Big type IVs

[Malevolentfrog]

Here I go again. I have been wondering about something. How much horsepower can a Type IV reliably put out. Before You have case and head problems? In the Harley Davidson aftermarket world You can buy Cases, Cranks, Rods, Barrels and Heads in many differnt combos. From about at last count 7 differnt manufacters. The parts produced are many times better than stock. But they are more expensive. In the VW world You can buy race cases, heads, Cranks, whatever. Is it just because type IV's are not as common. Or that the folks involved with the type IV's are not willing to go that extra step? I see what has been done with the type I and it's very impressive. Go to a VW run or to the sand dunes and You will see a bunch of type I's at 2500cc. And some of the type I's are pulling way more than 200hp. And seem to hold up. I think that people like Raby and others are trying. Things like 911 cooling fans, And the new plated cylinders are a help, Is there any way to strenghen the cases? If not with modern CNC milling machines why couldn't a case be built from Billet? What about heads? It would be expensive I know but why not? The type IV is as good or better in My mind for this than the type I. That's why I like what Raby's been doing, Trying to convert VW Guys to the type IV. If anough interest was built up then maybe. I know whats possiable and what's a reality are two differnt critters. But I look at it like this. The current state of art in the Harley world is 5 3/4 inch stroke and 4.25 bores In Prostock engines that hold up for a season. In the street 4 3/4 inch strokes are common some of them even going 80 or 100,000 miles. What if it was possiable to build a type IV at 3.0L that put out tons of torque and horsepower. That held together. I would think that a 914 would positivly fly with something like that in it. Would it be possiable? I think so if there was enough interest. Let Me know what You think. Thanks

[Bleyseng]

I have been at the 914 game for about 7 years now and everyone wants more power. The rule of thumb to get it is to put in a six motor as there is lots of options there.

I have seen several 4 cylinder 2.5L+ powered 914's that are awesome cars. Daily drivers they are not. Why? Heat seems to be the problem as they run the 103 or bigger pistons. They last upto 30,000 miles before problems set in.

To build a 3.0l engine you run into the cam problem which is the longer stroke rods (past 78mm) hit the cam! Yes, some run a reduced circle base cam ,trick rods, 39gr lightweight lifters to do it. Lots of custom stuff that costs lots of money! When you start to spend over $5000 on a motor to get 200hp it is cheaper and better to put in a six! Heck these little cars were designed for it!
Jake Raby's 2270cc motor seems to be the limit now for a long life high hp (150hp) 4 cylinder motor. That is a 78mm stroke with 96mm pistons. It uses the stock cooling system and oil system. I think with Shad Laws new 102mm pistons this will change though.
I think a 102x78mm motor will change a lot of peoples way of thinking. Being able to build a large motor that lasts 100,000 miles with the stock cooling,oil system, exhaust system is incredible!

The cases are strong! Much better than the type 1 cases as they are made of aluminum not magnesium. I doubt those type 1 200hp motors last 100,000 miles!
Yes, the heads are one of the weak links. Why? They are over 25 years old and made of aluminum. All those heat/cooling cycles slowly destroy them. The answer is to by new! I see they are available in Germany now($$$). I am talking about the 2.0l 914 heads or even the 1.8l heads. Forget using old bus heads as they are surely worn out abd ready to drop a valve seat!
Now if we can only get the 102x78 to run with the Djet.... I would be happy.

Geoff

[J P Stein]

Back when European Car mag was still a decent read, there was a writer there that was building a type 4, along with doing some nice updates to the rest of his 914....a serise of articles.....4-5 years ago.

Anyhew....he gets some race ware through bolts(studs) cause they are the hot ticket. As I recall, he recounted that the suggested torque on these babies was somethin over 60 ft/lbs.
So.....he starts in torquing in steps. Now I don't recall zactly, but somewhere around 50 lbs, his noticed that his crank no longer turned.......OOOPS!

He calls em' and says"what's the deal?".
They told him to back them off till the crank turned.
It happened around 35 ft/lbs. Never saw another article on how it turned out

Geoff:

We can have a couple brewskies and hash this subject out at the NW gittogether (God willin' and the creek don't rise).

[MASSIVE TYPE IV]

200HP is the magic number, the 2270 consistantly makes 130-160HP with near over 120 lb/ft of torque @ 2500 RPM!

