2g pistons in a 91 6 bolt block

[Coder24]

Ok i have 2g pistons on 1g big rods. The pistons are STD. Does this mean they will drop right in to the 6 bolt block without having to bore it out? or is that the STD for 2g? I searched for this and found nothing. Im really hoping i dont have to bore my cylinders out.

 

[peypey's ride]

As far as I know the bore sizes are the same. Do a good honing of each cylinder before dropping them in. You can do that much yourself, its easy.

 

[Coder24]

As far as I know the bore sizes are the same.

Thanks...by the way the timing cover looks sick.

Anyone else have any information to back this up?

 

[peypey's ride]

by the way the timing cover looks sick.

QUOTE]

Thanks!

 

[Spln_Hrd]

Both the 1g and 2g 4g63 blocks have a 85mm bore.

Check your p/w clearances and ring gap after you hone it. I also suggest a deck plate if you want a really nice job.

 

[Coder24]

Both the 1g and 2g 4g63 blocks have a 85mm bore.

Check your p/w clearances and ring gap after you hone it. I also suggest a deck plate if you want a really nice job.

dumb question...whats a deck plate?

 

[Coder24]

Both the 1g and 2g 4g63 blocks have a 85mm bore.

Check your p/w clearances and ring gap after you hone it. I also suggest a deck plate if you want a really nice job.

another dumb questions whats p/w...piston wall?

 

[My1GLaser]

I hate to bring it up, but I just went thru this on my recent rebuild. Depending on the mileage of the motor your cylinders might be too tapered although they seem to look fine. I was just going to re-ring my pistons also, but the end gap changed by .010 from the top of the cyl to the bottom of the cyl. So I had to go .020 over. Just a heads up so you can check the end gap at a few points down the cylinder to see if you have too much of a taper. I am not sure what the limit is, but that was too much for me to live with. Good Luck!

 

[Coder24]

I hate to bring it up, but I just went thru this on my recent rebuild. Depending on the mileage of the motor your cylinders might be too tapered although they seem to look fine. I was just going to re-ring my pistons also, but the end gap changed by .010 from the top of the cyl to the bottom of the cyl. So I had to go .020 over. Just a heads up so you can check the end gap at a few points down the cylinder to see if you have too much of a taper. I am not sure what the limit is, but that was too much for me to live with. Good Luck!

! no! i think ill be alright. or i hope...i had REALLY high milage but i had good compression before i bent a valve so i guess we will find out. thanks man.

 

[Spln_Hrd]

P/W is piston to cylinder wall clearance. You want to measure your cylinder bore in three spots vertically and then 2 spots horizontally. Hard to make sence of this but you need to know if it tapers(up and down) or if its out of round(pretty logical right?).

Then you need to measure your mistu piston wherever mistubishi's manual recomends measuring the skirt. I would guesse its and inch down and 180* of the wrist pin, but alot of manufacturers have differant methods.

A deck plate is something to simulate the cylinder head being bolted onto the engine when your machining it, So what you need is something with the same thickness as a head with an 87ish mm bore directly in the middle, then you bolt it down using whatever method you will use when your assemballing the engine. Including a similair head gasket and using the same lube on the bolts.

PM me if you need any thing bud.

 

[Coder24]

P/W is piston to cylinder wall clearance. You want to measure your cylinder bore in three spots vertically and then 2 spots horizontally. Hard to make sence of this but you need to know if it tapers(up and down) or if its out of round(pretty logical right?).

Then you need to measure your mistu piston wherever mistubishi's manual recomends measuring the skirt. I would guesse its and inch down and 180* of the wrist pin, but alot of manufacturers have differant methods.

A deck plate is something to simulate the cylinder head being bolted onto the engine when your machining it, So what you need is something with the same thickness as a head with an 87ish mm bore directly in the middle, then you bolt it down using whatever method you will use when your assemballing the engine. Including a similair head gasket and using the same lube on the bolts.

PM me if you need any thing bud.

hey thanks thats really helpful...I apreciate it. I got the pistons out today and yea the rings were shot! they were spongy as hell. Also my exaust valves are bent to hell they were hitting inside the groove on the piston...i can tell because u can see the shineyness of where it hit. its cool 2g pistons here we come.