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914World.com _ 914World Garage _ Jake or anyone else..."smallest" Type IV built??

Posted by: Mueller Mar 14 2006, 09:32 PM

are those really words?? hahahha

just wonding if anyone has gone down in size for who-knows-what reason

Posted by: Jake Raby Mar 14 2006, 09:40 PM

Yes...

For revs when torque isn't needed.

Smallest for me was 64X88 (1550cc) and it was before I had a dyno, built from a destroked 66mm crank, stock rods lightened to hell and back with chevy bolts and an 88mm TI Cima piston.

I have no idea how much power it made, but it would bounce of 8,000 RPM like nothing... It was installed into a single seat sand rail that was literally a death trap for the owner at Glamis in 1994 when he launcehed off a razorback and snapped his neck.

Posted by: Dave Bell Mar 14 2006, 09:59 PM

wild... if my quick math is right... the 1550 at 8000 rpm... assuming it was still breathing good... would be pulling in the same amount of air as a 2270 at 5500 rpm or a stock 2L at 6300 RPM...

How high did the engine spin?

Posted by: Mueller Mar 14 2006, 10:02 PM

QUOTE (Dave Bell @ Mar 14 2006, 08:59 PM)
wild... if my quick math is right... the 1550 at 8000 rpm... assuming it was still breathing good... would be pulling in the same amount of air as a 2270 at 5500 rpm or a stock 2L at 6300 RPM...

How high did the engine spin?

hmmmm....let's see, I've got a spare 1800 motor with a 66 stroke, wonder if those Forged type I Cima 85.5 pistons and cylinders would work?

a 1500cc turbo motor sounds fun....

Posted by: Eric_Shea Mar 14 2006, 10:16 PM

Someone who know's PCA rules may be able to shed some light on "I-Class" (I think? Not sure if that's the one or not...)

It seems to me that a well built 1700 T4 teener should dominate no? I 'think' this is a vintage class with all the 356's etc... That might be a good reason to build a killer 'small block'

I think 70's and 71's might qualify

Posted by: Root_Werks Mar 15 2006, 10:25 AM

Didn't VW use the T4 in the 412/411 series as a 1600cc for a couple of years? I wonder what piston/stroke that had?

Posted by: Brett W Mar 15 2006, 10:34 AM

I think the SuperVees were powered by a 1600cc T4 motor for awhile. Then it was replaced by the Watercooled Rabbit motor.

Posted by: Jake Raby Mar 15 2006, 10:36 AM

The Super Vee had a 1600cc industrial TIV engine as it's base with a 566mm stroke and 88mm bore.

The engine I did had an issue with revs. At the time no lighter weight valves were available for less than a fortune and all we had was VW dual valve springs that would not control the revs past 8,000. It would have spun higher for sure.

Posted by: Dominic Mar 15 2006, 10:41 AM

I remember seing a Formula Super VEE at the track one day with a 1600cc T-4 engine, 1.7L heads, dual solex carbs and no cooling fan...just air ducts to the cylinders and heads (not good for sitting in traffic)

Someone who know these vintage VW race cars may be able to shed some light on that engine?

Posted by: alpha434 Mar 15 2006, 10:41 AM

I've been pondering this one as well....

I've got this 1700 in my living room.....

Posted by: Jake Raby Mar 15 2006, 10:45 AM

I have FSV experience. The engines are very similar to todays F production 914 engines, just a tad less displacement.

170HP is the norm from one, but you can't imagine what it costs to attain reliably.

Posted by: Mueller Mar 15 2006, 10:56 AM

so Jake, I still have that 9610 camshaft I bought for my the motor I sold to Mark Henry.....think it'll work with a small bore motor?

Posted by: Jake Raby Mar 15 2006, 11:00 AM

for what kind of revs? What heads?

Posted by: Mueller Mar 15 2006, 11:09 AM

QUOTE (Jake Raby @ Mar 15 2006, 10:00 AM)
for what kind of revs? What heads?

stock 1.8 heads...they "can" be re-worked if need be

nothing too drastic RPM wise, 7K+ would be "neat"

Posted by: McMark Mar 15 2006, 02:08 PM

If you buy 88 mm pistons/cylinders, how do the heads seal? Do they have that thick of a cylinder wall?

Posted by: Jake Raby Mar 15 2006, 02:37 PM

I had LA sleeve make me some 88mm inserts for a bored out 94mm cylinder. I bored the ID to 98mm and then pr4essed the sleeve in... I worked for uncle sam at the time and had unlimited access to several million bucks worth of tools. :-)

Posted by: Mueller Mar 15 2006, 02:43 PM

QUOTE (McMark @ Mar 15 2006, 01:08 PM)
If you buy 88 mm pistons/cylinders, how do the heads seal? Do they have that thick of a cylinder wall?

i dunno...JB Weld??

Posted by: McMark Mar 15 2006, 06:03 PM

Wouldn't increased wall thickness retain heat? Or is the increase negligible?

Posted by: davep Mar 15 2006, 06:15 PM

I'd think the biggest problem with sleeving would be the heat transfer from the sleeve to the original cylinder wall. If some heat transfer compound was used between them, then most of that problem would go away. The added thickness of the cylinder wall would be a little less of a problem in my opinion.

Heat transfer is one of the blackest of the black arts, and one I deal with daily.

Posted by: Jake Raby Mar 15 2006, 06:45 PM

I had no issues with it..

I used a normalizing process to fit the two together.. I chilled the sleeve with liquid nitrogen and heated the cylinder in the oven to about 500 degrees. I ended up with a few thou of crush and then rebored and honed the cylinder.

Its amazing what you can do when you work in a Turbine engine shop :-)