slate blue

Hi to all, before we call it a day on the development of the 2 valve head, we have obtained 270 cfm @0.515'' lift on the intake, the exhaust should be 80% of that. It has been a lot of work, read $$$$, but we would need more lift to get more flow. At 0.700 it flows more than 650 hp. FYI 270 cfm is 555 hp. I got to say it is a little disapointing. If anybody knows something I don't know and wishes to share it please tell me now or forever hold your peace.

Maybe the engine will make it max hp because the engine is a friction reduced one. It will also have 11 to 1 compression or a touch more. We have genuine 98 octane fuel here in Oz and I was reading that the current F1 fuel is 99% the same as what we have on sale here. So that is pretty good.

Friction reducing and weight techniques employed are; Honda rods, DLC lifters, Lift weight valves and springs, Barnes 4 stage dry sump pump, Crank scrapers, (that I will purchase through the Rennlist) Mahle slipper pistons, with the low friction alusil bore. Block bored with deck plates. Also we should remember that the cam belt is lower friction than a chain. