can i use bigger jugs on my 1.7 engine

[Mad-Mac]

I want to rebuild my 1.7 motor and need to know if i can put bigger cylinder jugs on it like a VW motor to get close to a 2.0 motor.I also need to know where i can find a low price kit.Thanks for all the help guys.

[ruddyboys]

you can put the big bore 96mm pistons and cylinders on the 1.7. You can get the kit here at PP.

[Zeke]

You will have to bore out the case (spigots). Have your case decked while you're at it. You need a 71mm crank w/ 94-96mm cyls to get to 2 L the easy way. Otherwise, you need some bigger cyls than stock. That's more money. some people like a big bore/short stroke motor, though.

[tshih]

I have a set of original 2.0 Cylinders and pistons for you to bore out for bigger displacement if you're interested (I'm selling them for $100 plus shipping). They are left overs from a rebuilt 2.0 engine in progress.

My email is Tshih@jstar-research.com if you're interested.

Tom

[Scooter311]

Hi all
I have a 1.7 also, and was wondering the same things. I think I recall a topic not too long ago that mentioned needing to use the 2.0 conn rods also. Is this true? What else needs to be done to accomodate the changeover? I might be able to pick up a set of 1.8 heads and 2.0 P/C's real cheap in the hopes of a big bore short stroker like Zeke mentioned. Would this combo work? What about carbs - 40IDF's?
I was hoping to just put in the rods, p/c's, heads, hotter cam and carbs- is this reasonable for those of us with these motors?
Mad Mac, I'd be interested in your progress if you go through with it.
Cheers,
Jeff

[Griznant]

You won't have to bore out the case for bigger cylinders, but you will have to open up the head register to fit. The slip-in big bore kits for the 1.7L heads are not a good idea as they are very thin. Just have the head work done and open them up accordingly to use the thicker wall cylinders. You don't have to do this with a 1.8 or 2.0L as they already have the big register.

You can get a set of 96mm big bore pistons for the 66mm crank to get you a 1910cc displacement. This should wind out nice with the short stroke. However, you can also step up to the 71mm crank and rods if you want to and put that in your case to get a 2056 with the 96mm bore.

Just remember that there are three sets of 96mm pistons/cylinders. Slip-ins for the 1.7L, slip ins for 1.8L, and slip ins for a 2.0L. With a 66mm stroke you want the ones for a 1.8L and have your heads machined.

I put a 71mm stroke with 96mm pistons in my 1.7L case and had my 1.7L heads reworked for the bigger bore, bigger valves (44x36) and full port and polish. This will get me a 2056 with decent midrange to high-end power with my cam choice.

Later,

G

[Scooter311]

Ahh, thanks. Looks like I may shoot for the 1.8 heads and 2.0 cyls. But what about the rods? I'm gonna get the entire deal balanced also, that'l help smooth things out.
May I ask who did your heads? And how much? I just did my taxes, and plan on spending it before I get it..............
THank again,
Jeff

[hardflex]

for a 2.0, you basically need 3 things as a unit, 71mm crank, 2.0 rods (they're different length than the 1.7, 1.8s) and 2.0 piston (a different pin height.

Griznant- what compression ratio are you going to run with your setup? I had figured flat top pistons to be about 8.8 to 1 with 1.7 heads.

[Griznant]

Originally posted by hardflex

Griznant- what compression ratio are you going to run with your setup? I had figured flat top pistons to be about 8.8 to 1 with 1.7 heads.

I'm shooting for 9:1, but anything in the 8.8-9.2:1 range will work.

I should be getting my heads back this week. I'm pretty excited (especially considering they cost almost as much as the car!) to have these done. I've gotten some good advice on how to set this engine up, and I'm looking for around 120hp as a conservative estimate with good midrange power.

Later,

G

[hardflex]

If you can post some pictures of your heads when you get them back, it would be enlightening, particularly how they treat the exhaust port looking into the exit port.

Are going to run Carbs or Djet, and which cam did you go with?

[Griznant]

I will post pictures of it when I get them, no problem.

I'm running a set of 44mm Webers, EFI won't work on this one.

As for my cam, well, it's an ancient Chinese Secret, and selected for this setup. It was recommended to me in confidence, and I don't want to overstep my bounds on this. I can tell you that it is a Webcam though, and that I would only use their products.

I'll post some pics when I get the heads.

Later,

G