7 replies to this topic

[TehMarchant]

Hi all,

I am gathering parts for an engine build.

I was just curious if these rods are the right size.


Dimensions
Center to center length: 146.05mm
Big end diameter: 45mm
Small end diameter: 20.63mm

Sorry they supply the measurements in MM

I’m using p21253 pistons, which are interference fit

Cheers all

[mini13]

what are you putting them in?

 

those dimensions look to be for a 1275 rod,

[TehMarchant]

Sorry should have specified. It’s a 1275 a+ Mostly concerned about the wrist pin size

[mini13]

ok you should be good then,

 

the wrist pins are IIRC 812 thou (0.812inches or 20.625mm)  are these normal rods or somthing aftermarket? ie not press fit pins.

[TehMarchant]

You e been so helpful, Yes they’re aftermarket

https://www.ebay.co....4.m46890.l49292

Hoping they’re lighter than standard and should take abuse better

[nicklouse]

Mmm don’t look like they will work with your pistons of choice. As they seem to have a bush fitted.

[TehMarchant]

Mmm don’t look like they will work with your pistons of choice. As they seem to have a bush fitted.

That’s kinda what confused me about their image. Could just be a generic image though

[mini13]

Ah!

 

yeah they will be sliding fit, also I did heas somthing about the web being larg enough to contact the bottom of the  bore especially on standard bores.

 

I have used sliding fit rods before ( also converted std rods with a reamer to sliding fit to maks assy/disassy easier) with PTFE pin buttons ( auminium has also been done), bit you'd have to get those made up specifically to your pins as the pins vary between piston manufacturer.

 

I will say although H beam rods are nice, they really arnt needed, the standard rods are very robust, and jsut swapping to arp rod bolts would give a pretty bullet proof bottom end.