TheSamba.com :: View topic - Connecting rods rebuild or replace...and bolts?

Sat Aug 09, 2014 9:55 am

Hi folks. I've been lurking for a while and can normally search out the answers I need, but this one I'm still not sure on.

I'm rebuilding a 1965 40hp and keeping it stock. I was planning on having a local shop rebuild the con rods but it appears new bolts for them are next to impossible to get. The old bolts really can't be reused, right? Will it be cheaper to just buy rebuilt rods? Although they seem pretty hard to find too. (The rods are 113105411A.)

It appears I'm the first person to ever open this case. Everything top to bottom is original, which was pretty cool to see.

Thanks for any insights.

Sat Aug 09, 2014 10:09 am

BlueFooted wrote: I was planning on having a local shop rebuild the con rods but it appears new bolts for them are next to impossible to get. The old bolts really can't be reused, right? Will it be cheaper to just buy rebuilt rods? Although they seem pretty hard to find too. (The rods are 113105411A.)

New bolts would be nice, but they have not been available for some time. Have not had any bolt failures myself or heard of any on other peoples 40hp engines. As for rebuilt rod sets, there are a couple places that stock them.

Sat Aug 09, 2014 10:20 am

100,000's of rebuilds have been done using the old rods with out changing the bolts, especially VW's because most VW builds are being done on the cheap.
I would say if the rods don't look burned [blue or black] and the bushing are still fairly tight go ahead and reuse them. If you change the bolt with new you should have big end rebuilt and if you do the bottom you might as well press in new bushings and hone to spec. By the time your you can probably get a set of rebuilt rods.
http://dprmachine.com.s152704.gridserver.com/products/vw-connecting-rods/

Casey

Sat Aug 09, 2014 10:47 am

Thanks guys, I'll plan on reusing the bolts then.

I need to have the case, crank, heads, and flywheel all done. So I'll see what they want to do the rods as well. The bushings are definitely shot.

Sat Aug 09, 2014 4:31 pm

You can get ARP bolts for them but they are a little pricey. They are torqued to about 32 lb-ft and the rod big end would need to be re-machined.

Sat Aug 09, 2014 5:06 pm

Don't fix what isn't broken.

Sat Aug 09, 2014 5:36 pm

satterley_sr wrote: You can get ARP bolts for them but they are a little pricey. They are torqued to about 32 lb-ft and the rod big end would need to be re-machined.
Ya, I've seen those. I think with a 40 horse I'd be better off getting rebuilt ones than buying those and paying for a rebuild. Thanks, though.

modok wrote: Don't fix what isn't broken.
Are you referring to the bolts? The rods? (Everything? :))

As far as the bolts go my concern was that, as I understand it, the metal gets stretched when they are torqued. So I thought they may be too weak to reuse. It sounds like that is generally not an issue, though (with a stocker like this).

Sun Aug 10, 2014 5:49 pm

yes, everything.

For a set of "used" rods it would be expected that the pin bushings may be worn out, and maybe the big ends will be over .0015+ out of round or not on size, so need to be cut and re-honed..........but bolts? naw. If one bolt is damaged swap it for a good used one.

The type of bolts in these rods can be re-used many times if they are not over-torqued or overheated by burning up a bearing.

Of the flat fours only the late model WBX has "stretch bolts" that may need to be replaced regularly.

Rebuilt rods and rebuilding your rods "should" be the same thing. If your are better than a average then rebuilding yours should be cheaper and better.

Mon Aug 11, 2014 9:57 am

Put your rods together and run your finger nail across the parting line. If there 8) is not a noticeable ridge there, then use the snap gauge to check them in an x pattern across the inside of the big end. If those 2 test come out OK, lay them on a machined plate to look for any twist in the rod- then if all thats good- have them replace the small end bushing and you basically have rebuilt rods.

I throw mine on a Post office scale or gram scale to even out their weight with a grinder.

Wed Aug 13, 2014 10:15 am

Thanks for the great info guys.

When I pulled these several of the rod bearings stayed on the crank. The big end of the rods seem to have a bit scoring and the crank has a fair amount as well. It looks like they must have been spinning a bit in there. This is why I figure I should have the machine shop look 'em over (or replace them). I may go ahead and go through the procedures you outlined first anyway, though.

Btw, this car had been sitting in a backyard/field for 10-15+ years before I towed it on home. So I never got a chance to hear it run.