[jpavlack]

I will be getting my hands on a '75 Ascona shortly. I also have a killer motor that I'm dying to use. It's a Tom Thevenin built European 2.0 with the 2.2 crank. Head is the middle model 1.9 hydraulic lifter head with stage II cam(286 duration, 420 lift). Will this work with the fuel injection or should I ditch it all and put in a 38 dgas Weber? By the way, it is an automatic transmission. I obviously don't know anything about fuel injection, can somebody help me out here?

 

[RallyBob]

Joe, do you have any more specs on the cam? If you can provide the duration @ .050", and the lobe separation angle, that would help out. Stock Opel EFI doesn't like a lot of overlap and duration. I've found that it's usually better to keep the duration @ .050" below 220 degrees or so, after that the air flow meter tends to bounce around due to pulsations in the inlet tract, and off-idle performance is will be bad.

I don't see anything else with that combo that would hurt the usage of EFI, in fact the larger displacement will help to keep the idle vacuum decent.

Bob

 

[jpavlack]

I'm afraid I don't. All I can tell you is that it uses stock valve springs but they have been shimed up .050. I'm reading the specs as Tom wrote them in 1997 and I don't see anything that might help. You probably know that he passed away some time ago before he finished this motor so it would be very sentimental for me to finish it since I considered him my friend. According to Toby all it needs is for the pistons to be fly cut.

 

[RallyBob]

Joe, are there any numbers engraved into the front of the cam? If you could find out who used to grind the cams for Opel Parts and Service, any numbers might ID the cam for you. Do you still keep in touch with Toby Thevenin? I believe Charles Goin said he still spoke with him on occasion.

HTH
Bob

 

[davegt27]

go FI just jump in with both feet

in six months you will be an expert


davegt27

 

[jpavlack]

I will try to reach Toby about the specs on the cam. If it were compatible, would you pick fuel injection over 38 dgas? All things equal, which would perform better?

 

[RallyBob]

I will try to reach Toby about the specs on the cam. If it were compatible, would you pick fuel injection over 38 dgas? All things equal, which would perform better?

My personal picks....

1) Programmable EFI, using stock Opel EFI intake, but no air flow meter used. Best overall for power/torque, and tunability. Limited to about 160 hp with stock injectors.
2) 38 DGAS on ported intake. Easiest to setup. Easiest to service. Good power still, but not as much as the programmable EFI.
3) Stock Opel L-Jetronic fuel injection. Can be problematic, if a part 'lets go' on a road trip, finding a way home may be difficult! Will have good power in the mid-range, but off-idle performance with a big cam can be shaky at best, and top end power may suffer due to leaning out of air-fuel mixture. Limited tuning capabilities. Usually, any mods that affect one area of the power band will affect all areas of the power band. Make it richer at 6000 rpm, it'll also be rich at 4000 rpm, at 2000, etc.

Your results may vary....

Bob

 

[jpavlack]

thanks Bob,
I'm going to give the FI a try but looks like I will go back to the 38 dgas. I just don't have the knowledge or equipment to install a programmable fuel injection kit. Maybe someone will have such a thing at Carlisle next month.
It's just a shame to go from FI back to carb in an original '75.

Joe

 

[davegt27]

yeah on the stock 75 FI the motor needs to be in good condition

if you have any doubt go with carbs

i had a guy with a 75 wagon tell me that a 260Z ECU will work in an Opel

never tried it

But keep that in mind when looking for parts.

davegt27