When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I apparently lost the info on what I used before () but think it was by Victor Reinz. I did not re-torque the head because it uses TTY bolts - not what I'm used to with older stuff, but as I understand it you torque to the specified value and that's all, period. Thanks - I'll look over the ones you mention, I'll probably try to order everything from Summit in one shot.
Anybody have a part number for ARP exhaust bolts/ ('92 LT1) For some reason I'm having trouble finding them.
Making a list for a Summit order. Weather is crappy, '66 truck project is in the garage so the C-4 is a driveway dweller. Might get the compression test done tomorrow.
Well, head gaskets are quite a rare event on the LT5 UNLESS you stray away from the old GREEN silicon base antifreeze. Marc Haibeck would have some data on that aspect. The only time the heads on my LT5 were off (back in 2010(?) was for porting. And, that said, the cams were re-phased (by Pete (the Greek) Polatsidis (not a common DIY job for us mortals). And, the appeal of having 510 hpw/o sacrificing mpg or idle quality is intoxicating!
Well, a decent day today and although I could not spend the whole time on the car, I did tear into it. I have 2 cylinders left to do the compression check (#6 and #8 ). Have gotten a good start on removing some other stuff, amazing how much easier it is the second time around, both knowing what to do, and everything having been apart recently.
I'm not going to post every step along the way, the thread linked in Post 11 does that. But I will share a few items and thought y'all might get a laugh from this. Last fall I took several cotton *****, soaked them with peppermint oil, and left them at various places around the car to keep the meeces away. Today I pulled the right side fuel rail cover off, and.....
Was this done on a cold engine? Also, what do the plugs look like? I suppose if these are cold numbers that it only starts to leak as it starts to warm up??? Just spitballing here but I'm with you as there isn't any smoking gun at this point. Very Strange!
Just got a similar thought from a buddy - no smoking gun on the compression and none of the plugs are white, in fact they look like it's a bit rich. He said he thought maybe a 5 or 10 minute warmup may not be enough to get rid of a winter's worth of condensation in the exhaust (the car was outside all winter, gas tank was totally full with non-ethanol gas).
I didn't go very far beyond what I had to remove to do the compression test, except the fuel rails and injectors. I'm thinking I'll put everything back together, pay attention to coolant level, check the dipstick often to be sure there's no cream in the coffee, and maybe it's just moisture boiling off. That would make my day!
Took these last night, rather poor quality but they clearly are not white from water. Found they were gapped .035 instead of .050 (my mistake from 2020), can that cause the over-rich appearance?
I'm putting things back together, but the torque wrench I need is at the other shop, a 25 minute drive each way. We may get out there in the next day or two, but it's supposed to turn cold and even possible snow over the next few days so according to the forecast it may be Wednesday or Thursday before it gets done. I'll check back in with an update when there's something to report.
Dont look horrible to me, every sbc will have afew that look darker. Tan is good just not black.
Do you have EFI? Have you put an 02 sensor in it to see what its doing?
Leakdown test really tells the tale. Cyl pressure as a whole is pretty decent.
From: SCMR Rat Pack'r Charter Member..Great Bend KS
Originally Posted by Railroadman
Seems strange, I did the head gaskets in 2020 nd drove it some, it sat the winter of 20-21, then drove it all last summer. Now this winter it lets go. Why not before?
Ah, the eternal question: "Why did it fail now??"
Answer: "Because yesterday was too soon, and tomorrow isn't soon enough."
It's a stock LT1, replaced the injectors in 2018 with a set from FIC, just under 4,000 miles on them. Have not done a leakdown test. It seemed to be running well at the end of last fall.
I'm going out to the other place today, i have to take a few totes of leaves to dump and I'll get the torque wrench - altho we may stay a couple days out there so I can work on the '64.
Answer: "Because yesterday was too soon, and tomorrow isn't soon enough."
I like that! Altho it's rare to have something fail in the driveway, when you don't really HAVE to have it running. Usually it's either in the middle of traffic, or miles from nowhere.
I have been thinking about this a little. Let's assume that there is indeed coolant getting into the combustion chamber somehow. You just replaced head gaskets using TTY bolts, and other than your comment about having had the engine run hot briefly (which could have warped a head as pointed out) there's no obvious smoking gun. And, when you run compression tests you get good numbers. Yes, okay, they are run with the engine cold, but even if you had a small leak that would open up at operating temps I would think that if you were really leaking coolant into the combustion chamber there would be some evidence of a compression leak, even a small problem, in the compression test maybe.
You don't see coolant in the oil right? You don't see any contaminants in the coolant reservoir either right?
The LT1 head / intake manifold joint has no coolant passages between the two. So really the only place(s) coolant could be getting into the cylinder are head gasket leak, crack in the head water jacket, crack in the block water jacket, etc.
