We stayed in Flagler Beach which is about 10 min. North of Ormond Beach which is about about 10 min north of Daytona Beach. The pic near the Intercoastal is the beginning of the Flagler and Ormond loops. Cross over plus a couple of miles then turn South to the Ormond Loop or North to the Flagler loop. 

Big hat's off to Anthony today for some very quick help. My new CB Performance alternator pulley finally arrived to day via USPS and Canada Post. The new pulley parts are just beautiful but I noticed from the get go that this CB pulley has a larger diameter than the pulley that was on there. My problem was that I needed advice on where / how to source a new belt of the correct length. It turns out that the existing belt is 840 mm and the replacement belt needs to be about 912 mm. Anthony made it easy and the local Napa will have one for me tomorrow at 8 am.  Thanks, Anthony...nice one !!

mppickett posted:

Hi David, I'm glad it's coming together. Just curious, do you have a power crank pulley or a regular size one?

Mike

Giday, Mike. I don't know much about my engine other than it was built 55,000 km ago by a fellow in Vancouver, Canada that had a good reputation. Here's a pic of the new CB Performance alt pulley just sitting on the shaft and my hand holding one half of the pulley that had gone bad. Full o.d of the new ( black pulley ) is 4 1/4" and the one I'm holding is 3 3/4"o.d. 

I don't know what a crank "power" pulley is, nor do I know the o.d. of a regular sized one. My crank pulley is shown in the second blurry pic. It is 5 3/4" o.d. 

Now  quick poll to help make a colour decision on a small plane I'm rebuilding. 5th pic is the type of plane....just a small single seat job but it needs to get painted in Military yellow or silver. Which colour do any of you like, please ? Yellow 3rd pic or silver 4th pic ? Thanks. 

 

 

Attachments

Images (5)
David Stroud IM Roadster D posted:
Giday, Mike. I don't know much about my engine other than it was built 55,000 km ago by a fellow in Vancouver, Canada that had a good reputation. Here's a pic of the new CB Performance alt pulley just sitting on the shaft and my hand holding one half of the pulley that had gone bad. Full o.d of the new ( black pulley ) is 4 1/4" and the one I'm holding is 3 3/4"o.d. 

I don't know what a crank "power" pulley is, nor do I know the o.d. of a regular sized one. My crank pulley is shown in the second blurry pic. It is 5 3/4" o.d. 

Now  quick poll to help make a colour decision on a small plane I'm rebuilding. 5th pic is the type of plane....just a small single seat job but it needs to get painted in Military yellow or silver. Which colour do any of you like, please ? Yellow 3rd pic or silver 4th pic ? Thanks. 

 

 

Hi David, The normal size of the alternator pulley is 4 1/4" so your bad one may have been an undersized pulley. Your crank pulley is a "power pulley." Normal size crank pulleys are around 6 3/4" and folks often switch to a smaller pulley to reduce the speed of the alt/fan to save power at high rpms.

Regarding paint color, I like the look of the silver with yellow trim (4th pic). The silver helps to set off the shape of the cockpit. Very nice looking plane!

Thanks,

Mike

David Stroud IM Roadster D posted:

Giday, Mike. I don't know much about my engine other than it was built 55,000 km ago by a fellow in Vancouver, Canada that had a good reputation.

 I believe Darren Krewenchuck built the engine for Ron Leonard.

Last edited by Stan Galat
Stan Galat posted:
David Stroud IM Roadster D posted:

Giday, Mike. I don't know much about my engine other than it was built 55,000 km ago by a fellow in Vancouver, Canada that had a good reputation.

 I believe Darren Krewenchuck built the engine for Ron Leonard.

Correct. And it sure would be nice to see what's inside....but no I won't until necessary.

David, your old pulley ratio is 1.53:1, you new one is 1.35:1. The new ratio with your larger pulley is 13% SLOWER than before. You might want to keep an eye on your head temps.

Stock fan ratio is 1.59:1, the stock fan is the fastest and flows the most air. Your new ratio is almost 18% slower than stock. I'd pay attention to oil temps. And buy a CHT gauge.

Or, the best solution? Buy a stock size(6.75") degree pulley and another even longer belt. Take the crank pulley off first to see if it's the stock threaded type or sand seal.

Last edited by DannyP
DannyP posted:

David, your old pulley ratio is 1.53:1, you new one is 1.35:1. The new ratio with your larger pulley is 13% SLOWER than before. You might want to keep an eye on your head temps.

Stock fan ratio is 1.59:1, the stock fan is the fastest and flows the most air. Your new ratio is almost 18% slower than stock. I'd pay attention to oil temps. And buy a CHT gauge.

Or, the best solution? Buy a stock size(6.75") degree pulley and another even longer belt. Take the crank pulley off first to see if it's the stock threaded type or sand seal.

I'll look at the crank pulley situation tomorrow. What are the implications of stock threaded type or sand seal ? 

Ray, I'm sorry but a lot of street cars have sand seals. David, remove the crank pulley(30mm socket, should be). If it has what looks like threads on it, it is standard. If the hub is smooth and there is an oil seal, it's a sand seal pulley.

