TheSamba.com :: View topic - 1600 rebuild. Do people ever reuse pistons and cylinders?

Sun Mar 03, 2019 12:22 pm

I was checking out the pistons and cylinders off of my single port motor today. The cylinders have no score marks whatsoever and the Pistons look really good. I took them to my buddy for him to check them out and he said they looked really good also....he would just hone them and reuse them.
Then I told him a new set of pistons and cylinders were only about $120..
He said “$120 for NEW pistons and cylinders!!!??”
Hell, buy a new set then don’t reuse these then!
It seems like cheap insurance but many new parts aren’t as good as they used to be. Most of the internals look to be stock. Stock crank and stock cam.
The valves in the heads were TRW? I think.

Sun Mar 03, 2019 12:25 pm

You can hone and get new rings but I wouldn't expect 60k miles put of it

Sun Mar 03, 2019 7:12 pm

Check the #1 ring land/side clearance w/ a feeler gage: if it measures .001-.0015", they're fine. If any more than .002", then shytt-kann 'em.
TRW valves were pretty common, decades ago.

Sun Mar 03, 2019 7:22 pm

I've recycled P&C's on stockish motors if the old ones were real German parts and measured OK, as mentioned ring lands and skirt collapse as well as cylinder taper and out of round play a big part in it. Not many make the grade, but the odd time there's one that's low mileage or was treated well that can live on for another round.

Sun Mar 03, 2019 7:31 pm

Vanillagurilla wrote: You can hone and get new rings but I wouldn't expect 60k miles put of it
I re-ringed a set of stock German ones and put them back in our Bay window and they have 80K on them now! You can get more that 60K in a stock engine if they measure up good.

Sun Mar 03, 2019 8:02 pm

Thanks guys! Heck for $100 I’ll just buy a new set.

Sun Mar 03, 2019 9:02 pm

67 Sunroof wrote: Thanks guys! Heck for $100 I’ll just buy a new set.

That’s what I would do...

Sun Mar 03, 2019 9:57 pm

It was commonplace long ago. When I was a teenager, the guy I helped (warshed* parts) would do turn-key 40 hoss motors for $250 bucks. Bearings, re-ring, new exhaust valves and guides, a Neway valve seat job, gasket set, rear seal and a clutch disc.. He even reused the pushrod tubes..the parts were about $75.

*warshed is the proper pronunciation of wAshed.

Mon Mar 04, 2019 1:51 am

if you can rigid hone used cylinder and it'll clean up at only .001" over size, why, it's BETTER than new IMO Even .0015 over nominal size...is pretty good IMO, maybe with a new piston.

If the skirts check out, (<.001 collapse), and ring groove side clearance is ok (<.004), then....it's good piston, but also watch the piston pins. For whatever reason I see a lot of wear on the pins in stock type-1 engines.
Might be because they don't have oil filters.

Mon Mar 04, 2019 8:19 am

67 Sunroof wrote: Thanks guys! Heck for $100 I’ll just buy a new set.

Exactly.

But, if the cylinders are good and do check out w/ a dialbore gauge, a bottle brush carbides can bring back the cross hatch finish for a new set of rings.

The cylinders can look good but maybe warped. So unless you have a dialbore gauge, you cannot see how bad they are.

I recycle them if they check out and install new rings.

Don't use hones or deglacers. You want just the cross hatch - the best tool to use is the bottle brush type carbide balls.

Mon Mar 04, 2019 8:56 am

To give yet another option, yes, I have re-installed the SAME pistons in the SAME cylinders, no hone, no re-ring, no nothin'.

They were all good, and had done about 40% of their natural life, still lots of miles to go. This was according to bore gauge measurements and ring gaps. I needed an engine quick and cheap, but it had to be dead reliable, too. I was starting new job, and needed the bus.

P/C would have been 400-500$ here by the time they came. If I'd been in your shoes, I might have done it differently.

By the way, that engine runs great. And I was happy not to have to do the break-in, one less thing to worry about.

I'd rather have the pistons with the steel inserts, rather than new stuff, I think, and I'd re-ring and re-hone the stock parts, if the ring lands are OK. I've not seen many of the AA's, though.

Mon Mar 04, 2019 4:06 pm

+1 on a bottle brush hone, check for out of round, and put them in as long as they're not worn. I use cast rings and they seat in well. I'd rather use OEG P/C most times than anything sold today...…..

Mon Mar 04, 2019 4:40 pm

10-4 on the dingleberry......rapidly stroking it inside of a pouring SafetyKleen is moo-ee bueno.

Mon Mar 04, 2019 4:47 pm

Yeah, what kind are your OG P&L?

If they are some real German KS or Mahles,
I'd take them worn to .005" before switching them to some China AA! :lol:

If what they are is some AAs,
Then sure, replace them with some aa.

But,
Dag,
Funny how people think pistons are pistons and that they either are, or are not pistons.
Like there is no variation in quality between now and BITD..