Then I thought - Hey, what about the throttle body? You know how the IAC housing has that coolant passage underneath that bolts on to the bottom of the throttle body plate? Many people bypass this and cap it to keep the TB cooler. And I remembered, on the L98 there is a gasket there underneath between the bolt-on IAC housing and the throttle body itself. And in that gasket there is a separation between the coolant passages and the idle air port itself. If that leaks, between the two passages, you could get coolant into the intake manifold idle air and into all the cylinders as a result.
Your smoke in the photo seems to be coming from the right side more than the left but that could be just the way the exhaust is putting it out since the pipes are not true left-right isolated exhausts - so I don't think that means the right bank cylinder head is the only one involved.
Give it some thought. If I'm right it's an easy check, just drain coolant a bit below the level of the TB and take it off, making a careful check of that gasket between the IAC housing and the TB main assembly. If I'm wrong not much lost time / effort, especially if it saves you from a teardown. You could also run a pressure test on the cooling system, and if you have a borescope camera look down into each sparkplug hole to see if there is coolant draining into any of the cylinders. If there is not, but you still see pressure loss from the cooling system, that may validate the theory that your leak is not in the head gaskets themselves but elsewhere....
Altho I did the teardown during the gasket replacement a couple years back, I will admit that I'm not totally conversant with exactly how everything is plumbed and interacting there. What you say makes sense from what I'm remembering. I will admit I'm second-guessing myself now about smelling coolant. It was NOT overpowering. I did use a borescope, didn't see any obvious coolant and when I did the compression test I didn't notice any being blown out. You are right, there was much more smoke/steam from the right exhaust.
There is crap weather coming, already rain/snow mix where the other shop (and my torque wrenches) is and should be here shortly. After this evening, temps won't be above freezing until Wednesday and as I said, the car is outside. Stoking up the fire so the better half will be happy, and I think we'll stay here for at least the rest of the weekend. So I have a few days to plan the next step. I'm either going to put it together and fire it up to see if the cloud burns off, or follow your suggestion. If I run it and the cloud remains, that's the next place to tear down for sure.
I need to get the 64 to where we can put the body back on the chassis, that would free up half the garage out there and the '92 could be where it's warm and nice. I envy those who have a nice big 4, 6 or more-car garage, right at the home, and can just work to their heart's content!
UPDATE - PROBLEM SOLVED! Well, I am happy to say I feel foolish - I apparently was a bit paranoid from having a previous head gasket problem. There WAS no problem this time, except that I did not allow sufficient time for the exhaust system to burn off all the condensation from the winter. My old hot-rod builder insisted that with the plugs not showing white, the compression good all the way around, no discoloration of the oil, etc, it just didn't add up. "****, man, fire it up and drive that thing!" was his advice. We had a couple weeks of real cold weather, then some other things going on, but today I got it buttoned up (thankfully I had not pulled anything major off). I put about 5 miles on it this morning after letting it warm up 10 minutes in the driveway, and the white plume is gone.
So on one hand I feel like an idiot for hitting the panic button too soon, (look at the pic in Post #1 again and you'll see why I did) but I'm more than happy to have no serious problem. Thanks to all who offered advice and support, and now after a couple minor tweaks it's time to put more miles on it!
Glad it worked out for you! Sometimes things work out and that you don't have to go through the work and expense of a repair that you had already done is a really good feeling.
Now you can put your time into getting the C2 back together and getting it on the road.
Glad it worked out for you! Sometimes things work out and that you don't have to go through the work and expense of a repair that you had already done is a really good feeling.
Now you can put your time into getting the C2 back together and getting it on the road.
Yup - getting ready to install the windshield in the '64 in a week or two.
I’ve been going back & forth on possibly pulling my heads on my 89 since she’s all apart. I keep thinking of the benefit of a fresh set of heads with backcut valves & maybe bigger valves with ports cleaned up and a thinner head gasket to top it all off. However reading your story this morning kinda freaked me out. My luck with cars is never the best but I have a very hard time leaving well enough alone!!
Cornhusker, to me it looks like you're 90% of the way there. We all dread "project creep" where we add one thing after another. But if you have everything torn down that far already....well.... When I did the first tear-down, the only problem was with #7 cylinder. But I figured if they tend to go in the rear cylinders, could #8 be far behind? Sure enough, #8 was not too long for this world and it's a good thing I did both sides.
Why did you tear it down to this stage? Problem or just freshening things up? There's peace of mind if everything is taken care of. Yes, I jumped the gun fearing the worst this time but actually what was fixed in 2020 is still doing fine and hopefully will last for a long time ahead.
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette
Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.
) but think it was by Victor Reinz. I did not re-torque the head because it uses TTY bolts - not what I'm used to with older stuff, but as I understand it you torque to the specified value and that's all, period. Thanks - I'll look over the ones you mention, I'll probably try to order everything from Summit in one shot.
). Have gotten a good start on removing some other stuff, amazing how much easier it is the second time around, both knowing what to do, and everything having been apart recently.
