Finally driving again!, Type IV CIS conversion Options

[VaccaRabite]

Jake is your carb cam (the one similar to the 494) too aggressive for CIS?
Zach

After years of working CIS on other engines, I suspect it is. If the cam gets too agressive, the air lever in the fuel dizzy starts to move erratically. In theory, this can be abated by adding anti revision geometry to the intake track, but I've never tried it/seen it. I've only read about it from some of the ancient notes from Drake Engineering. That said, as you increase air velocity, cam becomes less and less important. I've run rabbit 8v engines well over 200hp on CIS. In that environment we could get away with cams that simply wouldn't work at lower air flow.

I've seen CIS come up a lot lately, is there something in the air? Anyone ever thought of going digifant? Digifant I lends itself easily to an engine like the type iv.

The 9530 cam that I have is supposed to run well with CIS. Jake says that he has used it for CIS engines in the past.

That said, I'm going to MSII.

Zach

[Dr Evil]

Zach, for you I would gladly assemble a MSII for free (IMG:style_emoticons/default/smile.gif)

[HAM Inc]

As for what happens with a radical cam with the CIS, I can't speak to how a T4 would act with one, but I can say that my dad raced a circle track 1.8 rabbit with CIS.

The class limited lift to .425" but had no limits on duration or LC. He ran a seriously radical cam with lots of overlap. He also had 14.0:1 compression. It was actually very drivable at lower revs (which it only saw driving around the pits and onto the trailer), and was unbelievable strong on the track (he won a lot of races with it). It idled great with a little lope, but it never bucked and throttle response was instant, even when heavily loaded.

It surprised us both how well the CIS handled the overlap. Of course I'm sure the compression helped and if it had been a street car (with lower compression) it might not have been as tame, and the myriad driving situations that come up on the street might have revealed some shortcomings. But I have driven carbed engines with a lot of cam on the street that were much less behaved.
To bad it's such a PITA to change cams in a T4. It would be pretty cool to see how one responded with a lot of cam. I suspect that the lighter 914 would be more forgiving to it than a heavy bus. I also thing that a larger engine would handle the CIS with more cam better.

[dlee6204]

Small Update:

I've been driving the car alot and it hasn't missed a beat. Last weekend I took it to the mountains and drove to the top of Mt. Mitchell (6500 ft) without a problem. Today I took it on a charity car cruise through some hills and lots of back roads. Over 200 miles today and I got 31 MPG! That's pretty good considering I was driving it pretty hard at times. I have been getting about the same with mixed driving around town. I'm pretty pleased with these result. I think I'll keep it. (IMG:style_emoticons/default/smile.gif)

[jaxdream]

Most Excellllent (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/piratenanner.gif) !!!!!

Jack

[SirAndy]

Most Excellllent (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/piratenanner.gif) !!!!!

(IMG:style_emoticons/default/agree.gif)

[VaccaRabite]

That GREAT!
Zach

[dlee6204]

So I thought I would give one last quick update... The car has been performing flawlessly. It hasn't missed a beat. Still getting mid 30's for mileage and still very pleased with everything. Now that its gotten cold though, it can be difficult to start but that's simply because I never installed the cold start injector and thermo switch initially. That's on the project list for this weekend (IMG:style_emoticons/default/smile.gif)

[Dr Evil]

How cold? The cold start injector does not fire until in the 30s F*.

[76-914]

Doug, what do you think is a fair price for this setup (sans injector brackets) for a guy to pay? I can't help but think one might be better off buying a clunker. My neighbor can't get rid of his rabbit for $500.

[dlee6204]

How cold? The cold start injector does not fire until in the 30s F*.

I know the cold start injector fires around 32 for a D-jet system but is that the case with a CIS Basic system? It depends on the Thermo-time switch which I believe is different.

Usually its hard to start when its in the 30s... maybe 40s

[dlee6204]

Doug, what do you think is a fair price for this setup (sans injector brackets) for a guy to pay? I can't help but think one might be better off buying a clunker. My neighbor can't get rid of his rabbit for $500.

I would say you could get most of the components for $100-200. I know I paid less than 150 for everything from the local pick-n-pull

[pete-stevers]

i hope to build out my next 914 with a cis 1.7...rather than a six, primarily for milage over brute hp

[Dion]

Doug,

Nice build. I have the CIS on my 2.0. It worked so well this past summer I wound up blowing 1st gear(40 yrs old,never touched)with the improved torque.
I was wanting to dyno it before this mishap. On paper it should be in the 120hp range. It has 96mm P&C with a FAT cam lift 413, and duration of 258.

I had posted my build titled "16 mos in the making" or search under Dion.

I received a lot of nice feedback from the forum.

914Dave and I installed it. We placed the airbox on the drivers side with a short run
to the thottle for better response. The Volvo box looks like a good idea. I have the Rabbit/GTI box.

Nice fuel economy numbers you have. We'll back to taking the tranny out....

Cheers,Dion

[trojanhorsepower]

Hey Doug,

Looks good.

Glad you got it worked out.

-Peter

[Jeffs9146]

The Volvo box looks like a good idea.

I used the Volvo box in my 3.0L 6 conversion and it works great!!

[Kraftwerk]

Dion,
I like that set up, and a very clean install.
I used to own an '86 V-Dub, so it all looks very familiar &
very tempting, but my f.i. system works flawlessly right now.

[nein14]

The Volvo box looks like a good idea.

I used the Volvo box in my 3.0L 6 conversion and it works great!!

I have this set. Up in my 2.0 turbo

[type47]

So, how did you guys transition from the boot on the intake air sensor to the throttle body? This pic looks like black ABS pipe

but I can't, yet, find a good way to get to the throttle body. I'm trying to get to a 2L throttle body in pic below:

The mixture system is not in final position for installation; this is to hopefully see if I/we can get the motor running out of the car.

2 more questions:

Do you have "stock" fuel lines or SS fuel lines? Any problems with adequate flow of fuel thru the lines to the fuel distributor?

What initial adjustments were needed to make the system run on a motor? Was it just bolted on and it ran?

[dlee6204]

I ended up switching to a 2.0L intake and Throttle body so I made a special elbow to connect the two. Lets see if I can find a pic...