Mon Mar 04, 2019 9:28 pm

Glad I came back to check out the thread. I was about to drop money on new p/c set.
I finished tearing down the single port motor I had.
I currently have 3 motors in unknown condition:
AE dp motor
AE dp motor #2
Sp motor

Thanks to a fellow member he encouraged me to get my feet wet and split my first vw block!! I’m glad I did!
I have the Bentley, Muir, Tom Wilson’s book (awesome book btw), all bug me videos, and tore it down tonight.
First impressions for a completely novice vw owner is the cam lobes, crank journals? look good.
My buddy cleaned the 040.101.373 heads, and did a new valve job on them for free. He said they are probably the best heads he’s seen in years. (Used to do all kinds of repairs on old vw heads-tons of cracks, etc)
The #2 bearing is showing some bronzing and a small “chip” out of the bearing. Crankshaft is extremely smooth though?
Camshaft bearing had a small chip in it but cam is completely smooth too!!?
The #1 journal has a slight indentation as felt with my fingernail.
The lifters are still flat and show very little pitting.
All pistons appear to be original but the #3. It says Brazil under the skirt. :(
Not sure what else to look for? Suggestions? I read a “quick diagnosis” is to torque the case back down and shine a light through it to check for squareness and egg shaped journals?
I Called a guy in Chestertown and he said he’s done plenty of align bores on the blocks. He seemed extremely reasonable also. I would rather take the hour drive than drop it off at my local hot rod shop and have them “line bore” it.
I don’t see any signs of cracks yet. I got a large plastic tub and dropped both case halves into some phosphoric acid tonight to get all the crud off.
I’ll check for cracks tomorrow with a propane torch.
I would like to reuse the original vw crank, vw rods, and vw cam if possible.
How can I tell if I have vw pistons and jugs?? Here are some pictures. I would appreciate any feedback if something seems out of the ordinary.

Mon Mar 04, 2019 11:19 pm

Nice work :D !

-the lifters should not be flat, if you lay them back to back, they should actually rock, they're radiused.

-That's scary sludge!!

-you need to check lift on the cam, it's probably worn more than it looks.

-what's the end-play like? Could be a go/no go for the block.

-what would be most instructive is to look at the saddle behind that n°2 steel-backed bearing. Run your fingernail over it. Any ridges?

-same for n°1 bearing saddle. Those are the ones which get the most punishment.

-the oil pump tangs don't show too too much use, but check clearances, and how deep is it in mm? just curious.

-are you sure you should be doing that to that rug? Doesn't look handmade, but if it is... :cry:

Hope this helps, keep up the good work.

Mon Mar 04, 2019 11:23 pm

Per the Schadek oil pump & Brazzy cam (a Cofap, which looks almost new), we can state that at least 1 rebuild resides in it's past history.

Yes, torque the case & check it for a split # 2 main bearing web.
Pistons: look at the face (always a size, frequently a maker's mark there) & underside of the skirts & crowns for any markings/numbers - we could likely advise what she's sporting.
This particular aftermarket forging is blank underneath, but a view in this orientation will help:

For the helluvitt - a factory 36HP crown. Note the "3/55" date marking, typical of OEM pistons:

Cylinder markings (when even present) are normally cast into the shoulder, right above the mounting face. This example also sports ink stamps on the heel. YMMV:

Tue Mar 05, 2019 6:29 am

FreeBug wrote: Nice work :D !

-the lifters should not be flat, if you lay them back to back, they should actually rock, they're radiused.

-That's scary sludge!!

-you need to check lift on the cam, it's probably worn more than it looks.

-what's the end-play like? Could be a go/no go for the block.

-what would be most instructive is to look at the saddle behind that n°2 steel-backed bearing. Run your fingernail over it. Any ridges?

-same for n°1 bearing saddle. Those are the ones which get the most punishment.

-the oil pump tangs don't show too too much use, but check clearances, and how deep is it in mm? just curious.

-are you sure you should be doing that to that rug? Doesn't look handmade, but if it is... :cry:

Hope this helps, keep up the good work.

Yep, cam has cofap 25e 12 stamped on it.
Lifters are flat
No ridges on #2
Ridges on #1 (align bore needed)☹️
Oil pump Gears measure 25mm?? (I thought they were 17mm and 19mm and dp cases were 25mm later on???
Rod side clearances are .011.
Dowels on crank are not wallered out
Rug was given to me by a friend. Wifey didn’t like it so it went in the garage! Haha

Tue Mar 05, 2019 6:41 am

FeelthySanchez wrote: Per the Schadek oil pump & Brazzy cam (a Cofap, which looks almost new), we can state that at least 1 rebuild resides in it's past history.

Yes, torque the case & check it for a split # 2 main bearing web.
Pistons: look at the face (always a size, frequently a maker's mark there) & underside of the skirts & crowns for any markings/numbers - we could likely advise what she's sporting.
This particular aftermarket forging is blank underneath, but a view in this orientation will help:

For the helluvitt - a factory 36HP crown. Note the "3/55" date marking, typical of OEM pistons:

Cylinder markings (when even present) are normally cast into the shoulder, right above the mounting face. This example also sports ink stamps on the heel. YMMV:

Pistons have SP0.04 and 85.45KR? Stamped on the crown.
3 Jugs have no imprints but one has 2AG 37 341 101 302
I’ll torque the case tonight for the heck of it.
If this proves to be unusable at least it was a learning experience for me!!
I appreciate your help very much!!

Tue Mar 05, 2019 6:46 am

I’m surprised you guys didn’t pick up on the “tub of phosphoric acid soak” comment! Hahaha
It’s sitting in soapy water.
😂