1porschenut

I have a 75 with a 2.0 motor Im thinking about putting either 103mm or 104mm pistons in it which on is better and what is the diferent last question what all do I need to do to get it to work.

Thanks

racer

Carbs
Cams
Head work
Exhaust
cylinders

at least all those "big" things come to mind.

I would ask how do you plan on using the car? Most big bore motors like this don't last too long overall. How much HP are you looking for?

If you haven't check out jake raby's shop about high hp VW/914 motors. While his motors, and kits, are very expensive, they are well known to be very reliable and well engineered.

1porschenut

My plans for the car is to be turned into an autocross car. As for hp i really dont care how much.

Matt Romanowski

Yeah, list includes

heads
valves
valve springs
lifters
pushrods
lifters
cam
pistons
cyclinders
rods
crank
cam
case mods
oil cooler
intake maching
carbs

Othat than that, it's real easy.

Matt Romanowski

and don't forget wrist pins and rod bearing sizes, with appropriate rod clearancing and rod bolts. Case bolts too while your at it. And head studs. Everything else is stock.

Matt Romanowski

Oh, and ignition. You'll probably want to go through the distributor or do an MSD one.

Matt Romanowski

I forgot the exhuast and exhuast studs while your at it.

Oh yeah, a clutch and pressure plate too. It sucks when you take it out for the first ride and it slips right away.

racer

Muffler too.. no point leaving that stock..

but c'mon matt.. he doesn't care about HP


Most autocross classes are fairly regimented. Not caring about HP with a nonstock motor is like being a "little pregnant".. either you are or you aren't.

Keeping it stock, but a thorough rebuild will ensure you are getting all, what, 86-90hp out of it? Next might be euro pistons (higher compression, maybe 100-105hp) Next, more practical mod, is a 2056 motor.. can be spec'd for about 110hp (stock fi) up to about reliable 130hp.

I ran a 2056 in my '70 914 (mmm 1980lbs ready to "fight") and 120ish hp. Made it remarkably more fun to drive and keep up with bigger, unsuspecting cars.

imho, once you get over 120-130hp, you really need to focus on suspension and brakes. So 140-150hp would want bigger brakes... and better suspension..

See how these things keep snowballing? soon your in for $10-15K !

Jay Gratton

Anything else Matt? I bet he is thinking staying stock looks really good right about now.

Matt Romanowski

$10-15k is funny. Bigger motor, suspension, 5 lug, big brakes. While you're doing all that, you might as well restore the car since you're putting so much money into it. I passed that figure long ago.

Autocross rules are a little wacked, so it takes ton of planning. My car looks completely stock yet gets put in the most modified class because of the suspension and motor. As soon as you change bore and stroke you are screwed.

Oh, and don't forgot either lots of time (and double the budget) or lots of money for books. Nothing goes together in a big motor without lots of work.

Matt Romanowski

You can do a nice pretty stock rebuild on a 2 liter with some cam and a little head work and get 120 hp.

As for brakes, a good stock system with Raybestos pads will work up to 140 hp or so. Once you start going over about 130 mph on the straights you kill pads real quick.

racer

That's true... Lets not forget about the flares.. and subsequent rust repair, body work, stiffening kit, rollcage.. new seats, harnesses, FE system.

Jay Gratton

There comes a point where you should just drop in a 911 a motor and call it the day.