can we use alum piston in alum COOL BORE engine. old chromed piston/stock is scored pretty badly

A SIMPLE PLAN

A SIMPLE PLAN

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the motor will never be NHRA condender, which wud give better service. sanded stock BRIGGS Chrome piston w/ sanded skirt to work down some of the scratches in the piston. did that... still got scratches; or put in a new stens alum piston (NOT FOR OVER 10% ethanol... reads somewhere in description as... all alum piston? )

cyl is scored too, honed it out best i cld. read something abt Chevy Vega's and alum pistons in alum blocks... didnt do very well, engine longevity wise. shd i stay with scored stock piston that is chrome and BRIGGS or go with new alum Stens piston that i have in alum block? how critical is the alum piston in the alum bore problem/issue? which way to go... stock chrome scored piston or new alum piston?
 
An aluminum piston in an aluminum bore (with no coatings involved) will not end well.
Get the right piston for the cylinder.
Either use a coated piston or install a steel sleeve and then you can run an uncoated piston.


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Alum bore n alum piston won't end well, sigh. Figures... Already got alum piston thinking a piston is a piston is a piston. New is better than old dinged up piston
 
Don't try to build an aluminum bore flathead with an R3 OR Burris chromed piston.
Sure, with the older design barrel shaped pistons, they worked just fine, but with the new tapered skirt pistons you WILL have problems. The piston rocks @ TDC and will flat wipe the cylinder out where the bottom of the skirt touches the cylinder (front and back) especially on the thrust side. 1, maybe 2 races later and you'll be reboring it.
If the block is a good one, have it sleeved special undersized hardened sleeve that has better wear characteristic and sealing (less porosity) that can be align bored perfectly at standard bore.

Your saying then to use the old full skirt pistons.
I'm bout to build one and have old stock and I think a couple hortsman chrome pistons maybe a wiseco. Any thing but the r3 ?
  • IF it's just a backyard project, then sure, use the old R2 and prior pistons.
For a WKA type build, only use the R3 piston -- the ring package itself is worth the difference.
If you have an old stock Wiseco chromed piston, then you can use it. You can also have the unchromed old stock Wiseco pistons coated (skirts & dome.) I do not recommend this with the new style Wiseco.

Do not use the R3 piston (coated or not) in an aluminum bore -- it will not last. (too much rock)





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donno? took everything i had to copy and paste most of what i wanted to know off the page as it copied EVERYTHING that had to try to delete to get to the meat of the issue . alum pistons in alum bores are not good for longevity, apparently??? who wud have known? its a piston and a cyl? put a wood piston in it ... longevity might suffer but if it fits... it ships USPS flat rate box ;)
 
I was being facetious. Those are my words you copied.
There's nothing wrong with aluminum pistons in aluminum bores...but the piston had better have a coating on it and not be of the short skirt R3 style.
A wood piston would be short lived as well -- just in case you are tempted to try it. :)
 
A SIMPLE PLAN said:
the motor will never be NHRA condender, which wud give better service. sanded stock BRIGGS Chrome piston w/ sanded skirt to work down some of the scratches in the piston. did that... still got scratches; or put in a new stens alum piston (NOT FOR OVER 10% ethanol... reads somewhere in description as... all alum piston? )

cyl is scored too, honed it out best i cld. read something abt Chevy Vega's and alum pistons in alum blocks... didnt do very well, engine longevity wise. shd i stay with scored stock piston that is chrome and BRIGGS or go with new alum Stens piston that i have in alum block? how critical is the alum piston in the alum bore problem/issue? which way to go... stock chrome scored piston or new alum piston?
Click to expand...
Chrome pistons on cool bore blocks only. Don't waste your time installing an unchromed piston in a cool bore. If you don't have another piston and if you're on a tight budget, look around a few older junk push mowers with 3.5 HP Briggs engines on them. Those have the cool bore block and the chrome piston you need for your 5 HP block and most will still be in good shape.
 
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