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914World.com _ 914World Garage _ 1.7 single carb or 1.8 fi motor

Posted by: jimkelly Jun 22 2005, 06:45 AM

My car has a 1.7 single carb but I have access to a 1.8 fi motor. Should I do a swap when the motor and tranny are out for a clutch replacement??

Posted by: ClayPerrine Jun 22 2005, 06:50 AM

Jim,
The FI will run better and get better mileage than the single weber carb. It will also make the engine last longer. To get a air cooled 914 to run with that carb, you have to run it really rich because the fuel drops out of atomization at the manifold below the carb.

I would put the injection back on. Easy starting, and smoother running.

But remember, I dislike carbs, so my opinion is biased.

Posted by: jimkelly Jun 22 2005, 07:25 AM

Thanks - who is not biased

I've read that FI is much better than carbs for these engines.

I suppose a 1.8 with 50k on it should be better than a 1.7 with unknown mileage as well too?

Jim

Posted by: tat2dphreak Jun 22 2005, 07:44 AM

QUOTE (jimkelly @ Jun 22 2005, 08:25 AM)
Thanks - who is not biased

I've read that FI is much better than carbs for these engines.

I suppose a 1.8 with 50k on it should be better than a 1.7 with unknown mileage as well too?

Jim

if you are REAL energetic, you can take the FI off the 1.8 and use it on the 1.7... don't use a single carb though, 2 carbs or FI, whichever you feel like you can dial in more correctly is the right choice for you...

Posted by: ClayPerrine Jun 22 2005, 08:05 AM

QUOTE (jimkelly @ Jun 22 2005, 07:25 AM)
Thanks - who is not biased

I've read that FI is much better than carbs for these engines.

I suppose a 1.8 with 50k on it should be better than a 1.7 with unknown mileage as well too?

Jim

If you raise the compression, the 1.8 engine is better than the 1.7. The 1.8 uses bigger valves. The problem with it is that the manufacture dropped the compression ratio to lower emissions, so we get a lower HP output. With the tweaking that I did on Betty's car, we get about 90 HP out of a 1.8 with the injection. But it doesn't have the torque of the 2.0.

Wish I could talk her into a built 2.0 for her car.

Posted by: root Jun 22 2005, 09:18 AM

Jim,
Just thinking out loud here.....
This engine comes with fuel injection,right? Does that include all the goodies?
MPS-manifold pressure sensor, brain, wiring harness....
Don't forget you'll need a fuel pump too.
The one you have for your carb won't cut it. You need ~32 psi constant for the F.I.

Maybe ask Boboli914 for a list of what it comes with so you can plan ahead.

Posted by: jimkelly Jun 22 2005, 09:37 AM

Root,

I've contacted him - I'll keep you posted.

That orange car in CA with the fuchs is still avail. I emailed the owner of it too as I will not be satisfied until my car has fuchs on it.

Also there is a guy parting out several cars in the dc area - I emailed him for parking brake handle and cable.

It will be real nice when we have a complete list of what is needed .

Thanks,

Jim

Posted by: tat2dphreak Jun 22 2005, 09:42 AM

not only the fuel pump, but wouldn't you have to change the FI harness and the relay board? since the 1.8 was Ljet? unless the car was originally an Ljet car that is...

Posted by: SLITS Jun 22 2005, 09:51 AM

1.8 was L-Jet....no pressure sensor...metered by a vane airflow unit...you would need EVERYTHING to make it work (or spend a bunch of money acquiring the missing parts).

Posted by: Dave_Darling Jun 22 2005, 09:53 AM

The relay board is the same for L-jet cars as it was for D-jet cars. One single part number is listed for all four-cylinder 914 applications.

--DD

Posted by: jimkelly Jun 22 2005, 10:12 AM

I'm starting to see why people with limited mechanical abilities switched over to carb/s from FI. I guess a comprerssion test on my engine and the 1.8 would yield some valueable info. Maybe the 1.8 carbed might be an option as - for one reason - it has only been sitting for one year and my 1.7 has been sitting for about two. Jim

Posted by: tat2dphreak Jun 22 2005, 10:21 AM

QUOTE (jimkelly @ Jun 22 2005, 11:12 AM)
I'm starting to see why people with limited mechanical abilities switched over to carb/s from FI. I guess a comprerssion test on my engine and the 1.8 would yield some valueable info. Maybe the 1.8 carbed might be an option as - for one reason - it has only been sitting for one year and my 1.7 has been sitting for about two. Jim

single carb should not be an option... sorry, they are terrible... and will not give you enough fuel, you'll run lean all the time

Posted by: root Jun 22 2005, 11:37 AM

Yesterday I looked at Jim's car. I got to tell you that's the first time I've
seen a teener with a single carb. Reminded me of the old old days pre-typeIV.
When the bugs had single carbs. Jim and I were so busy looking at everthing else
we didn't spend time checking the carb out. Don't even know what size it is yet, but
it did look old-old skool cool and simple in there with the chrome air filter and chrome intake tubes ooh yah!.

I suppose if you tuned the thing well and you drove really conservative (like granny-style) you'd end up getting pretty good gas mileage.

I'm thinking that people with 4 cylinders and one well tuned carb should get some kind of Federal Gas Rebate...

Posted by: type47 Jun 22 2005, 07:48 PM

many fuel injection parts for L-jet are still available at a reasonable price, unlike D-jet. i vote for 1.8 L-jet (but i'm partial, i have one w/L-jet). if you are thinking of going that route, consider the porsche parade swap meet this sat, 6/25.