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

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

Re: About my engine...
 

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.

Detonation shouldn't be a problem with 8.3:1

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

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

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...

no pinging
 

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

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...

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

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

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

absolutely!!

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.

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

--DD

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.

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.

Yes, Alfred- You should.

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