skool me on 914 engine hopup

guy at work just bought a 73 914 2.0 as a project. He ask me what I thought he needed for 150-160 hp. He's overwhelmed with all the webpages and vendors for 914 stuff (and the $3000-10,000 price for crate engines). He's decided to tear down the original engine and rebuild it himself so he has asked me all kinds of questions about niki jugs, CNC heads, whether he needs aftermarket rods, what cams, whether he should go with carbs, etc. His budget is about $3k with him doing the engine assembly and installation.

I first told him a Sube transplant would be the best situation but he wants to keep it close to original.

I know nothing about 914 engines but I gave him some basics. I said other than a rebuild he needs to upgrade his original electronic fuel injection to aftermarket programmable such as MS, get a decent street cam with small duration and high lift, I noticed webcam had a 265 duration that looked promising, and up the CR as far as he dares with an aircooled street engine (prob about 8.5:1?). I guessed he could get to 140-145 hp with this recipe. (??)

was I close? Any other pointers for him? headers? porting? Are waterboxer heads worthwhile to be able to up the CR higher (but require larger valves and porting)?

Rotary swap

V8 swap

I'm certainly no engine-builder, but I had a 2.0 liter 914 engine built for my race car (of long ago). Engine was mostly stock, balanced, with 8.0 compression pistons, very open exhaust, Weber 44mm carbs, and a 356C distributor. It was built by a guy who used to build Pro-V engines back in the day, and he really stuck it to me. When I got it back it barely ran and my wallet barely existed. But after several years of pain and suffering, and finally finding a good race shop (Cox Motorsports in Kansas City), it ran fairly well. It never saw a dyno, but based on on-track comparison to another mostly stock 914-6, I would guess that mine had similar power. The 914-6 was rated at 110 horsepower, but given that we were all running open exhaust, call it another 10 horse, so maybe 120 at the crank. But that was not a muffler you'd run on the street. I'm sorry I can't give solid numbers but I don't have any. But at least it gives you a start. My engine was severely limited by the stock cam.

My foggy memory says that pro-V engines were based on the 1.7 liter block and made 160-170 HP, so about 100 horse per liter for a full-on race engine with short lifespan. Your friend wants to make 75-80 horse per liter on a street engine (with driveability and durability) and I think that might be a stretch. However, it is possible to up the displacement but don't call me for any estimates of durability.

Personally I would: balance 8.5 compression megasquirt for fuel injection and ignition cam Shift at 5600 RPM Have fun! Even 140 HP in a 2000 pound car will be fun.

I was told the number one way to blow up these motors was neglect the oil. Duh. But the number 2 way to blow them up was to overrev them. Factory rev limit was 5600 and (I was told) they blow up at 6000. This is not a 911 engine, don't try to rev it like one.

Good luck!

David

no idea what it would take with the early 2.0. but just to put it out there, ive seen a few 914's with mid/late 70's 911 2.0 liter flat sixes (200 hp ?) that hauled arse, though the subie conversion might be a better/cheaper way to go than all of the above. 'excellence' did a very good article on one last year some time.

That would be an early 911 engine (2l) and pretty much a 914-6 replica though.

Mind you, there should be enough space to stick a 3.2 in there if a 2l fits .

I know a few of them with 3.8 liter flat sixes.

160 is damn near impossible with a type 4. Jake Raby is building a "hot" type 4 for our shop right now that we are hoping will dyno at around 140. and that literally has the BOOK thrown at it. (Shameless plug, but if he knows what he wants, have him give me a call, and we can talk about it.)

160? better get a 6 cyl from a 911 in there.

Buy the back issues of GRM's 914 build.

Wasn't that easy?

Dan

RandyS wrote: He ask me what I thought he needed for 150-160 hp.

RandyS wrote: but he wants to keep it close to original.

Unfortunatly, these two statements are at odds with each other. And while Porscheofiles (?) would scream nasty things, the best bet would probably be the Sube transplant you suggested... But that is just my opinion... lol

Yeah, 160 is not easily attained. The cases tend to start doing weird things with big power over about 6500 RPM. There are billet cases available but now we get into the realm of ridiculously expensive.

When I had my 1971 1.7 car I dug into the possible upgrades, and for a streetable motor that will live: start with a 1.8 914 or a 2.0 bus motor. (The 1.7's stud spacing precludes going much bigger than stock bore and 2.0 914 heads flow well but are prone to cracking.) There are several 2.5 liter bolt on big bore kits, this will make the motor 'undersquare' so it will rev better. Long stroke 'oversquare' engines tend to move the power lower in the RPM range. Balance the reciprocating assembly, this is very important on boxer layouts!

