slate blue

By Brendan

Brendan, the springs are Comp Cams 26123 and the retainer is 799. The seat pressure is 90 pounds versus 60 and 252 open @ 0.500'' I plan to drop the seat pressure back a touch and that way I will be at 252 pounds when at 0.515'' lift. The open pressure on the euro we checked was 220 pounds on the intake and 240 pounds on the exhaust.

I have some photos of the differences but they are not developed as yet.

No worries Dr Nick, plan on it, should be a really neat install, the pump is going where the air cond compressor was.

By Brent 89- Gt
Thanks for that info Brent, I do appreciate your feedback, I would love for my car to be 6.3 liters, in this low revving 2 valve guise. The extra capacity just makes things easier to achieve. But an extra 2k for 0.5 liters doesn't add up for this project.

O.k if you have read the first post I do having reduced friction on my side, the other thing is having a MAP sensor versus a carb is a big advantage when it comes to idle quality. I don't think it is a big thing when outright power is concerned with this style of engine. I will also have plenty of compression to try and tame that cam. I have been told I should be at about 12 to 1. Remember our fuel here is 98 octane and the guys doing the heads have impressed on me the need for the high comp and a tight quench.

The cam selection is coming next, I need a cam that will idle with the air on. This will certainly be an interesting part of the project. How does your engine idle Brent? The car I quoted did have a Map sensor so that helps as when you get a carbed engine without a lot of vacuum you get double trouble just because of the way the carbs work.

The last engine these guys did, was a chevy and the heads had a theorectical max power of 580 hp. They got this with a 270 degree cam @0.050'' That is a big cam.

Brent 89-GT

Some of this just comes from picking my engine builders brain. I watched him for a couple of years before I used him though and he seems to be right on.

One intersting comment he made to me having dyno'ed thousands of engines was that as far as static compression goes, either stay around 10:1 or go all the way to 13:1. There is little or no gain from 10-11,12:1 and with 98 octane you might be able to pull off a little more.

My cam specs are 238* @.050 112*LC and .540 lift. The car will idle in gear with a 1800 stall convertor at 8-900 rpm. If I want to run the AC I kick the convertor into high stall (3200 rpm) and it takes enough load off to run the AC at idle too. Most guys can't get this cam to idle well below 1000 rpm. I attribute the gain to sound engine building, the block is zero decked, the chambers are polished and cc'ed, the heads are machined to fit perfectly, there is virtually no gasket sealer or silicone in the engine to make up for anything not fit right. He even spaces the spark plugs so they all face the right way in the chamber.

I would guess that you are having cams ground since the choices are probably slim and none out there. The 112 LC on my cam certainly contributes to the rough idle. I am just guessing as I have no idea how a 928 engine compares in real life set-up to my dinosaur but maybe something like 236*@.050 114 LC and the .515 lift. Your next project after that will be getting the spark timing all figured out. You're going to need a good friend with a chassis dyno

BC

Greg - Thanks for the info on the Springs. You, I assume, did some different things with the retainers? I did Crower springs (they are in my area, so i was able to actually talk to the guys in person). I did some pretty big open pressures, past 270 IIRC. I am a BIT concerned about belt wear, but everything else should be good, and the power increase from a properly and quickly shutting valve is supposed to be noticable at above 6000rpm.

slate blue

Hi Brendan, yes we shall need to share info, this is interesting, did you know with your GTS crank you could turn your 2 valver into a 6.3 liter? I was thinking about seeing if one was available, but for me, to buy one say $1000 then modify it, say another $1000 you may as well buy one straight from Moldex for $2500. But with some mods you should get well over 550 hp. That's not too shabby.

The pistons are cheap and so are the rods and valves, this is the big advantage of the 2 valver. Hope to have some more info soon. If anybody wants a set of performance ground camshafts for the 2 valver I may sell my spare set. I will be sending my lifters over to States tommorow to have them DLC coated by Anatech. For me this is fasicinating stuff.

Cheers Greg

BC

This IS all facinating stuff Greg. The LDC really interests me. I should be getting my 89 5.0 pistons back from Swain with thier new gold coat and PC-9 skirt coating. I'll take pics if I can.

The GTS crank I have packed away is for the "third engine" as it is named in my head. The 78 engine was 4.5, worked heads, new 10:1 Mahl pistons, the original forged rods but redone, and 78 cams. The springs were simply an experiment in NOT paying 100 bucks a spring and getting more pressure for more revs. The head/78 cams (nothing huge as we know - but good)/86 Euro runners and TB, and EFI can hopefully be reved a bit. All I did with the sump was a surge baffle like Louie's.

