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Tue Nov 29, 2016 3:03 pm

johnny d wrote: grailoc wrote: johnny d wrote: Hi Gents,
did someone actually use those ISP OT Pulleys?

if so, can someone tell me if these work or not?

I have one but still have not the chance to get the engine running, and i know wondering about the measures of the rear. All OG VW-Pullys are 49,90mm,

Just measured my OG pulley and had 49.9mm exactly.

your OG OT Pulley or OG VW Pulley?

OG VW Pulley :-)
I got the same measurement what you had on the picture above

Tue Nov 29, 2016 7:39 pm

johnny d wrote: grailoc wrote: johnny d wrote: Hi Gents,
did someone actually use those ISP OT Pulleys?

if so, can someone tell me if these work or not?

I have one but still have not the chance to get the engine running, and i know wondering about the measures of the rear. All OG VW-Pullys are 49,90mm,

Just measured my OG pulley and had 49.9mm exactly.

your OG OT Pulley or OG VW Pulley?

I find that a curious and somewhat uninformed question! (No offense intended - few of us have direct experience with these, I guess.)

...From the first days of Porsche, they used the same crankshaft bore as VW, and every aspect of the crankshaft bore, including both the pulley end and the flywheel end, were identical for both companies engines. They remained the same until the advent of the three-piece crankcase for Porsche when Porsche bumped up the bore by a quarter millimeter, presumably to prevent the use of the VW bearing in their new case instead of the new bronze backed bearings introduced at the same time. (That didn't entirely work, though, because some aftermarket companies made a VW style bearing in the Porsche size! This means that you COULD have align-bored your VW to one quarter mm oversize and run EITHER a standard Porsche bearing OR an aftermarket bearing and I have seen many cases, both VW and Porsche, that had this done to them...

So, what I'm saying is; they're the same.

I also went and just measured two of my four "OG" OT pulleys - the two that aren't presently mounted on an engine! - and they were 49.92 and 49.91mm, respectively.

The pulley bore in the case, by the way, starts at EXACTLY the same bore size as the #4 main bearing's outside diameter because the two bores are cut by the same cutter at the same time. (IE: the pulley bore is nominally 50mm.)

If the ISP West product is indeed 49.3 as the image shows, they would likely leak, I would think (!!) and they should in any event fix this manufacturing oversight.

Now, they ARE aluminum and aluminum has a different coefficient of expansion than steel (or maybe they're iron?) does, so they might need to be a tiny bit smaller to ensure they don't rub when hot, but I seriously doubt that they need 0.6mm for that! ...That's 0.3 per side, of course, but still...

Wed Nov 30, 2016 5:19 am

so....

Does anyone else have an iSP pulley to measure.??? I was about to buy one but now I am not so sure...

Thu Dec 01, 2016 3:04 pm

rtroy wrote: johnny d wrote: grailoc wrote: johnny d wrote: Hi Gents,
did someone actually use those ISP OT Pulleys?

if so, can someone tell me if these work or not?

I have one but still have not the chance to get the engine running, and i know wondering about the measures of the rear. All OG VW-Pullys are 49,90mm,

Just measured my OG pulley and had 49.9mm exactly.

your OG OT Pulley or OG VW Pulley?

I find that a curious and somewhat uninformed question! (No offense intended - few of us have direct experience with these, I guess.)

...From the first days of Porsche, they used the same crankshaft bore as VW, and every aspect of the crankshaft bore, including both the pulley end and the flywheel end, were identical for both companies engines. They remained the same until the advent of the three-piece crankcase for Porsche when Porsche bumped up the bore by a quarter millimeter, presumably to prevent the use of the VW bearing in their new case instead of the new bronze backed bearings introduced at the same time. (That didn't entirely work, though, because some aftermarket companies made a VW style bearing in the Porsche size! This means that you COULD have align-bored your VW to one quarter mm oversize and run EITHER a standard Porsche bearing OR an aftermarket bearing and I have seen many cases, both VW and Porsche, that had this done to them...

So, what I'm saying is; they're the same.

I also went and just measured two of my four "OG" OT pulleys - the two that aren't presently mounted on an engine! - and they were 49.92 and 49.91mm, respectively.

The pulley bore in the case, by the way, starts at EXACTLY the same bore size as the #4 main bearing's outside diameter because the two bores are cut by the same cutter at the same time. (IE: the pulley bore is nominally 50mm.)

If the ISP West product is indeed 49.3 as the image shows, they would likely leak, I would think (!!) and they should in any event fix this manufacturing oversight.

Now, they ARE aluminum and aluminum has a different coefficient of expansion than steel (or maybe they're iron?) does, so they might need to be a tiny bit smaller to ensure they don't rub when hot, but I seriously doubt that they need 0.6mm for that! ...That's 0.3 per side, of course, but still...
thats what isp wrote me back:
Hi,

It is a very small difference and it will not cause an oil leak.

Thank you,
Alex Pegado
ISP West
310 637 2100

Fri Dec 02, 2016 10:06 am

I think if there is not positive pressure into the engine case then there should not be any issue with pulley oil leak.

A breathing box might help preventing this.

