a lot of oil, I would not disassemble the short block - unless you plan to add another 200,000 miles to it.

If you do disassemble the short block, EVERY new ring gap should be verified and in general, larger gaps are more protective in inadvertent high engine temperature events.

 

You've probably heard about some folks having issues with the OE rocker arm trunnions. Many of those issues are caused by aftermarket, "higher lift" camshafts. Unlike aftermarket roller rockers, that have trunnion assemblies that will rotate 360*, the OE trunnions, for some reason, have a bearing assembly that only rotates a limited amount, and exceeding that amount of rotation, when using a higher lift cam, causes issues.

My point, is if you intend to install a higher lift cam, either replace the rocker arms entirely, with aftermarket rockers, or install an aftermarket trunnion upgrade kit in your OE rockers.

 

If you have notch in your heads, then dont use MLS-head gasket.

 

jim993 raises valid points. It's your car and you know it much better than the rest of us do. While it's easy for me to sit on my sofa and argue main and rod bearings are cheap, but it's also easy for me to remember how many times I've stripped or broken bolts out of nowhere. Ontario probably makes the idea moot, but I have a couple of excellent reference books on the LS1, particularly on which bolts are safe to re-use and which are not so much safe to re-use, etc.
Make sure you get the right hone and stones for the rings you use -- too coarse happens much too easily, and can screw up a cylinder in almost no time at all.

 

Hey Vette97sc,

Yes I have the notched heads. Are you sure you can't use MLS gaskets with that style of heads? I've seen a few conflicting pieces of information online.

Jim993/redzg,

Some differing opinions but since the price for the re-ring kit is pretty minimal I'm going to opt for new rings and bearings. It's already out and I have nothing but time, so it'll be a fun winter project for me. Thanks for the chart!

 

I believe ws6store sells a notched mls head gasket. I know they did but not sure if they still carry it

 

Looks like michigan motorsports has them

 

In the past I've had great luck with plain iron Hastings rings and a "Dingle Berry" hone. Really inexpensive, they break in easily and just work. Make sure you get the 45° crosshatch and correct end gap for the rings.
I just did a cam/head swap in the spring and used the GM head gaskets from the same year as the heads. BTW I found out the head bolts are block specific on these LS motors.

 

Aah they make now MLS gasket to notched heads now. About 7 years ago when build my previous C5 engine, i take heads to machine shop and they weld notch.