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Posted by: Randal Nov 10 2013, 10:20 AM

We can get the heads configured to support a turbo, cylinders (nickies), great pistons and quality rods are available and there's a ton of aftermarket turbo stuff readily available now.

Looking from the top down, just wondering how much reliable HP you could get out of a type IV?

Or maybe it just better to start with a 2.0 or 2.2 (6)?.

One guy knows for sure, i.e., Britain built a quality type IV turbo motor for his 912.

Posted by: r_towle Nov 10 2013, 09:46 PM

From what my feeble mind remembers, jake built more than a few turbo type 4 motors.

There was also a guy on shop talk forums named Wally who got over 400 horsepower using it as a drag car, race car, and street car all in a beetle.

Posted by: michael7810 Nov 11 2013, 01:01 PM

http://phoenix.craigslist.org/nph/sno/4097501600.html

Here's a twin turbo claiming 360HP for $8K.

Posted by: Randal Nov 11 2013, 02:06 PM

There you go!

Posted by: Woody Nov 11 2013, 03:03 PM

Posted by: McMark Nov 11 2013, 09:41 PM

I wouldn't go so far as to claim reliability on any turbo motor at this point. So far my Turbo 1.7 has been great, but it's only got 2k miles on it or so.

But I expect, that a 2270 with JE pistons, iron cylinders, and 2.0 heads could be built to get between 250-300 - assuming it's built to still make power down low. Probably 50 more if it were 'peaky'.

Posted by: Krieger Nov 15 2013, 12:27 AM

I wonder how/if 1.7 heads could be used for a larger 2270. They do have smaller ports that could help with velocity...

Posted by: HAM Inc Nov 15 2013, 08:19 AM

Big T4's don't want for port velocity. They need flow.
Turbo's increase charge density, and have no impact on velocity.

Posted by: Randal Nov 15 2013, 07:21 PM

Please explain the difference between velocity and flow.

Posted by: SirAndy Nov 15 2013, 07:28 PM

One is speed the other is volume.


Of course in reality it's a wee bit more complicated than that.

Posted by: McMark Nov 15 2013, 08:53 PM

A smaller port trades a lower volume of air for a higher speed of air.
A larger port increased the volume, but at a slower air speed.

A higher volume of air means more potential for power/combustion, especially at high RPM.
A higher air speed means there is better fuel suspension and ignition, especially at low RPM.

You trade one for the other. Another in the long list of compromises that IS engine design. In a simple example, street engines would want increased port velocity because they spend most of their time at low RPM accelerating from a stop. Race engines would want increased port flow because their running at high RPM and want as much air ingested for every revolution (air is power).

As Len mentioned, compressing the air is different than both of these factors. But forced induction is a little like making a small port act like a big port.

Posted by: Randal Nov 16 2013, 10:31 AM

That 2.8 turbo motor would be fun to buy and convert the setup so it'd fit into a 914. Although the 2.8 size would be a weight penalty with SCCA rules in XP.

How much to convert that Mark?

Posted by: McMark Nov 16 2013, 09:01 PM

Sorry to say it, but that looks like the kind of motor you would spend more money 'fixing' than it would cost to build a new one.

-The 1-2 side turbo looks like it'll fit.
-The 3-4 side turbo probably won't fit.
-The distributor is garbage.
-The intakes probably won't clear the engine lid.
-Exhaust pipes from the turbos out the back need to be fabbed.
-Intake system to the turbos needs to be fabbed.
-I wouldn't use the 1.8 exhaust log-pipes on a 2.8.
-Hex bar linkages are crap.
-Blow-thru carb setups can work, but I wouldn't risk an $8000+ investment on it.
-The few FAT performance motors I've heard about were http://www.912bbs.org/vb/showthread.php?43788-Type-IV-FAT-Performance-2650cc-Dyno-spec. So I don't have a lot of faith in whoever is designing their engine combos.
-There are a lot of little things on that engine that I would have to fix because I wouldn't want my name anywhere near them. i.e. The oil filler tube setup.

