I Was at Gene Berg today and.......................

[65bug]

Guys,
I was at Gene Berg today and puchased my new blueprinted full flow oil pump, full flow kit and racing forged gland nut and blanchard washer. While speaking with them I asked all sorts of questions.
I plan on running 78x94 for a displacement of 2165. I was told that the 94 cylinder walls ARE THINNER then the 90.5 cylinder walls! I almost asked him to get two out so we could measure them right there on the spot. He said you get blow by very quickly and that a noticable power difference would be very minimal once this blow by starts getting bad.
Before I cut my Jeff Denham heads to 94's and my brand new 650.00 case with all the machining can anyone tell me if this is right? Are the cylinder walls thinner on the 94's? I feel from 90.5 to 94 the horsepower increase should be substantial.
Any help would be greatly appreciated!

Thank you

[Jake Raby]

Yes they are thinner....

Looks like their way of thinking still hasn't changed.

Many, many people are running 94mm bored engines with no issues on the street everyday in todays modern world.

So what if they are thinner...... I have seen engines with 65,000 miles that were driven very hard and the cylinders were not warped. The one engine that sticks in my mind was in a speedster replica and they are known for lacking cooling efficiency due to the decklid design.

Not many people these days are hardcore enough to drive these cars everyday for 100K miles anyway.... Some will see 10K miles in 20 years!

Go to Cal look.com and look for some posts by mark herbert on the subject.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[Terry Cloyd]

[Alan_U]

Cut the heads to 94mm!! I have yet heard lately of anyone having serious blowby on 94mm. Yup there thinner but I dont have blowby issues or pretty well everyone else running 94mm.

That statement would mean everyone with 94mm are having serious problems with loss of Horsepower. That means majority of all stroker engines who are trying to maximize displacement with large barrels with their "X size" stroker crank is having warped cylinders.

I wouldn't hesitate for one second to go 94mm's. Dont worry about warpage since it hasn't been an issue for years.
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11.92sec pump gas true daily driver. Who says it cant be done.

No more time for VW's.......

[Jake Raby]

Next thing you know we'll start hearing the "6.6:1 and no more than 7.3:1 or your engine will detonate" crap again.......

I haven't built a single damn engine all year with less than 9:1 CR! Hell that was in a BUS!

"Bump it up and hear it thump!"

If it scatters or leaks then take it apart and fix it, hell it'll give you something to do! There is no such thing as too much wrench time!

ell, come to thin of it I haven't built an engine all year with less than a 94mm bore.....

Wonder what they would say about my 105.7mm cylinders for the 3.0???? Yeah, its a street car too!
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[Bruce]

[Dave]

I believe these to be true representations of the cylinder thickness, measured at the top of the cylinder.
These measurements were done at MY Home, with MY calipers, on NEW cylinders. This is probably *NOT* accurate, to within the .00001" or anything, but should be close. This is also *MY* opinion, *MY* opinion alone, and *IS NOT* the opinion of the place I work, or anyone else I work with. Just something I did to satisfy my own personal curiosity-

Cylinder manufacturer/ Size/ thickness (in inches)

Cofap 85.5mm .160
Cima 87mm .130
Cima 88mm machine-in .175
Cima 90.5mm .145
Cima 92mm .115
Cima 94mm .130


If my measurements were correct, then there is .015" difference between the Cima/Mahle 90.5mm and the Cima/mahle 94mm barrels. To be fair, I have seen the thinnest barrels (the Cima/Mahle 92mm) hold up admirably, as long as you aren't running 45 degrees initial timing advance, 15 to 1 compression, 30 lbs. of boost, or a 250 shot of N20 to them........

Just my observations, take them with however many grains (or shovels full) of salt you wish
_________________
2003 Samba Chummie Winner- Best Story

"Those that matter, don't mind,
and those that mind, don't matter"

[Glenn]

[Jake Raby]

The more of one thing that can be sold, the more of that one thing can be boight at a time......... And the CHEAPER it is to purchase through wholesalers or directly from the factory.

SO.......... talking everyone out of 92s and 94s meant thats less to have to stock and would allow MORE 90.5s to be purchased at a time(sometimes drastically in huge quantities), thus dropping their cost on them. BUT the cost for the retail customer stays the same.... (more bucks for the middle man)

Don't be fooled, a certain individual was a marketing expert and a smarter business man than anything else....

