heinrich

As part of my S4 Supermodel conversion I will be left with a spare S4 engine. Now I'm thinking long-term but my '85 will be a quite happy recipient of some of those engine parts. Obviously the '85 pistons with the S4 heads would yield better compression, so that looks like a worthy project, installing the S4 heads. However, I'm wondering what parts from each I should use. I'm thinking:

'85 block (leave it in there, just remove heads)
S4 heads
'85 cams (ground off)
S4 intake with flappy deleted
grind '85 intake bracket off the valley if necessary
S4 throttle assembly (it will be spare anyway after the S4 gets the SC)

What think you all? Again ... way long-term. The '85 is like new, and the engine has been exercised daily but babied.

hacker-pschorr

Damn, I was doing research on similar projects.

I'm either going with a 4.7 or 5.0 lower end to mate up with a set of Euro heads, Cams, and Intake. My end result will be supercharged, (ala Mr. Murphy's suprshark route). Let me know if you have any parts left over!

sharkmeister85

H,
It was great finally meeting you and the others( John, Ken, Shane) on the weekend. Much too short of a visit though! Next time we meet, I hope it will be in your "back yard". Anyhow, to the purpose of this thread. To what ends are you trying to achieve by putting together a hybrid?
Glenn

heinrich

Absolutely likewise Glenn and MAN was that some a$$-kickin' fun drive ...

I want to use the best parts of the 2 engines to make more power. I've historically made 299bhp to the rear wheels in the S4, so I'd like to use some of that goodness to help my sweet little 85 along too. Since I will have the spare parts, I figure why not!

All the best, and btw I've put together a drive this weekend if you can make it
Heinrich

heinrich

Hacker I surely will keep you in mind

Rich9928p

S4 intake with flappy deleted

Why delete the resonance valve? The chart shows what the valve does for performance. The second chart shows what the LH controller does, you would replace the LH logic.

What you could do is put in a manual linkage from the resonance valve to an actuator. Use an inside switch to control a relay that powers a solenoid and manually control the open and close. For normal use it would stay closed and when you're looking for power switch the flappy open above 3600 RPM.

heinrich

Rich, true, especially on an auto. Regular driving could keep the flap closed and just open it manually if i want to drive in "performance mode" ... great idea.

heinrich

Hahaha .. how about connect the flappy to the kickdown!!!!!!

drnick

i thought the S4 heads yielded a compression ratio of more than 12:1 with the 85/86 block? or is that the other way around?? i cant remember...

sharkmeister85

I guess I don't really see the point. You're going to have real ***-kicking power in the S/C S4 when you're in the mood for such ( which for me would be ALWAYS). So anything you do to the 85 won't compare for power anyways. All you'll have then are some odd parts left over from the 85 and the S4 and 2 "bastardized" sharks. I would keep the 85 stock and reliable, and save the spare S4 engine for the day you blow up the S/C 'd one. Which you know is inevitable ("power corrupts and absolute power blows engines absolutely" or something like that ) My 2 cents, not figuring exchange.
Glenn

bcdavis

Not a bad idea...
Keep the 85 stock, and use the other extra parts to build a *replacement* engine for your SC928 engine.
Then, you'll have a sturdy, low-compression engine ready to go...

heinrich

There are several things I don't like on the S as opposed to the S4. The humungous intake is in the way; the intakes are teeny; there are so many little tubes, connectors and schtuff up front that i get dizzy looking at it. The S4 intake is so much cleaner. Well ... as I say it's LT, so for now she'll stay stock so I have a 928 to drive while White Lightning (I think I just named my car) is in surgery. And anyone who knows me, knows that may be a while.

BC

How much would you want for that 87 bottom end?

hacker-pschorr

Get in line -

BC

Nice Hacker. He's in seattle - if there IS a line, I am closer.