I have a 5hp briggs Flathead i/c std bore and i wanna know what kinda piston will fit my arc 4.425 connecting rod. I think it has a wiesco piston on it but the rings are shot, it smokes like crazy! Can somebody please help me. I bought it not knowing that it was a 4.425 length, i thought it was a stock length connecting rod. I attached the listing photos.
4.425 connecting rod
- Thread starter Tennessee
- Start date
It could also be that the bore is "shot" (worn O/S, tapered, out-of-round, etc.) If any of those conditions exist (just) putting in new rings will not do anything to curtail the smoking- you would need to rebore it O/S and install a matching O/S piston/ring set. You should take precise bore measurements and compare that with published Briggs "reject" specs...
Michael
Michael
Please take the advice given above. @creia is absolutely correct. if the cylinder bore is tapered, out of round or worn beyond specs, you are wasting your time replacing parts. If you don't have the tools to measure it, take it to someone who does.
It looks like some good hot rod parts were installed in it. Build it strong again.
It looks like some good hot rod parts were installed in it. Build it strong again.
Custom speed.at list seems to have vanished so I can’t directly give you a list of exact pistons for a 4.425 rod. It seems there are a few arc 4.425 rods that use a .565 compression height. I (think) the stock bore is 2.562.. The rod should have a part # type the part number into arc and it will tell you a typical application. once you figure out what rod just figure out the bore size. The piston isn’t stampped on top? Even my 1986 standard bore wiseco is stampped. I highly doubt it’s one of those luna cranks I keep seeing on the forums.
Charge your phone, @Thepaetsguy
I’m not sure why i had trouble finding this earlier.. it doesn’t list the 4.425 rod but could be helpful for stock length and 4.500 rods
https://www.customspeed.at/webadmin/download/content_downloads/Karting.pdf
https://www.customspeed.at/webadmin/download/content_downloads/Karting.pdf
I don’t understand why wiseco can’t make a run of standard bore basic‘s and sell them to people like me who still want them..
And as for the briggs 5hp being 2.562 bore atc300 pistons from wiseco 12to1 comp are like $200.. I can’t figure out in my head if the ATC300 piston would be a few mm sloppy in the bore or if the bore would need honed so the atc Piston would drop in..
Then does the wristpin fit ect.. Evinrude domed outboard pistons are also 2.562 there are a few pistons that are so close in mm to a briggs 5hp stocker.
And as for the briggs 5hp being 2.562 bore atc300 pistons from wiseco 12to1 comp are like $200.. I can’t figure out in my head if the ATC300 piston would be a few mm sloppy in the bore or if the bore would need honed so the atc Piston would drop in..
Then does the wristpin fit ect.. Evinrude domed outboard pistons are also 2.562 there are a few pistons that are so close in mm to a briggs 5hp stocker.
I don‘t understand why my brain wants to figure out if an ATC 185 piston that’s 65mm will fit a 2.562 65.088mm bore. With the many billet rod length choices available It would be down to the wrisptpin from an arc rod working in this piston. How far it sets in the hole or can it be milled down if there’s a bit of pop up.
.80 and .140 over for the 2008 not sure if there charging through the roof for shipping to make that cost $100 https://cometkartsales.com/Wiseco-Briggs-P-Series-1997-2008-2009-P-Series.html