I'd like nothing more than to just use one size cylinder and piston for everything- It would be simpler, and simplicity saves time, and time is money..........

Maybe the reason they ran hotter for them is that they were killing the engines efficiency by not giving it proper combustion!

Before somebody jumps my ass for slamming a dead guy- I'm not. They have their ways, which were inspired by his ways(and I have no idea what reasoning he had for those ways). I have my ways which were inspired by trying other ways till I almost gave up on VW engines completely! My way works for me enough to retain my reputation in the aircooled engine industry so it must atleast partially work!

There is no book written on the guidelines that the VW performance engine should include. We are all individuals with our own brain and each engine that is built with the maximum of our capabilities is a reflection of that. Looking inside of something I build is like peering into my brain.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[65bug]

Guys,
Thanks for all the expert input! I really look forward to meating each and every one of you at a "Dyno Day" or some other VW event in the very near future.
I am a engineer by trade and own a online saltwater fish business, so my time is always a issue. I will probably go with the 94's per your guys feedback and I know more cc's is CHEAP HORSEPOWER!
I too know a bit about marketing as well. And yes, by reading all the tech info. I can see that Mr. Berg new his stuff about marketing and was a exceptional businessman as well.
On the 90.5 bulk purchasing issue, that may very well be true as I purchase many things in bulk from manufacturers and save$$$$ I am sure as well that compression ratio plays a large part in their results.
Berg was out of many parts due to their Sweden manufacturer or forging company? I will purchase my straight cuts from CB Performance I guess.

Thanks again!

[EvilBus]

Later tech and machining, the newer p/cs are better quality than when Gene did his writings. Likewise, run Total Seal rings, what blowby? Don't however discount all of his technical experience, RIP.

Did you say hi to Dee while you were there. My wife was out there in Early August, I used just live 5 miles from that place, geeze, Gene Berg, Fat Performance and Rimco just a few miles down the road.. I miss it.
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- JHC de Tejas -

[eddiewubsvdubs]

[
Hey Boss,
I've read alot of your feedback. And I agree with alot of info you've recieved. I worked in Vw aircooled shops for 6 yrs. I can say I've built and tryed alot of combo's. Cooling is very IMPORTANT in a vw motor. Thus the name"air cooled". I'd say 94's all the way if you are going to build a hot rod. But the small fan is kinda on small size for that combo. It will work but it will run on the hot side in summer months. If you run a 911 fan combo. Heat problem eliminated. Can run 10to 1 compression with no det. And run it hard! I have a 2332 now in a 57 oval rag. Your horse power is gunna come from your heads. Well cam and heads combo. So don't be afraid to spend some bucks there. Anyways have fun. That's what its all about color=red][/color]

[Jake Raby]

Oh no.......

That small fan NEVER cavitates, nor does it stop making air! Right up till goes sub sonic and explodes it makes air...

The big 911 fan does nothing but rob HP. Its axial design promotes high volume low pressure air and its shroud has NO WAY of directing the clockwise flow down where it needs to be most.

I have spent over 100 hours of dyno time, and built complete engines (type I and Type IV) just to test this. On the dyno and in the vehicle I have not seen a single 911 cooling system have even head temps as good as a stock system! This was proven on the dyno and then backed up in my beetle as well as a Speedster replica. One test enine was a 153BHP Type IV, one was a 187 BHP Type I and the latest was a 184 BHP Type I.

I have the dyno charts to prove it, some of them are located here at the bottom of the page. Cooling systems without proper positioning of the airflow and without proper pressures are not effective. They can blow 300 MPH and all you'll do is waste power.

http://www.aircooledtechnology.com/type1/dtm/index.htm

Its taken me upwards of 2 years & 15K bucks in parts and fuel to gain this data.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[65bug]

Dudes,
Yes, I spoke to Dee as well. A very nice lady. And Tim helped me there as well. I know much of what Berg speaks is truth. I also know they want to sell their parts to stay in business and make a living.
I purchased their Flywheel nut and blanchard washer because I have heard by many that they are the best. Their oil pump and cover as well.
Jake, I appreciate all the tech input. It sounds like you know your stuff!
Ok, here are a few more questions, What if I did go the 90.5's? Would this be a major power decrease from the 94's? Can you give me a number?
Also, I purchased Jeff Denham new ported and polished heads with 40x35.5 valves. These are cut for 90.5's. just wondering if I should try 90.5's first?
Second questions. How are the CB Supercases? The price is great!

