Vilhuer

This is interesting point as I think its impossible as heads are basically same.

hacker-pschorr

One way to find out - is the 944 cam tower a 928 part number?

Vilhuer

No, it starts with 944 as does heads part number. But it doesn't mean valves are in different position than in 928. Cam can also be longer at front end while area above valves is same.

danglerb

If the cast "core" starts as round lobes, wouldn't it be better than welding up a used cam? If it wasn't a round lobe core, correct it would be pointless.

Also right now I am going from a casual email from one cam grinder that 31 rwhp beyond the Euro S cam is possible. Cam guys are NOT chatty types when it comes to details either. I am hoping to pry a bit more info out of him later on since he is part of some event with Don Glidden later this month I think.

Cam guys must have some kind of software that models the piston etc. and shows what can be done with X amount of cutting in the pistons.

John Veninger

He didn't tell you about the $5K+ worth of head work need to allow his cams to make that additional 31 rwhp over the EuroS cams

hacker-pschorr

How about the intake? The EuroS is the most popular for 16V N/A engines. That does not mean it's perfect. Sure it supports 310hp just fine - what are the limits? Will they flow enough even with good cams & head work to feed the engine?
People tend to overlook the intake manifold's on these cars when trying to make N/A HP. What do all of the high HP N/A 928 engines have in common? Custom intakes.
Your car (and Louie's) Devek's ITB setup, Mark Anderson's carbon intake etc...

dangle,
If you are serious about this project, why not invest in a stand alone engine management system and individual throttle bodies?
You seam to think we are strying to squash your idea's - just the opposite. Many of us have seen other people do exactly what you are talking about doing - with mixed results since giong the full monty (head work, custom intake etc..) is beyond the limit of where most people will take a 16V.

You should chat with Greg Ray down under. He is building what I'm sure will be the most powerful N/A 16V known to Rennlist (yes I know the HP claims of some early DEVEK motors, doesn anyone know where these are?). He has an individual throttle body setup for his 16V stroker motor.

danglerb

What kind of an "colorful name for person" would buy an 84 and be unhappy with better than Euro S HP in a package that easily passes smog?

OTOH if I bought a car and found out "later" that it had some blower kit on it, I would not be too happy about it.

danglerb

I live in the Peoples Republic of California, there is a limit to what might sneak through the smog inspection.

This is less an exercise in pushing the envelope, more of a WYIT, if I could get a set of custom ground cams with even marginally better performance than the Euro S for say $500 each as brand new cams, thats worth a touch of rolling the dice. The garden variety of Euro hybrid sounds like it will have plenty of HP to suit me.

I think the "main" weakness of the 16v isn't the flow in the head, at least at the power level we are talking about, its lack of a dual runner system with narrow intake tubes to boost low end torque, like flappy in later models.

My personal guess is that many of us will be going to aftermarket ECM over the next 10 years as more powerful generic units become available, but my first choice for now is to change nothing, keep it L Jetronic and cheap.

John Veninger

I've been told 400hp for the EuroS w/CIS.

danglerb

Thats ballpark of what we are talking about 320 rwhp, but sounds like its ok.

I am kind of curious why they should flow that well, 30% over stock HP, since it must reduce the velocity and torque at lower RPM.

Given the style of the early intakes would it be that hard to fabricate something in tubing to replace the runners? Just tell the smog guy its polished to make it shiny. BTW as I write this I can see it getting me into nothing but trouble.

John Veninger

My old 5.0L CIS motor made 305rwhp and 320 ft-lbs using stock EuroS stuff and free flowing exhaust.

Shane

Back when you were shopping for a 928, I suggested you might look at the '86.5. Now here you are looking for more HP and your target is right where a '86.5 would have put you. Mine with just a set of chips, nothing else, put down 281rwhp. Now a couple years later, I have fixed vacuum leaks, resealed my intake, ditch a bunch of smog crap, added an electric cooling fan in place of the belt driven one, put an x-pipe on, and a whole host of other goodies... well it is time to redyno, quite likely it will come in right around 300rwhp. No cam changes, no blower or turbo or LT-1 or stroker build, just got it running right on AA chips and a real nice exhaust system. It is a very fun car to drive!!

hacker-pschorr

"that hard" is a tricky question. Do you want to retain access to the spark plugs? Injectors? Where do you want your torque curve, power peak? Sure any welder can make a "better" intake - what is the end result going to be?

For the absolute most power you want the shortest runners possible (see the ITB like I mentioned before). For a street car this may not be ideal, where is the best balance?

danglerb

Shane you have convinced me, yes I want a 85/86, ... shortblock, just not the rest.

When I am all done I may sit down and count all the beans and see how many go in each pile. Truth is if I found the right deal on a later model car tomorrow I might buy it and keep my 83 closer to stock. BUT this is the car I have now, and the best I have found so far for me, so I will continue to work on making it exactly what I want until another path presents itself or I finish.

Fabricate, but nothing fancy in mind, duplicate more or less the existing 8 runners in a larger ID via tubing with thinner walls, or less bends, but chances are MUCH higher that I would just use the Euro intake.

Imo000

No disrespect but throwing words around like “simply, fabricate and just” usually in the same sentence should not come from someone that doesn’t have experience in this. You said it yourself that besides a basic tune up, you are not comfortable to do any other work on the 928 and rely on a pro. There is nothing simple or easy in building a custom intake manifold. It might appear that way but I bet it will take some trial and error to get one right. Imagine all the money and time it will cost to make this “simple” intake.

Drive your ‘84 for a bit, then decide if it needs any upgrades. I’m starting to think that perhaps you bought the wrong model/year 928. Were you dissatisfied with all your previous cars too or just with this 928?