Posted by: Randal Nov 17 2013, 09:52 AM

Reality is a sometimes uncomfortable.... So I take it it's build it or don't get what you want. Hey, I've been through this exercise before.

Posted by: ConeDodger Nov 22 2013, 08:35 AM

What about your motor Randall? Pull the jugs and pistons, go with low compression forged pistons and Nickies. Have Mark make sparks for a turbo exhaust system. Coil-on-plug crank fired. ITB's and an intercooler then hang on!

Go drive Mark's car then realize, this is a completely stock 1.7 internally that acts like a 2270...

Posted by: Randal Nov 23 2013, 11:17 AM

I really hate to mess with my motor after all the $$ spent. It works and was built by someone who actually knows what he'd doing. Also everything in that motor was carefully procured, checked and or tested before it was assembled. The J&E pistons were rejected 5 times until J&E machined what they were told to do.

Also Len Hoffman says that my heads, while great, are not the best for a turbo setup. Also my cam would need to be changed.

So probably a build starting from scratch.

BTW everyone points to Elgin as the best cam guy around, but would need to figure out which cam would support Hoffman turbo heads best. This unfortunately is a crap shoot that might come out right, but might not and to be honest I don't feel like going on a exploratory journey again. So....

It's pretty easy to look at building a 2.7 or 3.2 liter (6) as there are plenty of folks that have run turbo's porsches and the head/cam combinations are well know. Also the motors are readily available and reasonable. I could run E Mod in SCCA with essential no weight penalty other than the actual weight, if you know what I mean. EMOD would allow up to a 3.2 liter turbo and still the minimum weight would be 1700# with driver. My actual would be more like 1850-1900# with driver.

The big deal would be finding a light weight transmission that was strong and shifted fast. A sequential would be nice, but bring $10-15K. I've heard that Subi gear boxes can be converted to work with a Porsche motor and are strong and shift fast, even if they aren't sequential.

As far as hill climbs I'd probably have to change classes, but with 300RWHP (conservative) I wouldn't mind running with the big modified cars. Could you imagine what 300+RWHP would be like on a hill?

Posted by: brant Nov 23 2013, 06:07 PM

don't forget to add another 150lbs of motor weight when calculating going with a -6

what does your 4 car weigh now wet?
b

Posted by: Randal Nov 23 2013, 06:51 PM

1682#

150# net, really?

I can lose 50# with lighter weight wheels; a bit more changing calipers.

Posted by: brant Nov 23 2013, 09:17 PM

we are really close in weight
I have hit 1826 wet

you are about exactly the same if you add 150

yeah its close to 150
the mag case motors can take 20lbs off of that...
(the reason I rebuilt with one on the 2nd motor)
although f.i. and turbo might add that back

I think I could shed 50lbs if I got rid of my metal front/rear hoods...
another 50 if I cut the metal fenders, and roof off.

Frank Beck's -6 is rummored to be in the 1650 range with his road racer.... of course he out run's GT3's with his 2.5ss, and he is an amazing driver, so you have to have something to shoot for.

Posted by: McMark Nov 23 2013, 09:18 PM

I wouldn't touch your current motor. I would build something like I did with the 1.7. Something just to prove the concept and the combo. See what it feels like and then decide if it's worth building a real motor.

Posted by: Randal Nov 24 2013, 02:16 PM

Good idea.

Posted by: McMark Nov 24 2013, 03:07 PM

I'm willing to work out a deal...

I have a crank, core motors, 2.0 heads ready to go.

Posted by: sixnotfour Nov 24 2013, 07:41 PM

2.0-6 type 4 sale

Posted by: brant Nov 24 2013, 08:47 PM

Huh?
Where

Posted by: Randal Nov 24 2013, 10:34 PM

I'll give you a call next week.

Posted by: Borderline Nov 25 2013, 11:00 AM

Randal, I still have my old 1911 cc engine sitting in the corner of the shop. FWIW

Posted by: Randal Nov 25 2013, 06:13 PM

Thanks Bill. Back at you shortly