I know many people are interested in big bore and huge HP numbers for the T4 engine but I am interested in building a motor with a modest boost in power to 130hp but greatly increased reliability and less of a need to be rebuilt compared to modern engines. As I'm doing more research for my build, I'd like to ask the experts on this forum, what are the main failure and wear points on these engines? I am prepared to spend 10 years at least working on developing this and building an engine that is at least somewhat close to modern standards. Cost is not really an issue either, as long as it doses not stray into high 5 figure land. For example, could low wear internals be developed similar to a turbo application but for n/a and more resistant to wear than what VW put in? For keeping everything nice and cool, I am looking into developing a watercooled head setup but that leaves a problem on where to mount a radiator without hacking into the chassis. Perhaps a steel welded roof is the answer with dual radiators fabricated into the roof. Let me know what you guys think, thanks

If those are your parameters, you might as well call Jake Raby and order up a 2270. You'll easily meet your hp, reliability, & price point, and the r&d has already been done

ambitious.

but I don't think the life span is realistic
even a raby motor may not last that long and you'd be money ahead to buy a raby

also 130hp is significantly more than stock
relatively hard to achieve without a big bore
anything you do to achieve more HP (for example a higher rpm motor, or higher compression) will reduce the life span

with more heat comes less longevity
cooling is everything to these motors.

Why do you think that is unrealistic? Just due to the power output?



Here's a good read over on the samba.
https://www.thesamba.com/vw/forum/archive/i...t-686710--.html

I would think with modern coatings for friction and heat you should be able to get 100k out of a T4. At least the bottom end, might need a valve job somewhat sooner ?

Or put in a low mileage Subaru power plant

More, power, water cooled, increased reliability, reasonable cost. Buy a Suby engine and then you still have 9 years and 364 days left to play.

I think the power output is possible.
just not at the same time as the longevity goal

one way to get longevity might be to build a motor with less HP.. less thermal load
say a 1.6 or 1.7 with only 70 hp.
that motor would be under stressed and might last until 100K

I also think that modern fuel injection will promote a cleaner burn, and less contamination or wear when compared to a carb motor.

a set of nickies
1600 cc
programable fuel injection
and brand new Hoffman heads...

that's going to add up to 10K
but may last 100,000 miles

brant

Ha Ha. Glad you said that, Mark. I was thinking the same thing. And those Suby N/A's sell for $800

Of course, if you don't like my semi serious, semi smart aleck remark, Porsche has already made such an engine. The 2.0 six cylinder engine has 130hp, 100k reliability and reasonable cost. No radiators needed.

Don't think 130hp is unrealistic at all - The main enemy that I see is heat. and rather than increasing displacement by going big bore, increase the stroke.

Not sure where to chime in on this.

First off, a 30% bump in power output isn't modest. That is a lot. If it were easy, VW or Porsche would have done it originally. I assure you, they had more engineering to apply to it than a single man can do alone. Not saying it can't be done, Raby has done great things but now we're into a different debate of power, displacement, and durability.

More power = more heat. More power = more beating on the crank, the rods, the case, etc. Pretty simple from an engineering perspective.

You say that you're willing to do development of water cooling for the heads. At that point why bother? Once you go to water cooling there are already a multitude of other powertrain options.

For me, a vintage 914 is all about air cooling and keeping the car very close to 2000lbs curb weight. My personal analogy is that I have no interest in owning a Lambo Countach with a LS1 powerplant. More power possible? - yup. Cheaper to maintain? - yup. Would I want it - no Fuching way. Not passing judgment on those that might, just sharing my personal opinion.

So now we are down to who are you going to serve with the 130HP T4, water cooled whatchamacallit? That is a very limited market once you sort out the air cooled guys like me, the subie fans, the LS1 fans, the big power 3.xL H6 fans, and the occasional V6 guys.

Don't get me wrong. If you want to do it, you should. It wouldn't be impossible. I just wouldn't expect a return on your time and investment.

