Big Fours

[sjhenry1075]

Hey everyone..

On the main webpage under tech articles there is an article titled "Big Fours" which explains the build for a 2.5 liter four cylinder engine for the 914. I have a few questions regarding this process and tried contacting the author of the article but the email address is no longer valid. Is anyone aware of a current email address of the author or has knowledge of this engine?

Thanks!

[John Rogers]

Well I haven't heard anything from Mike for years and he may have gone the way of those of us that are too old to do this stuff any longer? I had both a 2.4L four and a larger 2.8L four in my dedicated race car and finally gave up and went to a six as in the long run it was cheaper. The 2.2L six lasted 26 race weekends as opposed to either of the fours where we could get 4 weekends at the most! This was a road race vintage race car, no street use and very little autocross running even.

So the lessons we learned are
1: have a very competent shop do the machine work and assembly. These are getting harder to find.
2: Run a dry sump system as the engine will love for it.
3: Use a huge front mounted oil cooler for the same reason.
4: Build a "torque" engine, not a high revving engine as it is longer life.
5: Get the best heads and valves possible.
6: Use a transmission cooler and after market shift linkage so you do not miss any shifts.
7: Use a 911 style alternator/fan/cooling shroud and all engine sheet metal to help cool it.
8: Use spark plug temp sensor and an O2 sensor and an aftermarket tach such as one of the Autometer memory tachs.

In the end it would be cheaper to put in a 2.4L or other type of six in but that is dependent on what you want to do. Good luck with it.

[sjhenry1075]

Mr. Rogers thank you for your reply. I won't be doing any racing, I just want a little more power than the current 1.7 has to offer. I'd really like to build my own engine from scratch without the cost being too outrageous. Id also like to make as little modification to the drive-train as possible to keep costs down.

[Tobra]

Look in to a 2270, I believe Mr Raby has a kit to build one

[John Rogers]

Well in the case where you want just a little extra power, I'd suggest a 2L or 2.2L with a slightly higher compression, maybe 0.5 or so, slightly hotter cam so you cam stay with the stock heads and valve train. If you get radical with the heads then reliability goes down as type 4 heads really suck when it comes to hop up work. This sort of thing you can do if you have the necessary support machine shop available.

[Dave at Pelican Parts]

Originally Posted by sjhenry1075

I just want a little more power than the current 1.7 has to offer.

In that case, going with 96mm P&Cs (get the version intended for 1.8 motors and machine the heads to fit the cylinders) will give you 1911cc. If you keep the relatively-high compression of the 1.7 motors (except the 73 CA-spec one) you'll have a nice bump in power.

If you change over to carbs or an aftermarket EFI, you can change the cam out for something more aggressive, and that will get you more top end, usually at the expense of lower-RPM torque.

Head work can unlock quite a bit of power in these motors, assuming the cam works well with the heads, and assuming the exhaust can keep up.

If you can lose all heat, a tuned header will improve even a stock motor. You can get a header with a heat exchanger section, which will provide about enough heat to defog the windshield. Sit down before reading prices on that system, though--it's a work of art, and costs like one.

If you find a set of 2.0 crank and rods (the Bus parts work fine), you can use the 96mm P&C kit for 2.0 motors and get 2056cc. Which should again be a nice bump in power.

The 103mm and 105mm P&C kits are often problematic. I know people who have had to go through several sets to find four that are useable. And often they require machining anyway. And they do tend to distort after they get heat-cycled a bunch of times, making them less useful.

If you want to go the "cubic dollars" route, you can get machined aluminum P&C kits in larger sizes; google up "nickies cylinders" for some idea of the costs. Note that the stock heads really won't support large displacement motors, so you will definitely need head work by someone who knows VW Type IV engines.

--DD

[flmont]

Dave,..What kind of power and Torque,..R we talking about,...I like more Torque than top end speed,..But can U get to 130-140 HP,..with strong Torque ???? I now have a 76' 2.0 to build with I guess Carbs,...altho I perfer F. I. building for southern AZ ,..roads and mountain drives Thanks Frank

[sjhenry1075]

thanks for all the responses, they were definitely helpful! Can anyone recommend a good machine shop in MD? I'd really like to "build" the engine myself, but machine work is obviously something that has to be done somewhere else.

Thanks again!

[Dave at Pelican Parts]

We have seen dyno plots of over 200 HP from a ~2.3L Type IV motor, and I think the torque was near that value as well. Be prepared to spend well into five figures for one of those done for you, though.

If you want torque and aren't worried about power, you don't have to throw as much $$ at the heads or the moving bits. Lower revs mean lower stresses, as well as not needing super-high-flow ports to support them. If you want torque and don't care much about longevity, the large-displacement low-tech motor (cast iron cylinders, minimal or moderate head work, etc.) can be a good option.

