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Sat Dec 28, 2019 9:19 am

Just wondering what thoughts are on keeping vs. replacing connecting rods.

I have the original rods, cleaned then up, and look fine. Other than replacing the bearings, what would indicate that I should get new rods? I am just rebuilding a stock 1600.

Thank you,
Mark

Sat Dec 28, 2019 9:43 am

There's also the crank/rod side play...

If everything looks good, no reason not to re-use them.

Now, stock VW balance specifications are a bit on the loose side. I would weigh them and see how close they are to each other. If they are way off, then getting a decent set already balanced might be easier than trying to balance the ones you have.

Sat Dec 28, 2019 9:50 am

So glutamodo ... the spec i have is about 592-600 grams (for gray ones).
I do not have a scale for that, but can get one. Thank you.

Sat Dec 28, 2019 9:55 am

Is the big end round?
Is the small end sloppy?
Both can be fixed at an automotive machine shop.

Sat Dec 28, 2019 9:57 am

Dougy... they were all taken off by PO... so I can't tell.

Sat Dec 28, 2019 10:12 am

Money well spent to get a professional opinion.

Sat Dec 28, 2019 10:13 am

Balance is good. I've even gone as far as strapping a piston down to a table, so I could use its pin to support a connecting rod to measure the weight of the "big end" of connecting rods which would then rest on a scale placed adjacent, . I prefer to get within a gram or so if I can, but when rods are way off from each other, that often entails a lot of time with a grinder or disc sander.

Sat Dec 28, 2019 10:23 am

Ya the spec said no more than 5 grams difference in weight between each of them.

VW Jimbo.. I do have a machine shop guy I use to get opinion.

Sat Dec 28, 2019 10:24 am

markeaton wrote: Ya the spec said no more than 5 grams difference in weight between each of them.

VW Jimbo.. I do have a machine shop guy I use to get opinion.

What did he say?

Sat Dec 28, 2019 10:28 am

I did not bring to him... I was saying it might make since to have him take a peek to see if I should keep or spring for new rods.

I'm not opposed to buying new rods, just wondering if it makes sense to keep the original.

Sat Dec 28, 2019 10:51 am

check the wristpin clearance...should be 1/2 a thousandth which is pretty much you can push it through with a little resistance but no play...dont remember what the wear limit is offhand....if you slide 3 rods onto a wristpin you can compare the distance between the big ends and see if one is bent...rod nuts that have been previously peened into the rod slot need to be replaced(not with something chinese) or the burr sanded off with 320 paper on a piece of glass...unfortunately the cost of PROPERLY rebushing and resizing a connecting rod exceeds the cost of new ones from C.B. or scat...so its kinda use them as is or throw them away....the original rods were really high quality when new but remember yours have had the hell beaten out of them for 50 years

Sat Dec 28, 2019 11:01 am

Thanks volksworld...... regarding the costs of a refub vs. new is correct.
I bought my last ones from CB and had no issues. I am going to play around and make a final decision.

Sat Dec 28, 2019 11:07 am

Just checked all 4 for wristpin clearance and 3 were 0.861 and one was 0.858.

So that checks out per Bentley Specs.

Sat Dec 28, 2019 11:28 am

markeaton wrote: Thanks volksworld...... regarding the costs of a refub vs. new is correct.
I bought my last ones from CB and had no issues.

When I rebuilt my own 1600cc engine three years ago, the machine shop which did my case and heads told me to but new connecting rods rather than have my old rods re-done. I got #1254 from CB Performance, these are still $95 like 3 years ago.
https://www.cbperformance.com/searchresults.asp?Search=1254&Submit=

Sat Dec 28, 2019 11:38 am

Hi Cusser.... those are the ones I used on a prior rebuild. Excellent. Called David at CB yesterday and those are not in stock and don't expect for months. So I either buy the $259 ones or see if my originals are worth it.

Like I mentioned I am not opposed to buying new ones, but the rods I have seem okay. Although upon closer inspection since I posted this morning, I am noticing some marred edges and such.

Sat Dec 28, 2019 11:41 am

First the good news, VW rods are heavy duty and they can be rebuilt more than once. What does this mean? It means changing the bushing on small end and reaming to size. It means checking the big end for wear, it will be out of round.
To repair this properly you’d remove the studs and machine some material off the parting line of cap and rod then put it back together and Ream to size. But before any of this you’d check for twist and for that you need a fixture and yes rods can be straightened. So finally after all that you’d weigh them and I’d shoot for a tenth of a gram which is overkill but not hard to achieve with the right equipment. Really good machinist will also balance big end and small end too. Ideally you’d shot peen or at least clean them spotless too. How much labor is involved here? To do it right its more than chinese replacement set. The chinese sets are usually balanced and a high level of fit and finish. I like German though.

Roy at Mofoco still rebuilds German rods.

Sat Dec 28, 2019 11:47 am

markeaton wrote: Hi Cusser.... those are the ones I used on a prior rebuild. Excellent. Called David at CB yesterday and those are not in stock and don't expect for months. So I either buy the $259 ones or see if my originals are worth it.

Three years ago the machine shop recommended the CB rods because it would cost me the same to rebuild mine, so I did. I have had my own rods rebuilt in the past for my 1835cc engine and they were fine.

Sat Dec 28, 2019 12:01 pm

From what I’ve seen good machine shops and competent machinists are becoming rare. Yes they are quick to recommend buying chinese. Give Roy a call and a chance before you surrender to the chinese :D

Sat Dec 28, 2019 12:03 pm

Zundfolge1432 wrote: From what I’ve seen good machine shops and competent machinists are becoming rare. Yes they are quick to recommend buying chinese. Give Roy a call and a chance before you surrender to the chinese :D

I've been pleased with my rebuilt transmission from Roy at MoFoCo. I'd deal with them again.

Sat Dec 28, 2019 12:10 pm

Thanks for the feedback. And yes, part of my wanting to use mine again, is they are true German and not a cheap knock off.

I will contact Roy. Thanks for the tip... but I might call my guy (maybe), as he does not like VW and might point me to a cheaper brand.

Having said all of this, does anyone sell German? Does CB sell Chinese?

Thank you,
Mark