Corvair abomination contd.

mike95125 · 01-24-2003, 05:40 PM

Well I just ordered 6 pistons, cylinders, rings, pins, and retainers for my conversion and it cost $238.50! They are Mahle type 1 94mm X 82mm stroke. I will be machining off .300 inches from the bottom end to accomodate the cranks stroke, but they will require little else to work.
Also, today I have just recieved my catalogs for parts, and have some figures for those interested.

-Reverse cam $227.00 with new pressed on cam gear ( I could also have the old one reversed for $90, but I want a new one)

-Reverse gears for distributor, and oil pump $96.80

-I got some ballanced, pollished, magnafluxed rods off of ebay for $110 ( another not too necessary expence, but worth it)

-I also have two adapter plates now that I got off of ebay for arround $120 each, the second is better, but the first came with a flywheel worth $220. These will be for sale soon as I only need one.

-One dirt clod of an engine for $50. If the case turns out to be shot I can purchase another in better repair for $25 +1.25 shipping. Hows that for value!

I may just adapt the 914 D-jet to run six injectores as I see this is the least expensive, easiest, purist way to go. Ill still need to fabricate down tubes, and an intake plenum, but I think that is doable.

Questions, comments, ideas Im listening

John Rogers · 01-24-2003, 07:59 PM

Why not a K-Jet from a 6? Will it be done by the next gettogether at Herb's resturante???Good luck.

mike95125 · 01-24-2003, 08:33 PM

I dunno, why not K-jet. Proly caus I dunno what it is, tell me more.
As far as for Herbs next shindig, I doubt it. I will need to get money together, and school has started and is getting in the way of my hobby. Damn school.

sammyg2 · 01-25-2003, 08:23 AM

Yup, Iffn I were doing it (and I'm not) I would use a CIS system from a six. They are cheap and work well. The hardest part would be the fuel lines and pump, but that can't be that hard.

HMeeder · HMeeder's Garage

Continuous Injection System (or K-jet) could be a very good possibility for you Mike. The system runs continuous fuel pressure that is distributed to the individual injectors via a fuel distributor metered by a air flow sensor which is a plate on a swing arm in the intake flow.

This system was used on 911s in the '70s and '80s (and lots of other european cars, 4, 6 and even 8 cylinders. Several Marcedes models and the 928) I bet there may be some useful info over on the 911 tech pages and BBS.

I also have Ben Watson's Bosch Fuel Injection book which explains the funtioning of CIS and has many useful tables for various applications. Give me a Ringy Dingy. I'd be happy to loan it to you.

mike95125 · 01-25-2003, 06:25 PM

Ahh! K-jet = CIS, I didnt know. Thanks, I'll have to take you up on that Herb.

John Rogers · 01-25-2003, 07:51 PM

We have the K-Jet (CIS) system on our 1987 Turbo and it is pretty easy to setup and work with. The biggest concern I have is the fuel pressure which runs about 75 PSI or so! There are also dual fuel pumps which are in series to run the pressure up that high. I imagine you would need to replumb the old 914 fuel sytem. Look for Volvo or Saab sites as they used it a lot. Good luck.

Speedo959 · 01-26-2003, 07:10 AM

Ok reading this sparked a question. What about converting a 70 T from Zeniths to CIS? Is that an upgrade or downgrade?

sammyg2 · 01-26-2003, 08:43 AM

Going from zeniths to CIS an upgrade in driveability and reliability, but may be a downgrade in performance. Biggest problem is that the CIS system doesn't like high overlap cams, kinda like D-jet. CIS uses air flow to meter fuel and at idle the flow would be erratic with a big cam and so would be the fuel metering.
I dullo what kind of cams are in that 70T, but I would check them against a CIS cam before spending any cash on it.

BTW, the K-jetronic systems on turbos do have two fuel pumps but the N/A systems only have one. Fuel pressure is still high but the flow rate doesn't need to be as extreme.

mike95125 · 01-26-2003, 10:55 AM

The main thing that I have found on the net is that the CIS needs around 76# of pressure, and the whole setup is large, ans cumbersome. This is as reported by an article I found by someone doing a similar adaptaion on a plane with a corv engine.
I have concerns on which cam to get, and I know that the main parts supplier will most likely know which will be the best. My guess is the one that I am looking at, which developes its torq from 2500-5000 rpm, will likely be the best condidate, but they can custome make any profile I require, and they have a proven FI set up. I'll be getting the list of parts for their FI set up in the mail with instructions on how to do it. I'll keep yall apraised.
Thanks,
Mike

RarlyL8 · RarlyL8's Garage

What you plan to use the car for and how much you wish to spend will dictate the fuel system you choose.

I would not use CIS on any engine that was not built for it.
Many reasons:
- CIS requires specific piston dome shapes
- CIS requires specific cam profiles
- CIS is a smog system that does not produce optimum power (see above requirements)
- CIS is not efficient by modern standards.

So what to use?

EFI.

It is simpler and fully tunable. Will cost more to put a system together but will be more drivable, have sharper throttle response, and better fuel mileage than CIS.

Carbs will give you throttle response and more power than CIS, lousy fuel mileage, and finicky drivability. But, they are simple and cheap.

red-beard · red-beard's Garage

Mike - I have a Porsche 6 cylinder CIS setup in boxes, around here someplace....If you want to try to use it, we can work something out.

However - The "magic" to the CIS setup is the airflow plate. This is not just a flat disc, but is actually "tuned" in it's dimensions to the engine. This is the main reason I have not removed the Carbs from my 6 and replaced it with the CIS as I had intended. I _KNOW_ that the cams on the engine were upgraded to "S" cams when the displacement was upped from 2.0 to 2.2. It's an MFI cam. So, the 2.4 CIS probably will not work with the engine, or at least not well.

If I go CIS or anything, it will be by either going EFI or doing a complete swap for a 2.7 which already has CIS.

James

mike95125 · 01-26-2003, 01:47 PM

James: Thanks as usual, but I just got someone to sell me a Mega Squirt board. Yippie!!!!
CIS scares me. I like EFI, so MS is great fro my abilities.
RarelyL: Thanks for the augmented info, it re affirms my CIS=voodoo stance. This is just my personal preferance so yall put the torches away. Im sure CIS is great, if your into that sort of thing

jkeyzer · jkeyzer's Garage

MFI S-cams have a lot of overlap which causes low vacuum and backwards pulsing in the intakes. Everything I have read says CIS can't handle this. I don't think I would ever put CIS on any motor that didn't already have it!

Bruce Allert · 02-02-2003, 10:08 AM

Whilst peruzing old mags from the back of "The Throne" I ran across this letter to the Techs of Road & Track from their August 02 issue. I found it quite interesting after reading what you are planning to do. Maybe you could do the same with less hassle???

bruce

mike95125 · 02-02-2003, 10:37 AM

Neet! I just picked up the choicest engine yesterday. Its already apart. Truly if you wanted to just bolt in 140hp you could just buy a corvair engine ($300-500), and reverse the rotation(cam regrind = $90, dist/oil pump gear = $90), and get an adapter ($100-400). I already have most of this stuff, but I am gonna go a bit further.
Thanks for the post.