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Thu Jul 11, 2013 10:56 pm

I'm looking to rebuild an engine that the PO "rebuilt." It looks like he put on a cheap JC Whitney rebuild kit and dual carbs and forgot to reinstall half the cooling tins. The thing leaks oil like a BP oil rig, mainly out of the cast aluminum valve covers I'm replacing, but also out of either the rear main seal or somewhere else. I just get the feeling he didn't have a clue of what he was doing. Fortunately he didn't run it for very long.

I was wondering if I should line bore it or how to check to see if it needs it. I'm not sure how much they normally cost or where's a good place to get it done. I live next to nowhere Colorado so I'll either have to ship it or drive it out in my 50mpg Golf Diesel if theres a place in Denver, Utah, New Mexico, Southern Wyoming or West Texas.

This is going to be a stock 1600 dp, doghouse and all daily driver, nothing special.
I suppose if it's already line bored it will depend how much meat is left on the case and whether or not I should just get a new case. i really don't want to spend $900 on a new case though if I can help it.

I'm going for a quality job for longevity, but don't want to spend where it isn't necessary.
I'll definitly get the crank either ground or new if too far gone. I've been leaning torwards a volksracer crank just for the nitrided bearing surfaces. I know, I know, that's probabaly overkill.

I was thinking of using Aircooled's race bearings. They only sell them for uncut and .020" cut cases.

Other than that I'm probably going to go for mostly stock parts, new cam and lifters, AA 85.5 hypereutectic P&Cs, Deves rings, chromoly pushrods and swivel foot adjusters. Stock DVDA and 34PICT both rebuilt. All cooling tins and thermostat and flaps.

Thu Jul 11, 2013 11:18 pm

An ok test is to take your fingernail and check for ridges on the main bearing saddles. If you can feel ridges, it probably needs an align bore

Thu Jul 11, 2013 11:21 pm

get a set of micrometers
and a dialbore guage

torque the case and measure the tunnel...(mains)

Fri Jul 12, 2013 1:38 am

In the springs we have five shops with portable VW line bore bars.
I don't even bother to do it myself, even though I could.
prices for that operation will vary from 60-120$ depending
The size of the line bore is not important, rather the condition of the case otherwise should determines if it is worth using.
If the case is too badly warped, cracked, lifter bores worn out or front/rear seal areas too out of shape then it is time to retire.

There is no shortage of good crankshafts here either, but cases are getting scarce.

And there is painters in denver, and colorado cranshaft also

Fri Jul 12, 2013 4:40 am

Most cases need a linebore.
Its not because the bearing saddles are damaged but mainly due to the case becoming warped

Fri Jul 12, 2013 6:19 am

Prior to splitting the case half's, torque the center main case nuts to 30 foot pounds and see if the crank still turns. If it does not turn, then the case is warped. Most line bored cases suffer from low oil pressure.

Fri Jul 12, 2013 7:44 am

56vwoval wrote: Prior to splitting the case half's, torque the center main case nuts to 30 foot pounds and see if the crank still turns. If it does not turn, then the case is warped. Most line bored cases suffer from low oil pressure.

Ok, why low oil pressure?

Fri Jul 12, 2013 8:05 am

56vwoval wrote: Prior to splitting the case half's, torque the center main case nuts to 30 foot pounds and see if the crank still turns. If it does not turn, then the case is warped. Most line bored cases suffer from low oil pressure.

No need for low oil pressure if it is done correctly. In my experience, most low oil pressure is from worn lifter bores.

Fri Jul 12, 2013 1:31 pm

Is the tool new or old? Does the machinist have experience? are the centering bushings in good shape. Are the cutting blades sharp? You cannot replicate what VW did at the factory and that is why VW never used or sold line bored cases, even on there refurbished engines! Do not expect full life out of a line bored case. To me to rebuild is to make new, not half new!

Fri Jul 12, 2013 4:50 pm

VW never did line bores because even as late as 1980 you could pick up a new case for around $100. A line bore was in the $50 to $80 range.
I get lots of high mileage, 60 over cases into my shop and they are usually brought in as running motors that were removed not because they were worn out, but to be stroked or have larger P&C's pistons installed.

Fri Jul 12, 2013 5:03 pm

56vwoval wrote: You cannot replicate what VW did at the factory and that is why VW never used or sold line bored cases...

Oh BS. Machine shops have all sorts of capabilities. Are the common and-getting-tired boring bars good enuff? I don't know - _maybe_ not... but this mystical VW-cultism is making me look for some boots to keep my feet clean...

