90.5 vs 92

Marty · Post by **Marty** » Thu Dec 13, 2001 8:59 am

I know of one that hits 10,000 every once in a while on the burnout.
Lloyd Moshers Manx.
Demello 84 mm wedgemated crank
Carillo rods
Those new long 94mm cylinders with Weisco pistons
SHO heads that have been re-done by Steve Timms with Ti valves and Chevy springs.
51.5 Webbers bt Jack Sachetti (sp).

I will hit the recall every once in a while and it goes right up to 10,000. Please note that I have found tachs that have been wrong by up to 200 rpms but thats still a hell of a lot of rpms.
When he was running the Mag, he would just run it up until it would start to lay over and then shift. All by ear. I thought he was crazy. VW motors twisted that tight sound like a jet plane or a really screwed up vacum cleaner.
I talked him into putting a MSD on it and shortening up the shift points. Guess what - he is going faster now. 11.01 at Palmdale.

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Thu Dec 13, 2001 5:43 pm

90.5s, or 94s are the way to go..

I have not built an engine in over 7 years with 92s...they make big power, but have no lifespan, leakdown has a whole new meaning with 92s...

I use 94s alot for daily drivers, even in 40,000 buck replicars, that are daily drivers.

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Jake Raby
Raby's Aircooled Technology
www.aircooledtechnology.com

Sidewalk · Post by **Sidewalk** » Thu Dec 13, 2001 6:26 pm

If I am going to have to machine, I will just go 94. I currently have 90.5, and will replace with 90.5 because there is nothing wrong with them. If I build another engine, 94's will go in.

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'59 Bug-A few tricks here and there. Stella
'88 Bronco II Sonja

74EMPI · Post by **74EMPI** » Thu Dec 13, 2001 7:32 pm

What is the minimum carbs to run with 94's. John, you mention 94's, then heads, then a stroker crank, but what kind of carbs? Can I run 34 webers (ict's) with stock heads on a 1914? Thanks!

[This message has been edited by 74EMPI (edited 12-13-2001).]

[This message has been edited by 74EMPI (edited 12-13-2001).]

James2 · Post by **James2** » Thu Dec 13, 2001 8:11 pm

Only possible problem I see with the thin base on the 94s or even thinner base on 94s machined for a 90.5 hole(96mm) is if you have a low rod ratio it might side load the piston enough to break the clylinder. Of course this thin base is still supported by the case it self.

JohnConnolly · Post by **JohnConnolly** » Thu Dec 13, 2001 10:13 pm

Sidewalk,

Many guys don't know this, but you can have RIMCO machine your 94s down on the OD bases so they slip into the 90.5 hole! You just need to bore the heads to 94s, and you are set!

John
Aircooled.net Inc

jmillheiser · Post by **jmillheiser** » Thu Dec 13, 2001 10:19 pm

ive herd to do 94s right you need to have the case machined and decked specificly for 94s. then they will run reliably. put a stroker crank on a 94 bore engine and you have a veritable rocket (2165s and 2276s are both potential 12 second street car motors).

even a 1915 will be fairly quick with good heads and carbs.

i wouldn't run 94s on a type3 or a bus though. id run a 90.5 stroker or a type4 swap in either case

Sidewalk · Post by **Sidewalk** » Fri Dec 14, 2001 10:25 am

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by JohnConnolly:
<B>Sidewalk,

Many guys don't know this, but you can have RIMCO machine your 94s down on the OD bases so they slip into the 90.5 hole! You just need to bore the heads to 94s, and you are set!

John
Aircooled.net Inc</B><HR></BLOCKQUOTE>
That is what I have been reading here, but it would require machining none the less. If I am going to machine, I am going to do it the way I feel is proper. I would have to have heads done too.

74EMPI: You can run ICT's. 94 is only 3.5 mm larger.

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'59 Bug-A few tricks here and there. Stella
'88 Bronco II Sonja

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Fri Dec 14, 2001 12:57 pm

When I machine a case for 94s, I take the decks to zero on the case. This is about the only way to get equal deck with the big bore.

I have to say that in a TI I have seen the lifespan of 90.5 and 94s about the same...Just last week I took apart a 2332 with 64,000 miles on it, it was very tired, but ran strong....As long as oil and head temps are kept sane (and this doesn't mean killing all the CR)they will live just as long as any bigger piston. Building an engine with 94s requires a bit nmore configuration work than a smaller bore. I have found 44 x 37 valves to be almost perfect for a street engine with 94s and a sane cam with good CR.

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Jake Raby
Raby's Aircooled Technology
www.aircooledtechnology.com

CalLookVWs · Post by **CalLookVWs** » Sat Feb 21, 2009 9:26 pm

Ok this is a bump on a VERY old post, but I'm running 94's (with Wiseco pistons) in my 78.8 x 94 turbo motor. It also has 10mm studs with case savers. The trick to running 94's with 10mm studs is clearancing the small bumps on the cylinders (in the slots where the head studs lay next to the cylinder, at the case end, and sometimes slightly at the head end). It's a very minor clearance issue that can be taken care of with a small rotory file on a Dremel if need be.