Depending on exactly what you do to the engine, power and torque levels can be just about anywhere...

--DD

[lorenzoscribe]

I went with the 1911 option. 96MM bore with the 66 MM stroke, 40MM IDF Webers. 9.3:1 compression ratio and a cam. I also put on short velocity stacks that helped the power roll on smoother. I am currently using standard stainless heat exchangers and a Bursch muffler.

The engine gives good power, revs quickly, yet has good torque. Use 50 series tires to help the gear ratios. I found that made a big difference. It is loud but I don't find that to be a problem.

The only downside of doing it this way is that the big engine puts the 914 into the SCCA D/Mod class for autocross were it isn't competitive when run with street legal equipment.

Larry Steckel
1971 Porsche 914

[sjhenry1075]

Thank you all for the input. I like the idea of a tuned header, I have no plans of driving the car in the winter so no heat isn't a problem. As much as I'd love to invest five figures into the engine, my wife may feel differently. I have no plans to race the car, I'm just looking for a little more get up.

[Joe Ricard]

I finally pulled the plug on my 914 hopping up stuff after about 10 years of dodging cones in a parking lot driving to and from events. 1.7L then 2.0L then 2098cc finally 2316 Raby kit. That had to be the most fun of all and it was quite streetable untill I built a 914 race car from a hunk of trash. and just ran the pee out of it on track.

Now I have a 95 M3 and am hopping it up (of course). This is one heck of a car compared to a 914.

[lorenzoscribe]

Please don't spend five figures on a Type 1V engine. We aren't talking about a 930 turbo motor.

I had my 1910 engine built at a very reputable VW shop over a winter for $1700.00. Total. He does scads of air cooled VW engines. A type IV is nothing exotic.

I had the engine all ripped down when I delivered it. The shop ordered the set of pistons, bearings etc, and when I got it back, I had to re-install all the tin, the accessories and put it back in the car. No big whoop there.

If you go to a shop that says "Porsche" on the marquee you are going to pay too much to a mechanic named Wolfgang. There's a guy out there named Jim that can do the same job at a much better price.

After all, a Type iV is really just a VW bus engine on steroids.

Use the extra money for suspension, interior and tires.

Larry Steckel
1971 Porsche 914

[flmont]

Yes,..Larry Iam with you,..looking to get 130 or so HP,..but strong Torque,...the only Bug shop here in Tucson,az dosnt work on Type 4's belive it or not,...So I need to find someone close to home to help me out,....Thanks Dave for the Info.....Frank

[Dave at Pelican Parts]

Originally Posted by lorenzoscribe

Please don't spend five figures on a Type 1V engine.

If you want over 200 HP, light weight, four-cylinder power that will last 75K or 100K miles, you either have to know an awful lot, or you have to pay someone who does. (And the builder in question is named Jake, BTW, not Wolfgang.)

Fast, reliable, cheap. Pick at most two.

130 HP is a much more reasonable target. You can probably get there with a fairly hot 1911cc motor, but the 2056cc would be less stressed to do it. A cam, carbs (or aftermarket EFI), compression, and headers should get you in the neighborhood. You'd probably want to change over to 1.8 heads, or at least open up the 1.7 registers to fit the 96mm cylinders and upsize the valves to the 1.8 sizes.

--DD

[flmont]

Hahah,..Yea, always a trade off, I know,..I do have a 74' 1.8 liter,.. so U say use those parts on a 2.0 case ???...I need a book...dont I ,..LOL Thanks agin

[flmont]

But ,
I did read Mr.Nugents,...big 4 article,..just tonight,...and he seemed happy with his set-up for around 3 K,..????

[sjhenry1075]

I'm not looking for a lot of horsepower, maybe something in the neighborhood of 125-140. I read an article on 914world on how you can use the 1.7 case when building the 1910, it even went on to state that there are advantages of the 1.7 case over the 2.0. I understand the majority the money will be put into the internal parts and the heads. Would it be better to use 1.8 heads or have the 1.7 heads machined? I think I read somewhere the 1.7 heads are somewhat weak.

[Dave at Pelican Parts]

There's nothing special about the 2.0 case itself; you can swap the crank and rods from a 2.0 into any other Type IV case without any problems.

I don't really know if 1.8 or 1.7 heads would be better to use. I'd be inclined to start with 1.8 ones, because the registers are larger so that's a bit less work. If you're going to the 1.8 size valves, then starting with the 1.8 makes that easier. If you're going larger, or doing extensive porting, then either would probably work as a starting point.

--DD

[flmont]

Cool,...Thanks Whats the best Machine shop to do Type 4 work around southern AZ or CA