Fri Jul 12, 2013 5:08 pm

56vwoval wrote: Is the tool new or old? Does the machinist have experience? are the centering bushings in good shape. Are the cutting blades sharp? You cannot replicate what VW did at the factory and that is why VW never used or sold line bored cases, even on there refurbished engines! Do not expect full life out of a line bored case. To me to rebuild is to make new, not half new!

yes, I can replicate what VW did. yes they did rebuild cases, that is what the three arrow stamp means

Fri Jul 12, 2013 5:12 pm

Why thanks guys! I'll try testing the crank, looking for ridges, I got a micrometer and all. So far I do know that the crank turns very easily with the heads off but I haven't tried retorquing first yet. The engine had suffered from overheating at least once and messed up the heads. Hopefully everything else checks out and the case isn't warped.

Fri Jul 12, 2013 7:03 pm

If lined bored too big then the engine can run hotter than a case with a smaller line bore, Gene berg had a great article explaining this, something to do with the thickness of the bearings if I remember correctly.
I also found out for my self, one case at .060 over and one at .020 over, the .060 ran warmer than the .020 with all the exact same components in it swapped from the other motor in the exact same car. It ran about 10 degrees warmer. Not terrible but it was warmer.

Mike

Fri Jul 12, 2013 7:13 pm

There is about 2 thicknesses of standard printer paper difference in thickness between each cut on the radius.
There is less than 1% increase in mass between each larger size.
A larger bearing will have a larger surface area so transfer more heat to the case.
Sooooo.... Typical VW BS.

Sat Jul 13, 2013 10:13 am

Dr OnHolliday wrote: this mystical VW-cultism is making me look for some boots to keep my feet clean...

I wish I had said that.

Sat Jul 13, 2013 10:53 am

Jimmy111 wrote: There is about 2 thicknesses of standard printer paper difference in thickness between each cut on the radius.
There is less than 1% increase in mass between each larger size.
A larger bearing will have a larger surface area so transfer more heat to the case.
Sooooo.... Typical VW BS.

Precisely. The larger the bearing, the larger the mass of aluminum, however slight, to absorb and conduct heat away from the bearing space, if that were the major factor in cooling, which it isn't. The bearing is cooled far more by the flow of oil thru the clearance than by transfer to the case. To state otherwise is to claim that passive conduction can outstrip active fluid cooling, which is an absurdity, and which also betrays ignorance of the source of heat in the bearing space in the first place, which is the shearing of the oil itself. The oil heats up directly by shear stress at the molecular level, leaves the bearing space to give up its excess heat elsewhere, and is pumped back to do it again.

Meanwhile you have expanded the area of support for the bearing, once again however slightly, by increasing its OD. Which when you are talking about your frail little magnesium cases is nothing to scoff at.

The big reason an accurate line-bore is undesirable is that it means there are fewer rebuilds left for that case. Inaccurate align-bore jobs are undesirable for reasons that would be obvious to anyone, and with so much shoddy work in this market, the fear of that may be good enough reason to stick with what you've got.

So many parrots, reading here is like a free trip to Brazil.

Sat Jul 13, 2013 12:18 pm

Rear main seal? There is a front main seal, but the rear of the crankshaft is bolted to the pulley. The grooves on the flange attached to the pulley spin the oil splash back into the crankcase. No rear seal.

How is the end play? You can really mess an engine up by running with too much; that would mean beating the crank into the case like a sledgehammer every time you release the clutch.

Take it apart and see where your oil leaks really originate.

Sat Jul 13, 2013 2:02 pm

Harleyelf wrote: Rear main seal? There is a front main seal, but the rear of the crankshaft is bolted to the pulley. The grooves on the flange attached to the pulley spin the oil splash back into the crankcase. No rear seal.

How is the end play? You can really mess an engine up by running with too much; that would mean beating the crank into the case like a sledgehammer every time you release the clutch.

Take it apart and see where your oil leaks really originate.

Sorry. I'm used to Chevy terminollogy. It could be the front main seal. The rear did spit oil but I think that was because of breathing issues due to the non existant breather system the PO set up.

I'm going to see where the leaks are coming from. Could be anything at this point although the cooler and such looks good with the doghouse off. I haven't got it out right now but I will.

Since I haven't dropped the engine I haven't checked crank end play yet. I will have it well shimmed when I redo it. I'm going to see what the PO left it at. I'll bet he didn't even measure the end play when he "rebuilt it". Now I see i have broken fins on a head. Hopefully I'll be able to mix a 113.101.375A with another 113.101.375 off another engine. The broken head is a 311.101.375. I'm not sure what the difference between a 311 and a 113 is.

Sun Jul 14, 2013 11:23 am

Jimmy111 wrote: Sooooo.... Typical VW BS.

tencentlife wrote: So many parrots, reading here is like a free trip to Brazil.

Gee sorry guys but as I stated, "If I remember correctly", which I didn't. Dug out my articles and it was a oil pressure issue, not heat with line boring too many times as some of you have stated. Give an old guy a break and maybe read all the words and not just the ones you want to see.

Mike