Ailing engine (Updated after teardown)

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the clean piston tops and chamber are 100% sucking water. the hi psi is probably from oil.

good catch before things went all brown and round on ya.

i agree on cometics if you can get them, but if the lead time is unreasonable i don't see why you couldn't just snap another set of felpros in there and ship it. i mean, you got how many years and miles out of 'em so why not run it back?
(and order a set of cometics as future insurance)
 
Newbomb Turk said:
How much timing are you pulling per pound of boost?
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I don't pull any timing. I have my timing locked at 31 degrees. It seems to work well for this engine. Remember it has been together for 11 years and about 1500 miles per year. And I drive it, not baby it, just ask the wife. lol

Jack
 
Coyote Jack said:
I don't pull any timing. I have my timing locked at 31 degrees. It seems to work well for this engine. Remember it has been together for 11 years and about 1500 miles per year. And I drive it, not baby it, just ask the wife. lol

Jack
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I would suggest a curve of some kind and getting a way to pull some timing with boost.

No head gasket will survive with that much timing at and around peak torque and then not pulling timing under boost makes it all the worse.
 
Coyote Jack said:
I just came back in from taking the drivers side head off. It was pretty much the same story as the passenger side, just not as bad. It looks like I am going to get out of this with just some gaskets.

I did check into what my pressures should be and it looks like with an 8.2 to 1 engine like I have my cylinder pressure should be about 155 psi. So the 168 was not that far out of line.

Here are a couple of photos of the drivers side.

Jack

View attachment 1716251665

View attachment 1716251666

View attachment 1716251667
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Jack, keep in mind those engine calculators and real life are often not the same. I already know you know that though. Yes, I agree. I think you came out of this pretty good IF you had to have a failure.
 
There is something else that I failed to mention for some reason. I think it is important in this discussion. When I was loosening the head bolts on both sides I could not believe how easy it was to turn some of them. I am used to really having to reef on the strongbar to loosen head bolts. Some of these I could loosen with one finger on the strongbar. Less than an 1/8 of a turn and they were loose enough to turn by fingers only. There were others that required some real effort to loosen. Most of the looser ones were the bottom bolts, (the short ones). These are ARP bolts.

Jack
 
Jack, as suggested earlier either the block or the heads need to be o ringed. Under normal street driving with the blower you won't normally have a problem. But when you get into it, the boost is trying to push the head gaskets out. That is ONE of the shortcomings of the SBM with only 10 head bolts per side. I had the same problem, albeit naturally aspirated with 13-1 compression in a 273 back in the early 70's. Ed Hamburger suggested I o ring the block or the heads and run his copper head gaskets. After I had the heads o ringed and used the coper gaskets, I didn't blow out any more head gaskets. Just my .02!
 
The RA needs of the cometic gaskets is not crazy. I searched the conversion to sandpaper grit to get an idea. I would not coat them, I did once and it leaked a bit. Dry from now on. Definitely stud time. Make sure the center rivet doesn’t get pinched between the head and the block. I have had it happen. I just remove it. A 50 RA is between 120-150 grit.
 
After lots of thought I have decided what I am going to do. I decide to go with the Fel Pro 1008 gaskets again. Reasons for this. I can get them locally, they lasted 11 years the first time, I do not have to remove the engine to have it resurfaced. That's a big one. Don't have to have the heads resurfaced. Less chance of water leaks. Cost, although not a big factor, does come into it a bit. I am going to install them with a 3 step torque sequence, then let them sit overnight and retorque them in the morning. I will then reassemble the rest of the engine. I will run the engine through 3 heat cycles and then retorque the heads again. After this I will retorque the heads once each winter.

I know some will not like this idea but it is what I am going to do. It is a quick and cost effective way to address the problem. Getting work done on an engine around here is sketchy at best. Wait times can be up to 6 months and I am not going to wait that long to get the decks and heads resurfaced.

Jack
 
Remember that detonation can create enormous cyl pressure.
Maybe it's not the gskts or o-rings.
Just curious if that plug was damaged by mishandling, or other .
Good luck .
 
I think people worry about the surface finish requirements too much. Especially on a deck surface that is not freshly machined.
 
Coyote Jack said:
After lots of thought I have decided what I am going to do. I decide to go with the Fel Pro 1008 gaskets again. Reasons for this. I can get them locally, they lasted 11 years the first time, I do not have to remove the engine to have it resurfaced. That's a big one. Don't have to have the heads resurfaced. Less chance of water leaks. Cost, although not a big factor, does come into it a bit. I am going to install them with a 3 step torque sequence, then let them sit overnight and retorque them in the morning. I will then reassemble the rest of the engine. I will run the engine through 3 heat cycles and then retorque the heads again. After this I will retorque the heads once each winter.

I know some will not like this idea but it is what I am going to do. It is a quick and cost effective way to address the problem. Getting work done on an engine around here is sketchy at best. Wait times can be up to 6 months and I am not going to wait that long to get the decks and heads resurfaced.

