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PQ290Enticer 01-12-2023 08:00 AM

So I'm thinking the answer is no however, If I tear down to the short block, is there any way to verify piston to wall without piston removal?
snapmorgan, I may have posted this already but the top ring gap is listed @ .020 on one engine and .021 on the other. I suppose this could be "actual"? Is that too close? I think that the jury is out whether the engines with almost 800 hrs on them retained the stock bore dimension as noted on the paperwork so the stated "standard piston" to bore is in question @ .002.
BBYSTWY, that is a bummer. I'm not sure but did they use the wrong poly locks? Am I mistaken that they rubbed the rockers? I did buy an afr system that will monitor both engines. The dyno showed upper 12's and low 13's so I feel comfortable at least starting the engines in the boat environment. Never going to be boosted in any way. I think this package is all and more than my boat needs or wants.

BBYSTWY 01-12-2023 08:04 AM

Correct on the poly locks...those were also too short however the geometry caused by the wrong push rods didn't help the situation lol

snapmorgan 01-12-2023 08:22 AM

According to the KB chart that you posted, end gap should be .02975. We will just call it .030. If yours are truly .021, no bueno.

PQ290Enticer 01-12-2023 08:36 AM

Of course it is. Still waiting for the original builder to contact me. More ammo for my case I suppose.....

PQ290Enticer 01-12-2023 09:20 AM

So I looked over the invoice and getting back to my question about how much I should ask the original builder for as far as him installing the pistons with the incorrect clearance for the pistons to wall based on the manufacturer, I come up with $2,120.00. Disassemble, hone to specs, and reassemble. That's assuming the rings will still work and seeing how the end gap is tight as is maybe just perfect after. I don't have money it this for gaskets or shop materials. He will not be doing the work so I need to be fair however I do have to pay another shop. Any thoughts on this?

BBYSTWY 01-12-2023 09:46 AM

As some one who has gone through this...I wish you luck my friend! I think you made the blood from a turnip reference...shops don't like to give money back for services rendered regardless of the situation..I sought legal console in my case and was told that it would cost more in legal fees than what I would get back...sucks but that's the world we live in unfortunately

Full Force 01-12-2023 10:04 AM

As for tuning, I refuse to run engines in a boat without a wideband, gives you very good idea what's happening in boat...

PQ290Enticer 01-12-2023 01:36 PM

On post #74 (geez should I start another one? 2nd dyno complete?) I have the piston sheet listed. I want to make sure I'm reading these extremely small dimensions correctly. I was thinking that the end gap on my rings was really tight however the KB Piston sheet shows "Ring End Gap Factor" of .0070 for a n/a marine engine with a bore of 4.1" and up. I don't know if the word "Factor" means that there's a formula that you use or is it straight up that dimension. From my actual build sheet, my ring gap on the top ring is .021. That's a lot wider than what is required correct? I just noticed the extra "zero" on the piston sheet. Now I'm wondering first, am I correct. 2nd, is the gap too large?

PQ290Enticer 01-12-2023 01:38 PM

Full Force, I did by this unit.

Innovate DLG-1 Dual Lambda Air/Fuel Ratio Gauges 3891

It will monitor one bank of each engine. I'm hoping that is enough. FYI I'm using a QFT M-800 double pumper with the RPM Air Gap.

snapmorgan 01-12-2023 02:33 PM

You multiply that .007 factor X your bore diameter. It says it in the top paragraph just to the right of the chart


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