I'm off focus here - The GTS crank is for a third engine that will be way off stock lines. Hopefully some sort of deck plate (I need to talk to you about yours) and nikasiled bores for JE or similar pistons outside 100 but less then 104 to keep the bore wall thick enough below the deck plate for over 18psi or more. A second set of 89+ heads (larger bolt boses) will need to be puchased, but I already have 85 32V cams.

This means there may eventually be a third 928 for me. I don't know yet.

Good stuff Greg - good for you to do all this stuff and talk about it.

m21sniper

" Of course it only spins 6000 rpm and breathes through a carb but 500 hp from a NA 5.7L anything is stout."

Winston cup....errr....Nextel Cup cars in that displacement range run in the 750-800hp range(non restrictor plate). Of course they get up around 9000r's.

500 is easy from a 5.7 if it's done right and drivability issues are not important to you. Takes a lot of money to get there though...

slate blue

Hi Guys I found that article on the web that was in CarCraft. Here's the link
500 HP 302 Ford
There is a good shot of the beehive springs, although I use different ones. He is using Ti but at 8 grams or so I don't see the point.

Also Brent I thought you may be interested in this article, 539 HP 383 on Pump gas

Brendan I would be interested in what you find with the coatings, I must admit I'm not really following what you are trying to achieve with this 4.5 liter engine. Is it just a rebuild with a bit of attitude and a matter of gaining experience? Nothing wrong with that BTW. Just curious. What about using early Euro cams in it? Also when you say worked heads, what have you had done? Also you know there will be trouble with the oiling of the crank past 6k?

As my heads, the guys want to pull the inserts out of the exhausts, then ceramic coat the exhaust port. I don't know about this? They also want to use stepped headers. Man are they fussy about things.

Also a friend of mine has 4v late model heads, might be for sale too. I have done the 85 86.5 cam conversion, I will post pics when they are developed, damn I wish I had a digital camera! I wouldn't go the nicasil route, not when Mahle are doing great pistons quite cheaply. Also if your engine is boosted, Mahle have already done a piston in 4 inch. Remember the post by Lag. Maybe Mahle can do better than their full custom price given they would have that spec saved.

Brendan I have all but given up on my second super motor, I think 3 motors is too much for anybody isn't it?

Cheers Greg

BC

The 78 was originally meant to be a very well built, but not-too-worked 4.5L for my 78. But it "project creaped" a bit and it will be injected with www.megasquirt.com and have some boost cooled by snow stuff. The engine is already together, ready for wiring. The heads were ported, valves were polished, and the margins were done according to A. Graham bell on intake and exhaust. They were also decked. Which means I spent alot of time and a moderate amount of money on them. No flowbench, as at the time, I was planning less power then I am now.

It was a learning process for me. First engine really done form the ground up. I learned alot, and when I build my semi-stock 89 5.0, I will be a bit better.

That means the third engine (with the GTS crank and 85 cams) will be perfect, right?

The pistons thing is pretty up in the air for the third engine. The reason for nikasil was the range of aftermarket aluminum pistons, and the fact that Mahls are so hard to rwally g et a handle on. I have contacts as JE for 1000 dollar set of 8.

slate blue

Make sure Brendan you get the pistons made in 4032, that way you will be able to run a tight bore clearance Unless it is a big boost application, in which case 2618a may be the go. I suppose what I'm saying is do you homework on the piston material.

Cheers Greg.

slate blue

Hi guys sorry for the poor quality of this photo but I couldn't get it any better, 200 kb isn't much when the doc is scanned it seems.

This graph shows the changes in maximum headflow horsepower figures. The Intakes are standard size, then 2.02'' and 2.08'' The exhaust is standard and 1.65''


The next graph shows the actual CFM rating of the head at different lifts.

The head really takes off on the higher lifts, I think they said it would flow 630 hp at 0.700 lift. Again sorry for the poor scan quality but I can assure you I tried my best.

Vilhuer

Greg, convert them to gif and then downsize to 200kb. Quality is much better for same size. Works for all line drawings etc where most of the area is single color backround.

slate blue

My scanner doesn't have GIF unforntunately.

Vilhuer

No problem. Scan it in high quality jpg. When you have them saved at disk drive, open them with some picture editing software and save in appropriate sized gif.

slate blue

Here's a photo of my new valvetrain, the intake will be bigger at 2.08"


Also just in case somebody was interested here's the under side of my slipper pistons.



Cheers Greg

BC

Thanks for sharing Greg. I found out yesterday that a stock 32V S4 head will flow 300cfm. At what lift and what port velocity it is I don't know.