Dominant saw V4 371 build

[huskyboy]

Atleast I think. I think the popup is hitting the chamber that is, I just dont know, but sumthin is hitting at top dead

Spark plug?

 

[Funky sawman]

Nope, pulled coil and plug out to eliminate that

 

[Marshy]

Nope, pulled coil and plug out to eliminate that

Got any clay? Shouldn't need much.

 

[Ronie]

You could try painting the popup with fingernail polish and seeing where it leaves a mark. Acetone will take it back off the piston.

 

[Marshy]

Machinist blue dye should work also if you have some. Plus the smell will take you places if you breath it too long.

 

[Funky sawman]

I will try to tear it down today, such a big job, feels like I'm doing an inframe in a new peterbilt

 

[Funky sawman]

It doesn't lock up the saw, but you can hear and feel the piston slapping the head lightly

 

[Funky sawman]

Ok with a hunker down and get it done or die attitude, I got the cylinder off yet again. Something I notice is the base gasket that came with the kit is much thinner than the base gasket that I ordered separately. I dont have another thick one to try.

 

[Funky sawman]

I will get a gasket measurement when me wife gets back with a battery for my calipers

 

[Ronie]

What was your squish with the thinner gasket? Sorry if you've already said.

 

[Funky sawman]

Around 16 thou.

 

[Funky sawman]

Rough number cause I measured 5 times and got 5 results arggggg

 

[Funky sawman]

Regardless, this is supposed to be a plug and play piston, if it is indeed a gasket issue then that's an easier fix

 

[Funky sawman]

Only hobbies I have left are firearms and saws. Running into issues like this make me just want to throw in the towel. The firearm side of this has allready put me through the ringer with 1500 spent last year on a custom mk5 weatherby in 340, that the gunsmith really screwed up and ruined the euro mark wood stock and a 450 dollar shilen barrel. He cut the threads wrong and barrel was not true to reciever. What a nightmare. I gave it to my dad, telling him it ain't worth a heart attack thinking about it.

 

[Ronie]

I'm not an expert but I would find out exactly where it's touching and go from there. If it's just a small area you could take enough of the piston in that spot to give you enough clearance. I wouldn't just put a gasket that's a little thicker on it because it wouldn't give you much clearance in the area that it's touching now.

 

[XP_Slinger]

Rough number cause I measured 5 times and got 5 results arggggg

Since you have the cylinder off, you can measure squish more accurately by sticking pieces of solder to the piston at the 12, 3, 6 and 9 o’clock positions. All measurements should be very close to each other if not the exact same.

 

[XP_Slinger]

Only hobbies I have left are firearms and saws. Running into issues like this make me just want to throw in the towel. The firearm side of this has allready put me through the ringer with 1500 spent last year on a custom mk5 weatherby in 340, that the gunsmith really screwed up and ruined the euro mark wood stock and a 450 dollar shilen barrel. He cut the threads wrong and barrel was not true to reciever. What a nightmare. I gave it to my dad, telling him it ain't worth a heart attack thinking about it.

You’ll get through this man, don’t throw in the towel just yet.

 

[Ronie]

Don't throw in the towel, It could just be a tiny spot where the combustion chamber starts sloping up.

 

[Ronie]

Before I had a lathe I put a 268 piston in a 372 that I had sanded down by hand, I ran it a bit and pulled the cylinder and I could see in the carbon where it had just barely been touching the cylinder. Took some sand paper to it, problem solved.

 

[Funky sawman]

I think I'm gonna sell that piston and just build the saw with factory piston. I'm completely out of basic resources. My solder is too thick to begin with and would have to buy solder. Excuses excuses I know but that's my life right now sorry