Thank you again

[EvilBus]

[Jake Raby]

The 911 fan was designed for the 911 engine! The 911 engine is 28% larger in surface area than the Type IV and 33% larger than a Type! This greatly effects the pressures inside the shroud as well as the physical limitations of the shroud due to the engine being smaller than a 911!

The 911 engine is about 11" longer than a Type I so the shrouds used in todays market must be made shorter. This limits the shrouds capabilities to use the ORIGINAL DEFLECTOR VANES THAT PORSCHE USED! Porsche shroud was not "EMPTY INSIDE"! They knew they needed to change the direction of the air to boost delivery to the left bank and thats why all their systems incorporated these vanes. The aftermarket systems for VW engines do not use these! Even when added they don't really help much because the pressure differentials are horrible when coupled with the surface area that the TI and even TIV engine has. Pressure is everything inside a cooling system.

Your way of thinking is the conventional way of thinking more air is better. It is not, just because the 911 system can cool a 3.6 liter 911 engine means nothing. That engine was designed to work with the 911 systems flow capabilities and the system was designed by engineers to work with the back pressure that resulted from the spacing and number of coling fins and even their position on the engine. Ialso build 911 engines and their entire composition is vastly different than a VW! The cylinders are short, and the later engines use encapsulated head studs meaning that cooling air never touches them. The cylinder heads are heavily finned with long thin fins instead of short fat fins like VW engines use.

The 911 fan has the capability to produce huge low pressure high volume air from its axial fan- thats true.

Its just too bad that our engines were designed for high pressure, lower volume air and depended more on high pressure to keep the air going where its needed most- around the exhaust ports of the heads!

The biggest misinformation lies in "well if it'll keep a 6 cylinder cool it will damn sure cool a four" Not true, and very far from it.

data don't lie. Making slight changes and comparing data has proven what was first my hypothesis and the end result was an awesome cooling system that uses the stock fan, a superior oil cooler incorporated into the housing internally and proper proportioning of the airflow to gain results.

Keep in mind that aftermarket cylinders, aftermarket heads, and even under cylinder tins vastly effect the cooling of any system! My system, or anyones system depends on the engine its installed on for pressures to be correct- pressures control cooling efficiency. All results may vary due to this.

An engines cooling capability, and a cooling system's capability are two vastly different tghings! The best cooling system in the world does no good on an engine that lacks cooling capability.

The 911 is superior in capability, Aluminum cylinder help it and so does the fact that more money was inversted into its design.

Wanna know anything else? I could write for days on this subject and only tell you 1/4 of what the testing has taught me.
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[EvilBus]

I think you mis-understood, but IMO we're in "violent" agreement here.
I did say that the aftermarket shrouds weren't like the OEM. Since I've owned a few 911s and rebuilt a few of the engines, I understand the differences between VWs and Porsches. However, that doesn't make the 911 system bad. You've done research and that's great, but I've also
seen the Type I/IV 911 conversion kits out there and most of them are just covers with no directional vanes whatsoever. The reality is that VW and Porsche spent lots of money understanding the engineering of the cooling systems for their aircooled designs. When you alter the characteristics of the engine, heads etc or if you require more heat load on the engine that requires more heat dissapation, the stock systems may not be able to handle it.

Unfortunately, to dissapate the heat load associated with an engine, it takes horsepower to handle it and to move the heat away from the engine, whether that's a Type I fan or a 911 fan, air has to be moved.

I know lots of guys who have the 911 systems from a couple of vendors out there, they like the system because of it's "looks" So, it's their money.
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- JHC de Tejas -

[Jake Raby]

Cool!

Yep, and looks kill!

Its just like a hot Blonde. She might look good as hell, but is she able to perform to meet those looks??? Only the data you gain will tell the tale or "Tail" in that instance! The only way to know is to try it out and compre the blonde to a Brunette and a Red head. hats what I have done with cooling systems..

If the 911 system is a Blonde, consider her a dumb, fake blonde- period! She looks good and performs like crap!
_________________
Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell"

[EvilBus]

[Terry Cloyd]