[Malevolentfrog]

My Point exactly! If the cam gets in the way of stroke's over 74. Then through the use of a CNC Milling machine and building a case from billet. Why not move the cam a little farther from the crank centerline. Jake said it torque is power. what faster way to more power than increasing the stroke? As for the pail full full of water Story. Why not, just build a stronger crank. Dynamic balancing will take care of the harmonics. It can be done. We have proven it with Harley's. A Harley racing engine may have up to a 5 3/4 inch not mm stroke. And that is with a multi piece crankshaft. I am telling You that it could be done, It's done everyday in other area's. It's just that nobody has tried it with the TIV. Yet! I think that it is just a matter of time before someone does. In order for that to happen. All it will take is more interest in the type IV and one person willing to try. I seem to see this in the Porsche world a lot. "Well that's the way We have always done it" and "That will never work so We won't even try" When You have a attiude like that You are beat before You even start. I think the TIV is a very well designed engine. And like all engines it can be improved. It does have weak areas. So You work on them. And the price of converting to a 6 is way to high. I agree that oil coolers should not cost that much. But even with that a conversion to a 6 is a very viable option. And it allows for a lot more horsepower well still keeping reliability. It's Just that I think that even more can be done with the type IV. Thanks

[Dave at Pelican Parts]

A few points. First, there are people making aftermarket parts. I've seen aftermarket cranks up to 90mm!! There are, I think, aftermarket cases as well. Most are designed more for Type I applications, but they can often be used as (and are often based on the design of) the Type IV. There are aftermarket heads--both Remele and SCAT make them. And we already know about the aftermarket piston and cylinder sets.

The good folks at FAT performance have been building 3-liter Type IV motors for offroad buggies for years. That's why they started offering the 911 fan conversion, to keep a 3-liter Type IV cool.

Why don't we hear of monster motors for 914s? I don't know--you could ask Mike Nugent (2.5L), Tim Hannum (2.6L or 2.7L) and others.

Why aren't they more common? Money. The parts are expensive. The aftermarket pieces are very expensive, and 914 people generally won't pay those kinds of prices. It takes a lot of hand work to put together a large displacement Type IV, as you have to check and re-check and re-check. Plus the quality of just about all of the high-po aftermarket parts is pretty inconsistent and they require significant "tweaking" to install decently. Not to mention tons of other annoyances like custom cooling system and exhaust fabrication.

All in all, it is often cheaper to go with a Six. You get the same or greater displacement, a very thorougly developed aftermarket, that lovely Six sound, and the "Real Porsche" cachet.

Add to that the fact that the stock Type IV motor is actually a pretty good piece. The bottom end in particular is very over-designed, and you can seemingly beat the snot out of it for long periods. (I'm not at all sure I buy the 135 HP upper limit expressed on another thread.) The high-displacement Type Is, on the other hand, are almost all real hand grenades. The magnesium cases, studs holding it together rather than through-bolts, small bearing surfaces, lack of full-flow filtration, and on and on. Those can be rectified with aftermarket parts, but when you've replaced the crankcase with an aftermarket design that uses lots of Type IV featurs (rough dimensions, through-bolts, aluminum material, full-flow filtration, etc.) then you can call it a Type IV just as easily as a Type I.

--DD

[MASSIVE TYPE IV]

Strokes over 78mm are not needed in my opinion, unless you are pulling a trailer loaded with lead up the side of a mountain. Strokes larger than 78 pose all kind of problems, and really only move the powerband down, it's already low enough. Going with a better rod ratio (longer rods) helps move the powerband back up, but then you need cylinder shims .400 thick as a minimum, that makes things pure hell. I have used strokes bigger than 80 on several occasions, but have only went to 84 on one occasion.

The clearance issues are a pain in the neck with the cam, we have ways around it,especially after finding base circles on cams that allow less rod clearancing, and gets things to clear with .050 of clearance without causing lifter bore/valve train wear (too small of a base circle can and will do this)

We seldom use a 2.0 journal on a stroker crank, it impossible to get a good rod ratio with a 5.1" rod and a longer stroke. We use VW Type I or Chevy journals, Chevy jornals are stronger than 2.0, and allow several rod lengths and piston pin arrangements.

We can consistantly take a 2270, and make 130HP, make a cam swap, add some CR and better heads and make that engine 160HP, not many applications need more than 160 reliable HP. The engine is not that modified, as the bore is smaller, and alot of the parts used are VW OEM.

The trick is having an engine that will make power after 5,252 RPM if you want to see bigger HP numbers, before that point torque will always prevail.

There are alot of aftermarket choices out there for making power, and they offer dropped cams and etc, just like was mentioned above, thats the problem, they are aftermarket. I would rather have OEM components anyday, thats why I like the TIV, it was a factory big block.

For the guys wanting the big bores, and have big bore wallets, then we use the Nikisil Cylinders, add some real CR and make power.