I could call Mr. Raby, yes. But this is more of an engineering challenge for me to see what the T4 engine is capable of and what I'm capable of doing myself, a pre-built motor takes all the fun out of it I think, even if it'll be a lot of learning on my part. I've already ordered a stock test 1.7 motor, pulled from a wrecked 914. I'll use that to test different builds and simulate the kind of everyday wear I want it to last. I'm not aiming for Toyota-levels of stoutness right now, just more than stock to begin with. There is no good reason why an engine can't last 100 thousand miles, with some help from engineered parts among other ideas I have. Maybe eventually when I find the winning combo, I can sell engines with my particular cocktail of extreme durability and a slight boost in power over stock.

True but I see it as taking the easy way out haha. It is absolutely easier to swap in a different engine but it isn't the point.

I see what you're saying but for me, this is an engineering challenge. I don't plan on selling my 914, it just has too much sentimental value to me. As far as preservation of history, I'm not using the original numbers matching engine for my challenge, so shouldn't be an issue going back to stock should I want.

I've done research on later VW "Wasserboxers" and they last for quite a while, over 100k in some instances. I think there are several reasons for this, which I've extensively documented and will perhaps detail in a later thread.

Later Wasserboxers don’t make anywhere near 130 Hp and are a nightmare of compromises in both cooling and exhaust. There’s a good reason why so many Vanagons are converting their blown wbx’s for more powerful, reliable subies......me included.

While I get why some people find it necessary to watercool a 914, my own opinion, going back to 1973, is that you destroy the original engineering simplicity and brilliance in the process.

Good luck with your engineering exercise, but watch out for windmills.

Most guys rebuilding their engines will never need to rebuild them again. Very few classic cars get driven any real mileage. Nobody will want to add a radiator to their air/oil cooled Porsche engine. That’s just ridiculous. If you want a well designed, well proven type 4 engine with 130 hp, just dial up Len at the type 4 store. He already spent the 10+ years to develop a kit.

yep, there is a engine kit at the Type4store, Raby's old store. Just build a 2056 with Nickkies, Len's heads with 44x38 valves and heat coated, Raby 9990 cam and lifters and add EFI to it. It will last 100k. The crank is bullet proof and the rods are good but you could go to H beams.
The heads have always been the weak point and Len has that handled and the Nikasil cylinders will go 200k .

I have a 2336 and its a blender . 149 horse min.
And i know the difference between that and a 36horse bug engine
Dont be a clown .... Not me but members who have already commented have gotten several 100k out of their stock 1.7 .... And 42 mpg with a tail wind ...or something

So that is the way to go .

Dont get greedy asking for power and reliability.
Dial one up the other go's down.
Dont apply some modern b.s to
Late 1930s engine technology.
Its futile. To try to get it to last .... you want /6 power.


Cost less to do a 3.0 /6 right ? Or subaru/6

I always tell guys my raby inspired motor can hang with a /6 up angeles crest for 1 run .

/6 guys can run up and down there all day .

That's the practical limit of a big /4 explained .

But mark .h

Knows allllllll

The euro-spec 2.1 made 110, I'm sure with some elbow work it can make 130. I plan on following one of the conversion threads on Samba where some guys retrofitted aircooling with this motor to keep it in line with the spirit of the car. After all, it is, more or less a Type 4. The only problem that I can see is finding an efficient way to cool it to watercooled level temps, this will be great fun to solve.

This is not a mystery bra . look at 911
Nickies.... Huge dry sump oil supply , large front mounted oil cooler ...with fans .... Temps will stay down

I want it all, uncompromising haha. I don't think 130 reliable horses is asking too much from these engines. With reinforced internals and other ideas I have, it believe it can be done. There are so many interesting solutions to this that I can't wait to try. I'll document all my progress on this board of course. I'd love to talk to Raby, if he sees this thread.

