Thread: Certainly not what I expected.

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looking at the pic s ----it seems there is a lot of end clearance on the top ring but you say it is only 020---piston looks like a lot of clearance at top and you say you can rock it in the bore?? wrong size maybe???
Other things I have seen---wrong rings in wrong groove, rings upside down--all will result in lots of leakage

If you are going to just put back together change holes to see if problem moves

looking at the top ring it s end gap you could park a city buss in the end gap how about a LSi ring set 3.897 that piston takes a mm ring pack vtec pistons take a mm pack not sure on boat stuff hell it may not even get on the piston

Maybe that end gap is 200 thousands???

Originally Posted by jerry clayton

Maybe that end gap is 200 thousands???

hell jerry i do not know looking at the head bolt hole 7/16 looks 1/3 of that ? 145 ????????????? more or less looks like more ?it is about 1to 3 for every inch of bore adds 3 to gap well more like 3.1416 to .001 of bore so ????? i do not know what the rings are for not looking like 350?????? bad day at the ring shop?????

Has this been like that since you rebuilt it.
I had a motor that was done by a shop out in Vegas
and he had egg shaped the cyclinders.
Couldn't tell till we miked it, clevelands were bad for that
because at the top of the cyclinders flare out too except the huge valves.

Originally Posted by vara4

Has this been like that since you rebuilt it.
I had a motor that was done by a shop out in Vegas
and he had egg shaped the cyclinders.
Couldn't tell till we miked it, clevelands were bad for that
because at the top of the cyclinders flare out too except the huge valves.

he said he did get it out of a boat they just do not get that bad in a boat they rot thru befor that

As I mentioned, I put this motor together when I was trying for the $ 3000 budget so I simply had my machinist do a clean up hone, hot tank it, cam bearings, etc...........no overbore. The boat it came from had low hours and I used all Volvo Marine parts like rings and all to do a ring and bearing overhaul.

For the past two years its run fine, no smoke, good power. It has sat for the past 3 months or more because I've been working on the other car pretty much. I noticed it was starting to miss a little so I started exploring and found that compression issue. As for the rocking piston, now that I think about it the piston was only moving on the rings, and very slightly. The ring gap was fine at .0020, and the dots were up on the rings.

I am now pretty convinced carbon buildup caused the valves to not seal well. I ruled out heads initially because of the dip stick thing and also because these heads were brand new out of the box two years ago. But so much gas has been dumping into this thing and the fact most of my driving has been around town at low speed, it just got carbon fouled. It has to be that. Oh, the car also runs at about 150 degrees all the time, so I have to work to get the temp up and that should help. I bet I am getting incomplete combustion due to running cold.

I appreciate everyones feedback and suggestions. Here is a picture of the one ring inserted in the hole. You can see the small gap at about 2 oclock.

Don

So somewhere you said that it only gets up to about 150*? what is the cause of that? And why do you have so much fuel pressure?? like maybe how much??What kind of carb??

yep that photo looks better the other shot like jerry said it did look very big . if it was my engine or at the shop i would rap 3 or 4 clean rags around the crank tape off good crank over till crank is at BDC may be put some cardboad over the crank so you can not hit it when honing the bore and use a brm ball hone a just cut some glaze off that wall. wipe bore with clean rag with abit of oil on it wipe bore till it is clean

Jerry: When I put the car together I wasn't sure how it would cool and living in Florida I've had cars that ran hotter than I would have liked. So when I started driving this one and it ran so cool I was thrilled. However, that thinking was wrong now that I look back on it. The engine isn't coming up to a high enough temp to efficiently burn the gas so that compounded my problems.

As for the fuel pressure, I'm running a Holley red electric pump that supposedly puts out 7 psi and that was ok when I was running a single Edelbrock 600 cfm carb. But a year ago I bought one of Vintage Speeds 2 x 2 Rochester 2 gc setups and I understand they like about 3-3.5 lbs of pressure. So the combination of too much gas and not enough heat to burn it off seems like that might be what bit me. I'm heading to the shop now and will pull the thermostat and put a hotter one in there.......I think I put a 142 degree in originally.

Pat: I like that idea about the shop rags and cardboard. That will be what I do.

Don

I'd also use some honing oil on the bottle brush hone

and since you are planning onreplacing with a ford engine I would use cheapest rings I could find because they will set quicker

and yes put the hottest stat in you can find as that will help

any chance you could just run a mech pump???

Since its getting so cold up here Pat and I'll be down to help you

I don't have any experince with boat motors, I was just wondering about any machine work that might have been done. But I guess it would have run bad from the start.
Kurt

Originally Posted by jerry clayton

Since its getting so cold up here Pat and I'll be down to help you

HELL yes that is a date... talk about damp and cold crap . here in mich.. WE HAVE THAT . am not has old as some on here but my easy years of not working hard the doc tells me I am in my late 60s.my bones just love this cold and damp .. crap not looking for that white cold stuff

Originally Posted by jerry clayton

I'd also use some honing oil on the bottle brush hone

and since you are planning onreplacing with a ford engine I would use cheapest rings I could find because they will set quicker

and yes put the hottest stat in you can find as that will help

any chance you could just run a mech pump???

No, the Ford engine is going in my other car, the 27. This one will stay Chevy, but I do have another 350 Vortec engine that I will probably start building for it after the 27 is on the road. As for the mechanical pump, there is no room on that side for one but if I put the regulator in there it should help. I actually like electric pumps for the fast priming thing, but on my Ford I am going to run a mechanical.

Kurt: Yep, it has been on the road for exactly 2 years now and has been to Daytona twice and Billetproof once, so if there was a problem it would have surfaced long ago.

I worked on it today and pulled the rest of the valves out of that head and it's now pretty apparent to me the two valves in that cylinder alone were to blame. They were totally black, not with just soot but baked on shiny carbon, even on the seating areas. All the other valves were black, but totally clean in the seats. Evidently that cylinder, being the furthest back and the lowest (due to the 3 degree tilt) got more gas than the others. Even the exhaust port on that side looked like a well used bbq grille with baked on grease.

I honed that cylinder, cleaned all the other piston tops up with a wire wheel, scrubbed the cylinder walls, and cleaned up the combustion chambers. Tomorrow I'll have them order me the rings and gaskets I need to put it back together. Now a lot is starting to add up. When I would rev up the engine and back off it would backfire and flames would come out of that header only. That started about 6 months ago or so. BTW, the thermostat was a 160 so I am going to put a 180 in there and get the temp up a little.

Once again, thanks guys for the advice.

Don