Will FI work here?

[bigboremike]

hey everyone,
my engine is finally built and im going to spend the winter putting it in the car and getting everything perfect for next spring, so i have some time to decide on whether to use fuel injection or carbs, my engine is not stock, but pretty close, i have an 86 webcam, 96mm P&C's stock 2 litre crank (71mm)and stock 1.7 litre heads(ported and polished), and i was wondering which fuel injection (stock 914) or aftermarket would work with my system and still give me the HP and performance that my dual 40 webers will, any help would be great as i would love to use the FI just cause i dont want to be fussing with carbs when i could be driving! If anyone has a similar setup to what im looking for i would really appreciate your help. Thanks again
-Mike

[John Rogers]

I'd stay with carbs since you already have them. Get them overhauled then jetted correctly on a dyno if possible and you should not have to "fiddle" with them at all as long as you drive the car regularly so the goop doesn't form inside from the terrible gas we have now. If the carbs won't stay adjusted, they may be shot from corrosion/ wear/etc and new ones would be required. Good luck.

[iustasail]

Stock fuel injection needs stock cam, so thats out!

The CBPerformance Type setup will work well
but is expensive.

Carbs are the low cost option of choice; hence so many people use them.

Motec would be cool

[Steve M]

I've got a 2.0 with stock FI, I went FROM carbs to FI. Some people find it easier to deal with carbs, I dont even know how to adjust a carb.
Once I got it running right, FI is a pleasure to have. Granted it did have it's teething problems in the beginning and there were times when the car wouldnt start because a sensor had become disconnected. But since I now know what the cause was, if I ever have trouble starting the car I know exactly where to look. However if your cam is THAT much different from stock then you should stick with carbs. I have a slightly hotter cam on my car and had head work done on it. The FI works just fine and I can adjust the manifold pressure sensor. I've heard claims of 125 horses or more with dual carbs. People say they get more HP out of carbs. I've done 0-60 in around 6 seconds with my car had it up to 120 and the car still had steam. It was expensive for me to get back to FI but that was because I chose to buy alot of brand NEW components and not used. My reasoning to go back to FI was this.
I dont know how to adjust a carb nor do I even care because about 99.9% of autos are FI today. I also have a Volvo 240 and I feel confident in working on that cars FI from the knowledge I've gained rebuilding mine.
However all bets will probably be off if I ever decide to go with a 6 converstion, on the other hand of that I would strongly consider some sort of FI for that type of thing as well.
The 914 came with FI from the factory and I didnt want to have to deal with guess work in adjustment, I just wanted to pick up a manual and fix it.
I get a kick when I tell people the car is a 1973 AND it has FI, after I've spanked a rice burner.

In one case, the vacum hoses, caused me no end of trouble. It literally took me 2 years to figure that out. On the other hand of that argument I was rebuilding not adjusting at that point. You probably want to stick with carb if your cams are that wild. I dont know cams to the extent of the numbers. I know cams to the extent of their function and their degrees. When I had the engine rebuilt I told them just give me whatever would give me the best performance and works best with FI.
If you want to know more about what I did to my engine you can do a search on my name. I've spoken plenty of times about how much I love my engine and FI and blah blah blah.



[This message has been edited by Steve M (edited 09-29-2000).]

[This message has been edited by Steve M (edited 09-29-2000).]

[JP Noonan]

I've been told it is the difference in duration and overlap that throws FI off, if the duration is about the same and only the lift is a little higher FI should work.

Duration and over-lap cause lower vacuum and can cause intake gasses to be blown back into the intake. Carbs handle this fine, the turbulence helps keep the fuel in suspention. FI can't cope because intake air volume is inferred by engine vacuum.

How much is too much, I dunno. Ask the cam manufacture.

BTW did you put bigger valves in the heads?

[Bleyseng]

I think that you should look at changing the small valves in those 1700 heads to atleast 42x36 to get better flow and hp. I agree with John Rogers about the carbs, if you already have them use em. But go to a dyno shop and have the carbs tuned! I see you live in the Midwest so I also have to agree with Steve M that for a car that just runs and runs wonderfully go FI! I put FI back on my 2.0L after running Dell's for 2 years. I also rebuilt the engine with 96mmP&C's, 42x38 valves, ported and polished,CW crank, balanced the engine. Now, I still haven't tuned the FI other than by ear. It dyno's out at 91hp and 108ft lbs of torque at 4500rpm's at the rear wheels. That's also running 2.0L SSI heat exchangers and a stock 2.0l muffler. The car is quiet! NO damn carb noise right in your ear! I can hear the stereo and tons of power for street driving. Other local 914 guys have driven this car and say "Now that's a 2.0l! What did you do to it!"
I think carbs are the way to go IF the engine is wild enough, say a 2.4L with mid to wild cam but that's more for auto x. Porsche put it on the cars for a reason, it's simple and it works very well! Nuff said! Geoff

[bigboremike]

JP-
no, the valves in my 1700 heads are stock.