Have the heads ported by someone who knows what they are doing and go with big valves, all easily available from lots of advertisers in Hot VWs magazine. Type IV's have a nasty habit of dropping valve guides, there are 'snap ring' type guides which are excellent insurance against that. There are also large diameter pushrods which are way stiffer and lighter than stock ACVW and they can be custom made to keep the valve train geometry correct, which is pretty important.

Choose a cam which suits the rev range you want. Web-Cam and Reed both have numerous grinds to do pretty much anything you want and are surprisingly affordable.

Dellorto or Weber carbs make good power but air cooled engines are very finicky about jetting, particularly in hot dry climates. The stock 914 FI system is sorta caveman but is adequate for a street motor, Megasquirt is probably a better bet. Either way you go, pitch the dizzy in favor of crank trigger ignition.

As mentioned earlier, a free flow exhaust is a must.

For cooling, make sure the stock engine tin is all present and accounted for and just as important that it's sealed properly at all the joints. The 914 has a bellows type thermostat which opens and closes flaps to keep the engine in the desired temperature range and those have been known to fail. The debate about whether they are really necessary has gone on for years. I removed all that from my car and blocked the holes. The stock oil cooler is barely adequate for the stock motor, it's best to get one of the blockoff plates which allow you to run a big oil cooler. The best place to mount the cooler is just ahead of the cooling fan air intake. An oil thermostat is definitely a good idea. Early 914's also had a nasty habit of overheating at highway speeds; the design of the car means there is no 'ram air' effect to push air into the cooling system, the fan has to do all the work. Porsche fixed this by adding two small flaps at the front of the engine compartment just ahead of the cylinders, this created a low pressure area which helped the stock fan suck air in from the top. If those are missing, make a set from aluminum. A bud with a 2.0 914 added a small pair of NACA ducts to the sides of his car, this brought the engine temps down considerably at highway speeds.

All this will probably get you to around 135 HP (not a real big jump) but the engine will live. Avoid abnormal aspiration, detonation is a real problem!

SBC!!

If the heads on the engine are the original 2.0 914 heads then they are the best of the type 4 heads. They should have 3 intake studs instead of the 4 found on any other type 4 heads. The 2.0 914 heads have larger valves and a different spark plug location then other type 4 heads.

I would tell him to do some reading at Jake Raby's forum.

ratghia wrote: If the heads on the engine are the original 2.0 914 heads then they are the best of the type 4 heads. They should have 3 intake studs instead of the 4 found on any other type 4 heads. The 2.0 914 heads have larger valves and a different spark plug location then other type 4 heads. I would tell him to do some reading at Jake Raby's forum.

Should also be mentioned that if they are the original 2.0 heads they have probably dropped or started to drop a valve seat by now and will be cracking between the valves as well. Good clean 2.0 heads are like hens teeth. They make good power but they have weaknesses.

I'd go for the subie and never look back.

One of the most effective swaps is a 3.6L from either a 964 (250hp) or 993 (270-280 hp).

These are not cheap, but straightforward and will take 914 from a little car into giant killer. Howver those swaps will need alot of chassis & running gear updates to deal with the power.

A nice swap I have seen a 3.0L motor from a 911 SC. 180 hp and good for 300k miles in stock form. Plus if you do 5 lug converson you can still run the car with narrow fenders and 15" wheels. Makes it sort of a "sleeper" 914.

Or you can just enjoy the 2.0L as is. Not powerful, but raw and nicely balanced.

I would not bother with a subaru swap. Get a 911 motor and it is easier because it sort of fits and there is no cooling system to deal with.

Needs 100% more LSX.

If you want to keep it in the family, pick your favorite air cooled six.

Sell the 914, add the 3 grand and buy an MR2 turbo

Sorry, over ten years ago I had a 914 2.0. Spent about 2500 on parts and machine shop work. Put it together and had maybe 120 HP. The next bad news is the brakes won't handle the power and the chassis will twist under that sort of stress.

Just for giggles tell your buddy to put a jack under the door and lift the car. Drop it real fast and watch the door gap change. Then think about doubling the power on that chassis.

Get nice heads from Jake Raby. Build a 2056cc big bore. Keep stock fuel injection. 120 HP is more than enough. Cooling will be a breeze.

Anything else is big buck adventure and will result in months of work with constant re-do activity.. Beliviee me I have 35 years living with these cars. Simple is always better.

And I can assure you stock brakes are more than adequate if setup properly.

Dont underestimate what it takes to do proper six cylinder conversion. Its a big job!