Maybe so, but I'm not going to hack up my front trunk for an intercooler. On paper that is a solution but I also don't like the idea of routing oil lines that far, too much potential to fail or have other leaking issues. The temps are only one problem of many which I plan to solve.

You want the /6 .... Routinely go's 300k miles or something crazy like that.

When I used to run Type-4s I had two engines, that way I could always make the next auto-x.

100,000K is a big number on 50 year old castings.

But if your up for the challenge this is what you will need.

New Block, Billet would be my choice.
New Crank solid machined out of billet steel. Oh how seeing chips fly is so much fun. with different Rod bearing diameter. Something from Chevy would work as you can still get good decent bearings from the factory.
Air cooled is fine call up LNEngineering and get some nickes.
Cam shafts are okay it is the lifters that have gone to hell, so figure that one out.
Heads Oy the heads, new castings, get them from HAM or use 911 stuff.
Oil system would have to be dry sump, only safe way to keep oil in the engine and lubing up the bearings.

Last but not least I would look at coatings, balancing, tolerances on and on.

Issue I see with the Type-4 is parts quality in general has gone to hell. We have some good vendors, and some good and great parts, you pay for the great stuff.

But then I would just do a Polo engine if I had the coin.

Write up on what it takes to build a modern Porsche Air-cooled -4.

Is Rothsport now building these? I know I have seen some in Emory's builds as of late.

Edit

Rothsport is building T4 motors.

@McMark has been building some of the Raby and versions of his own for years.

It's not rocket science. It just takes money.

Certainly enjoy a challenge and a good project, but leave things like painting and engine building to the pros who do it for a living and built a solid reputation over time.

Have a built and engine or two? Sure, did they last, not so much.

Rothsport builds the engines for Emory. But those engines are not for sale to the public. They are only installed in Emory builds.

the emory engine which is based on a 964, is completely different than a Polo engine which is based on a 930.

Pete

Why not just buy a modern water cooled engine in a used porsche and be done.

Keep the 914 stock.....the engineers knew what they were doing.

Stroke the smaller displacement and have Len do new head castings and be done if you want air cooled.

9 years is a very long time.......besides the coin you will be spending over 9 years..

The original engine in my car was a 1.7 Djet. It ran for 137000 miles never was opened. Hell I hardly did anything to it. Set the valves every now and then. Quit driving it because the clutch went out. But it was only making about 80 hp

I fully expect my current engine to last 100K mi. (If I last that long)

130hp is no mystery. Water cooled heads? Huh? Depends how hard you beat on it for longevity. For ANY vehicle. 160 out of a T-4 is an entirely different story. At what rpm do you anticipate all this fun will occur? What's the driveline and brake plan? Figure out what flavor of new cv joints you'll be buying. I'd rather put the 40k towards a sorted car.

The first question I have for the OP is how will this car be driven. I'm assuming it's a 914.

If you want 100K miles of full throttle heavily loaded use operating at peak power for very long periods of time like, say, a track car, 100K is not going to happen.

If you want, however, a good streetable 914 with 130hp T4 to last 100K miles of normal street use, piece of cake for a well prepared engine with good parts, provided you have a good state of tune, a good maintenance regime, use the right oil and don't overheat it. Lots and lots of them out there.

You can even keep it wet sump, use the stock crank, rods and case and iron jugs.

New heads with coatings will seal the deal.

Build a nice 2056 and you'll be most of the way there. You can still use iron jugs if $$$ is a problem, go with the nickies if you can. See some of the build threads in my sig. And the 120 whp dyno run in 96 degree heat. Len's heads and good cam selection are key.

I have just added a remote oil cooler/fan as I think the motor could use it. Running around town and autocrossing my oil temps were never over 220 or so. On the highway at 70+ for an extended time they would hit 230/240. So cooler added. I'll post a build thread with pics over the weekend. I expect this one to last as long as I want it to, till I'm ready to build another one or go back to turbo.

But I like motors, I'm a little weird that way.