Jack
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I would probably do exactly the same thing.
 
furrystump said:
I think people worry about the surface finish requirements too much. Especially on a deck surface that is not freshly machined.
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One of those things you hear a lot from people who haven't tried it themselves... I asked my machinist (experienced race engine builder) if I needed to deck my 5.9 Magnum block to work with Cometics. He said not to worry about it, factory finish is fine. Engine has been together with ARP studs for 7 years and at least 10k miles, zero leaks. I don't think Cometics are really necessary though considering OP has iron heads and boost level is pretty moderate.

I agree with @Newbomb Turk, your total timing is too much; not that far off from a hot NA SBM. That gasket should have held up fine if it wasn't detonating. It should have boost timing retard or at the very least take out a few degrees with the current setup. I also bet your rod bearings are showing copper. The head bolts probably loosened up over time from the heads being lifted with the detonation.

Just because it lasted this long before something broke doesn't mean it was running perfectly... It is a Mopar after all, they got the beef to handle abuse.
 
Inertia said:
Remember that detonation can create enormous cyl pressure.
Maybe it's not the gskts or o-rings.
Just curious if that plug was damaged by mishandling, or other .
Good luck .
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None of the plugs were damaged. One was fouled a little. I run my fuel mixture a little on the rich side to start with and that is what 7 of the plugs showed. It was just #6 that was fouled and that was the one that the gasket showed as the worst.

Jack
 
Coyote Jack said:
I started my 340 up this spring and noticed a **** load of blow by. I finally got around to doing some tests on it today. Compression is all over the map. There is light blue smoke coming out of the tail pipes. And you can see the amount of blow by in the video. The plug check showed all cylinders a little rich except #6 which showed a little oil fouling. The car still pulls like a freight train. Keep in mind this is 340 with a roots 6-71 blower on top. I am pretty sure a complete refresh is in order. Rings, bearings and a hone job for sure.

Compression test results:
1------128
2------121
3------120
4------118
5------122
6------95
7------112
8------168

What do you think?
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Since this engine was together for so long with zero issues is there anyway you fired it up this year on old pump gas. I just wondering if it got stale on you. As far as retorquing head bolts as often as you do you are stretching your bolts year after year if you aren’t replacing them. Good luck. Ohhhh I would put a machinist straightedge on those areas you pushed the head gaskets at a bare minimum.
 
pittsburghracer said:
Since this engine was together for so long with zero issues is there anyway you fired it up this year on old pump gas. I just wondering if it got stale on you. As far as retorquing head bolts as often as you do you are stretching your bolts year after year if you aren’t replacing them. Good luck. Ohhhh I would put a machinist straightedge on those areas you pushed the head gaskets at a bare minimum.
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The retorquing is something I was thinking of doing not what I have done in the past. A straight edge goes on it tomorrow, I didn't get a chance to look at it today. Life got in the way.

I did put 5 gallons of fresh gas in before I started it in April. I did start it a couple of times during the winter though.

Jack
 
Coyote Jack said:
The retorquing is something I was thinking of doing not what I have done in the past. A straight edge goes on it tomorrow, I didn't get a chance to look at it today. Life got in the way.

I did put 5 gallons of fresh gas in before I started it in April. I did start it a couple of times during the winter though.

Jack
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Don’t get carried away on the retorquing. I torque mine twice on the engine stand and never again.
 
My dad taught me to retorque the heads, headers and intake after a heat cycle and snug the tins and carb. an old habit.
Right or wrong a lesson learned from dad I'll take to the grave.
 
MiradaMegaCab said:
https://www.scegaskets.com/wp-content/uploads/2023/11/ICS-TITAN-INSTALLATION-INSTRUCTIONS.pdf
Integral O-Ringed Copper Head Gaskets

https://www.scegaskets.com/wp-conte...ER-HEAD-GASKETS-INSTALLATION-INSTRUCTIONS.pdf
For the ultimate seal and protection from head lift or aggressive total timing applications, O-Ring the heads and cut Receiver Grooves in the block.

With that said, 31* of Total Timing is a lot for 9PSI of Roots boost.
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I started out at 28 degrees. I slowly upped 1 degree at a time to the 31 degrees. I even drove it trying to get a ping out of it and never did. The engine just seems happiest at 31 degrees. I even upped the boost to 12 lbs once and got on it for a couple of short bursts. The only thing that did was break a balancer and timing cover. Sure was fun on those 2 bursts though. lol That was a few years ago now and maybe that was the start of the gaskets migrating. Who knows? I know I don't.

Jack
 
Coyote Jack said:
I started out at 28 degrees. I slowly upped 1 degree at a time to the 31 degrees. I even drove it trying to get a ping out of it and never did. The engine just seems happiest at 31 degrees. I even upped the boost to 12 lbs once and got on it for a couple of short bursts. The only thing that did was break a balancer and timing cover. Sure was fun on those 2 bursts though. lol That was a few years ago now and maybe that was the start of the gaskets migrating. Who knows? I know I don't.

Jack
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You don’t need to hear detonation for it to do damage.

I can tell you without boost that 31 at peak torque is way too much. And you are at 31 and not pulling timing.

I’d bet everything you have (and a bunch of **** I don’t have) you are slowly killing it.

That’s too much timing without boost.
 
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