Who built your engine?

[415pb]

Re-built my own. It was fun, but took me 6 months. Would I do it again? Absolutely.

[lmcchesney]

So what have you decided?
I work with Autocraft engine builder Denny McNuttand am very happy.
L. McC

[Alfred1]

Originally posted by Pritchard
Alfred1-

I unfortunately have no numbers on HP or quickness to give you. I can tell you that the seat of the pants feeling is that I have a bit more power than before. I can't really remember what a "normal" 2.0L felt like to give you a good comparison. All I can tell you is that it pulls strong. I love the feeling of going up a hill and accelerating the entire way up.

The D-jet FI mods were: bumped fuel pressure up to 30psi, enriched the idle setting w/ knob on ECU, dialed in the MPS by ear (I know that some of you just cringed at that thought) at 2500 RPM. The D-jet seems to be able to handle the bigger bore with no trouble. I only increased the displacement by 80 cc so it wasn't really that big a jump.

The extra power I'm feeling is probably due to having fresh heads, new rings and cyls., and the higher compression ratio.


Best of luck to you.

Pritchard

Pritchard,

I'm building an engine identical to yours (are you using the stock cam?) but I thought I'd use only 8:1 c/r. Do you have any problems with pinging or detonation with 8.3:1 c/r? What octane fuel do you use? Thanks.

[Jason Porter]

Detonation shouldn't be a problem with 8.3:1

I'm running 9:1 with nothing but success (91 octane)

[Dave at Pelican Parts]

Depends on a lot of things, though. Ignition advance curves, cam grind, fuel curves, how much air/mixture/exhaust you can move in and out of the engine... It's tough to make a blanket statement about what will and what will not ping.

Though I don't think 8.3:1 would be a problem, even with the stock cam/intake/fuel/ignition. Remember, the European-spec 2.0 ran 8.0:1 and was only spec'ed for mid-grade fuel.

--DD

[Jason Porter]

My set-up is about as severe as you can run on the street with any sort of comfort (this coming from a guy with Konis at full stiff and urethane bushings on his car) and it doesn't ping.

Of course, I got my combo and plans from 2 of the best air-cooled engine builders on the planet (Jake and Otto), but it's still a tightly wound little engine.

If it's pinging with 8.3:1 with 91/92 octane, your timing is most likely the culprit. This assumes we're talking about a streetable cam...

[Pritchard]

I run 87 octane most of the time with no problems at all. I still have the stock cam in it. I wanted to keep the FI and from what I've read here, the Webcam 73 grind requires a little more fine tuning than I am able to do "by ear."

Pritchard

[Jake Raby]

Its that friggin stock cam.... the first thing to do is remove it and break it in half, so someone else don't make the mistake of using it later!

Jason, The cam you have is awesome and will hold 9.7:1 as long as you keep tight deck and keep the heads cool...

[Jason Porter]

Now I just gotta get a Mallory, and drop about 300 lbs...

Time to ditch the roof maybe, hmmm....

[Dave at Pelican Parts]

Note that an aggressive cam will let an engine tolerate a higher static compression ratio... So the stock mild-mild-mild cam is probably about the worst one you can use for avoiding pre-ignition with high compression ratios.

--DD

[Jake Raby]

absolutely!!

[Alfred1]

And for those of us who want to keep the stock d-jet system, the stock cam is the best cam to use to avoid tuning problems. Not everyone wants to put Webers on their car.

[Dave at Pelican Parts]

Yup! There are trade-offs here, as in all engineering and design decisions.

--DD

[Jake Raby]

Another reason to throw that system away... When you have to keep a crappy part, to work best with a system- you are fighting a losing battle.

[Alfred1]

I might as well get rid of my whole 30-year-old car then and buy an RSX or something. Nah, I'll just build my motor how I like and you can build yours how you like.

[Jake Raby]

Yes, Alfred- You should.

[lmcchesney]

If you can not get the D-jet to provide what you want, why not convert to a MegaSquirt or the future Kit Carson system? It is my understanding that the overlap of the cam is the limiting factor with D-jet and aggressive cams.
L.McC