Here is my question of the day for you engine Gurus, Maybe two......

Can I bump pistons and cylinders to 96MM Run 2,0 heads, and stock fuel injection without splitting the case and doing a cam etc?

Would I be better off throwing carbs on it? I have a set of 44IDF's but I think it would be overcarbed.

Thanks
John

Nevermind: I just noticed you said 1.7L in the title, but talked about 2.0L in the body of the post.
Disregard.


Stu

I am no Guru, but I am voting YES. I can't think of any reason you can't do that. You will need 2.0 cooling tins. The spark plugs are located in a different location vs. 1.7. I kept my 1.8 heads, but Len at Hoffman Auto repaired the cracks and upgraded them with wider ports, valves, rockers and adjusters. So my plugs and intake bolts stayed as a 1.8.

CR and CI calculator

Size wise you get a 1911 cc engine that breathes like a 2056. Try the link above.

You will need to run the 2.0 injection setup as the 1.7 runners wont bolt to the 2.0 heads. Will probably take a bit of tweaking to dial in but you should be able to make it work.

John,

While not answering your question directly, this link should at least give you some idea's.

Bumping a 1.7 to a 2.0!

Doug

Good seeing you yesterday John, your car is coming out really nice!
Why not stay with the heads, tin, D-jet for the 1.7 and just put 96mm kit?
I'm not sure if the heads have to opened up for the 2.0 jugs or not?

EDIT: From Jake's article:

5-Now more on cylinder heads:
If you are staying "Bone stock" with camshaft, lifters and etc feel free to simply have your stock 1.7L heads bored to a 105mm register size to accommodate the larger 94mm (or 96mm performance) cylinders. You should always have this work completed by a reputable Type 4 cylinder head specialist! Trusting this and any other Type 4 head related work to a local shop not seriously experienced with these cylinder heads can easily and quickly turn your engine into a failure statistic. We trust all our head work to Len Hoffman at www.haminc.biz and you should as well-


I can help with the D-jet testing and setup...

Would be easier for you to just have your 1.7 heads cut to accept 2.0 jugs.
You will need headwork done anyway, so why not use heads that will accept all induction gear you already have.

You will be building a 1911 cc engine, and they can be great little plants. You can't change the cam without splitting the case, and there are stock FI cams that work better, but what you have in your bottom end WILL work.

Zach

So if I want to use the stock FI, I am better having the heads machined to accept the new cylinders.

But if I decide to choke down the carbs so to speak, I would be better off with the 2.0 heads?

Thanks Scott,

As you can see, I was listening to ya!

yes, as athe 2.0L heads give more hp with their bigger valves, ports and plug angle. If you use the 1.7 heads have them rebuilt with 42x36 valves along with the 96mm cylinders its gives you a nice engine. Set the CR to 8to1.

Not to speak for John, but his goal at this time is to stop some of the bleeding and get the car on the road.

He has a 1.7 he got from dANNy that is supposed to be low miles. I'll let him tell you why he has the heads off, but doesn't want to split the case.

I suggested that I would put the 96mm kit on it "just because" he is right there and if the engine turns out to not be good, he can use them on whatever engine he decides to use. Since he already has all the parts I also suggested he stay with the d-Jet.

So the idea here is not to build a long term engine or engage in more project creep, but to get the engine running well, the car on the road and decide where to go from there.

With that in mind, big valve heads and the like are out. Once you go that deep I think he should just keep looking for a good running 2.0 that is being replaced with a 6, but that doesn't get him on the road this spring!

If the goal is to get on the road just slap the 1.7 back together and drive
Don't underestimate the smiles per gallon from a 1.7 TIV

However,

I already have a nice pair of 2.0 heads. So a P/C kit with those and my carbs might be a strong option. I can use my 1.7 tin and make new spark plug holes and find some rubber plugs for the old.

OR,
find some 2,0 upper tin.

John

Heads should be at least checked before putting them back on the engine. A dropped valve seat will destroy those new pistons and cylinders. IMO it's penny smart and pound foolish to skip the headwork.

As an object lesson. A member who lives near me dropped a 1.8 in his car to stop the bleeding and get the car on the road. Few months later the engine was out with a bad head. A core head was slapped in just to get it back on the road. Lasted a few more months before dropping a seat. At that point the engine had to be rebuilt. The guy knew he was driving a time bomb and went with it anyway. It blew twice. And both times included limping the car 60 miles home on three cylinders and makin horrible sounds on the fourth.

My advice is not to just stop the bleeding. Do the heads right. The rest will follow suit.

For what it's worth I have no issue taking heads to my regular machinist. Some may differ with me, but many machinists know how to deal with aluminum heads these days.

Zach

The 914 variant of the 1.7 runs 90mm high compression domed pistons so enlarging to 2.0 jugs means you will probably be running 93-96 mm flat topped pistons with a 1.7 head. That's a compression loss and possibly a power loss.

Until you fly cut the heads to make up for the loss in compression. Not a big deal since you are cutting the heads anyway for bigger cylinders.

Zach

Thanks Zach,

The 2.0 heads I have are nice. But they have sodium valves that I am replaceing.