Stocker

Yes I looked through 6 pages of search results and didn't find the answer.

If I put a set of 1.8L pistons in my 2.0L engine, will the resultant increased compression require 89 or higher octane gas to be used?

Before I met the Beta, I'd have said 10.3 would require premium, but these are obviously a different animal.

If you have done it, did you need to increase the rating of your gas?

SOCKS_old

theres not many people who have actually done it, a ton have talked about it though. i know it doesn't raise the compression much, maybe to 11.1:1 or so, not exactly sure..

i would venture to guess that it would be a good idea to run higher octane gas even though the compression isn't super high. i would say midgrade would probably be fine for the bit of higher compression and not neccesarily premium grade (93+) since the difference isnt major.

you might wanna wait for other to chime in though.

Ericy321

I would run higher. It may not be neccesary though. You would have to have someone listen for pinging

Alex01tib

After all that work i wouldnt risk it

AGreen

I've done it, and so far, I'm the only one I know of. I tried running 89, and it felt very sluggish and vibrated more at idle. I'm sure it's because the self-learning ecu was retarding spark to prevent knocking. So in my experience, I run 93. I also have 1 heat range colder spark plugs. If I remember correctly, they're heat range 7.

And they're right. It's alot of work, so don't risk it. You have to take the pistons/rods to a machine shop to have the pistons properly installed on the rods, unless you have an oxyacetyline torch, and they're a b**** to press the pins out.

SOCKS_old

do you have a thread yet reviewing your thoughts on the 1.8L pistons.. i would be interested in a write up on how much different/better it is?

Stocker

Thanks a lot AGreen, that's just the kind of information I was looking for. I do have a torch, but not the $.$$ for premium gas, so I guess I'm likely to have a set of 1.8 pistons and rods for sale here shortly. Unless someone wants a 1.8 shortblock wink1.gif .

I'm with SOCKS on this one... driving impressions? Do YOU think it was worth the effort, and would you do it again?

By the way, it doesn't sound like all that much work, just more steps than your average slap-on-an-intake type mod.

AGreen

First and foremost, you must be joking. How much does $.20 per gallon make when we have an 11 gallon gas tank!!?? Seriously dude? That's $2.20 per fill up extra. I know gas prices suck, but paying $42 compared to $40 is not that big of a deal, and it's not going to break your wallet. If anything, my mileage has improved since doing this mod, so I'm going to go out on a limb and say it almost offsets the cost of 93 octane.

But yeah, the original thread had my final thoughts on it. http://www.rdtiburon.com/index.php?showtop...20&start=20

I'd do it again, given the chance. The whole thing cost me $300, and that included buying all the necessary gaskets, oil, etc. The only thing I'd recommend doing differently is renting a cylinder hone, instead of buying one like I did. $300 beats the hell out of spending $3000 for a basic turbo kit.

One other thing you can do is lower your compression using both the 1.8 pistons and rods, which will bring it down to a safe 7.7:1!! But like I said, you'd spend crazy money on turbo parts, pipe, and fuel management.

Stocker

It's an extra gallon's worth of cost, at the price difference where I live. And when we came out at -$3 on this months budget, every $0.40 counts! wink1.gif (that was a book keeping error, BTW but it's still pretty tight), plus I'm a REAL cheapskate - bag cereal, store-brand bread, etc. Turbo is almost certain to NOT happen on this car, so just swapping the pistons & rods isn't what I'm after either.

I'm only asking because I have a free set of pistons in the engine in the parts car I purchased for a manual transmission swap. It's going to be a while, but I'm also considering doing a mild p&p on the "spare" head, and I'll reconsider putting in the pistons when that comes around.

Thanks for your input!