Fri Dec 02, 2016 10:12 pm

johnny d wrote: rtroy wrote: johnny d wrote: grailoc wrote: johnny d wrote: Hi Gents,
did someone actually use those ISP OT Pulleys?

if so, can someone tell me if these work or not?

I have one but still have not the chance to get the engine running, and i know wondering about the measures of the rear. All OG VW-Pullys are 49,90mm,

Just measured my OG pulley and had 49.9mm exactly.

your OG OT Pulley or OG VW Pulley?

I find that a curious and somewhat uninformed question! (No offense intended - few of us have direct experience with these, I guess.)

...From the first days of Porsche, they used the same crankshaft bore as VW, and every aspect of the crankshaft bore, including both the pulley end and the flywheel end, were identical for both companies engines. They remained the same until the advent of the three-piece crankcase for Porsche when Porsche bumped up the bore by a quarter millimeter, presumably to prevent the use of the VW bearing in their new case instead of the new bronze backed bearings introduced at the same time. (That didn't entirely work, though, because some aftermarket companies made a VW style bearing in the Porsche size! This means that you COULD have align-bored your VW to one quarter mm oversize and run EITHER a standard Porsche bearing OR an aftermarket bearing and I have seen many cases, both VW and Porsche, that had this done to them...

So, what I'm saying is; they're the same.

I also went and just measured two of my four "OG" OT pulleys - the two that aren't presently mounted on an engine! - and they were 49.92 and 49.91mm, respectively.

The pulley bore in the case, by the way, starts at EXACTLY the same bore size as the #4 main bearing's outside diameter because the two bores are cut by the same cutter at the same time. (IE: the pulley bore is nominally 50mm.)

If the ISP West product is indeed 49.3 as the image shows, they would likely leak, I would think (!!) and they should in any event fix this manufacturing oversight.

Now, they ARE aluminum and aluminum has a different coefficient of expansion than steel (or maybe they're iron?) does, so they might need to be a tiny bit smaller to ensure they don't rub when hot, but I seriously doubt that they need 0.6mm for that! ...That's 0.3 per side, of course, but still...
thats what isp wrote me back:
Hi,

It is a very small difference and it will not cause an oil leak.

Thank you,
Alex Pegado
ISP West
310 637 2100

I don't think 23 thou is "very small" but what do I know.

Thu Dec 22, 2016 8:38 am

What size belts are ya'll running with these pulley's? I'm using the stock generator pulley on my 36HP case and I've tried several but all of them are too long.

Sat Dec 24, 2016 10:25 am

So here's a couple of pictures of my belt trials...

zero shims between the pulley

Sun Dec 25, 2016 8:01 am

Use a piece of rope and then measure the rope

Sun Dec 25, 2016 8:37 am

Go with an 887 belt

http://www.vbeltsupply.com/spz887-1.html

Mon Dec 26, 2016 9:17 pm

I ordered a 10x888, we'll see if that one works.

Thu Dec 29, 2016 4:31 pm

sorry, i can´t help you out here.. i ordered ten different belts until i found this one, that works the best..

Thu Dec 29, 2016 10:06 pm

johnny d - Did you forget to post the belt size you used?

Mon Jan 02, 2017 10:04 am

IDK why anyone would have trouble with the belt size; if you run the stock 36hp gen pulley, the standard belt should fit fine. Here's an example with a genuine OT pulley, 36hp gen pulley circa 1959, and a stock belt:

Remember, the OT pulley is the same size as the standard 36hp pulley; while it will take a wider belt, a wider belt is not required.

If you have a problem, it's probably because the repro isn't that faithful. . .

Sun Mar 05, 2017 11:03 pm

jdub63 wrote: So here's a couple of pictures of my belt trials...

jdub63

You have the correct 36hp generator pulley as I can tell from your photo that 1 half has a "wider" lip. Not sure if rtroy is aware that he is not running a 36hp generator pulley but a much later one. Probably a 40hp which explains why his fan belt fits and yours doesn't. You can see on my engine, I'm running a 10X900 Continental belt BUT with a Denzel crankshaft pulley. See photo below.

Have you tried running a fan belt WITHOUT the "cog" type serrations? That may help. Good luck, Mr. Okrasa 8)

Sat Jul 29, 2017 10:29 pm

Anything new from Anthony on the oil slingers section being too small. I've now heard from multiple people that they cause oil leaks at the pulley.

Fri Aug 25, 2017 11:51 am

Mr.Ragtop wrote: Anything new from Anthony on the oil slingers section being too small. I've now heard from multiple people that they cause oil leaks at the pulley.

Not heared anything, but mine is also leaking.. :(

Fri Aug 25, 2017 4:36 pm

leaked like a sieve on an okrasa engine I worked on...yanked it off for an original pulley, much better!!

they don't even look that cool :shock:

Tue Aug 29, 2017 12:30 pm

I just received (2) OT crankshaft pulleys and by reading this thread, I think I should send them back? The top pulley is the
one from ISP and the bottom is a stock pulley. The measurements are way off!..........UGH :cry: Thoughts anybody?

Tue Sep 26, 2017 10:13 pm

I sand blasted mine and then had it welded up. I'll be lathing it back down to the correct 49.9mm and then cutting the "sling grooves" back in. Should be good to go then