I wish, that for all time we could put the "sand seal is only for sand" thing to bed for good. Every engine designed in the last 80 years (a Type 1 VW doesn't make the cut) has an oil seal on both ends of the crankshaft. There is absolutely no reason not rot run one on the pulley end.

None.

I take it "there is absolutely no reason NOT to run one on the pulley end" 

Great to learn something today

Last edited by IaM-Ray

Stan, we need to first get rid of all the semi-hemi low compression Berg BS. Then we'll have made some progress.

I checked with CB Performance today because they sell two non stock pulleys. PN 1931 which is what I bought for about $75 and PN 1912 for about $45 and this one looks to be a smaller diameter on the website. In fact they are the same diameter at 4.25 ", just that the last one is made in Taiwan and the better one is made by CB Performance. 

So now I'm wondering why would they make one that would turn the cooling fan slower than stock ? 

David Stroud IM Roadster D posted:

I checked with CB Performance today because they sell two non stock pulleys. PN 1931 which is what I bought for about $75 and PN 1912 for about $45 and this one looks to be a smaller diameter on the website. In fact they are the same diameter at 4.25 ", just that the last one is made in Taiwan and the better one is made by CB Performance. 

So now I'm wondering why would they make one that would turn the cooling fan slower than stock ? 

My understanding  is that it’s the other way around. There is the stock diameter VW generator/alternator pulley and then they started using the Porsche 356 diameter pulley which is smaller to get the fan to turn faster.

I have a JayCee crank pulley.  It is 7", not 6.75".  I thought it would be good to get a little more cooling.

I did sell my semi-hemi heads when I went from 1776 to 2110.  My compression went from about 6.9 to 9.

Think of this like a multi-speed bicycle. A bigger ring up front and a smaller gear out back means you go faster, but it takes more power to push the gear.

The crank pulley is like the big ring on the bike. A smaller pulley means the fan turns more slowly. A larger pulley means it turns faster.

The fan/alternator pulley is like the gears in the cassette on the bicycle's rear wheel. A smaller pulley means the fan spins faster, a bigger one means it turns more slowly.

The only way to overdrive the VW fan is to put a stock diameter pulley on the crank, and the smaller 356 fan pulley on the alternator. I wouldn't do this without a welded and balanced fan. Even then, I wouldn't spin my engine over 6500 RPM or so.

Most people want no more fan speed than they absolutely need. Spinning the fan more slowly means there is more power available for motive power. That's why this arrangement is called a "power pulley". There are many different combinations to play with. 

Last edited by Stan Galat

Good Morning to some and Good Afternoon to others.

this pulley thing is simple...stock gen/alternator is 4 1/4" OD,  but found some early pulleys measured 4 3/16" OD

CB performance billet pulley measures 4 1/4" OD

356 porsche is 3 3/4" OD.

stock steel crank pulley [with grooves and no seal] measures 6 7/8" OD

JC measures 7" OD with or without grooves for a seal.

Scat alum pulley measures 6 3/4" OD either with grooves or without for seal.

aftermarket "power pulleys" measure 5 1/4" and were designed to clear dry sump pumps and slow the fan speed and resistance at higher rpm's.

The popular trick of the days past was to use the 356 pulley to speed up the fan speed at lower rpm's. of course it also increased fan speed overall but the negative point was the fans would come apart.

Overall I have ran all these combo's and they were suited for each situation. there's not one correct application unless it's 100% stock. Same logic goes for the seal no seal topic. what ever works for your application. several people feel they need a seal at the front pulley to eliminate oil leaks. Most cases your oil leaks are due to TOO Much Crankcase pressure.

Hope everyone is doing well with all the things going on. no better time to work on that classic.......just think of it as a job and when you walk out to garage for 8 hours you won't hear your other half ask " what are you doing" every 10 minutes

Stan Galat posted:

Think of this like a multi-speed bicycle. A bigger ring up front and a smaller gear out back means you go faster, but it takes more power to push the gear.

The crank pulley is like the big ring on the bike. A smaller pulley means the fan turns more slowly. A larger pulley means it turns faster.

The fan/alternator pulley is like the gears in the cassette on the bicycle's rear wheel. A smaller pulley means the fan spins faster, a bigger one means it turns more slowly.

The only way to overdrive the VW fan is to put a stock diameter pulley on the crank, and the smaller 356 fan pulley on the alternator. I wouldn't do this without a welded and balanced fan. Even then, I wouldn't spin my engine over 6500 RPM or so.

Most people want no more fan speed than they absolutely need. Spinning the fan more slowly means there is more power available for motive power. That's why this arrangement is called a "power pulley". There are many different combinations to play with. 

Absolutely; I later switched to a welded and balanced fan with my 356 pulley. VS shipped them with the 356 pulleys but with regular stock fans.

David, here are the two possibilities for the pulley hub. Good example of proper "threading" or oil grooves. Also a "no machine" or "slip-in" sand seal.20190629_141049

Attachments

Images (1)

Add Reply

Post Content
×
×
×
×
Link copied to your clipboard.
×
×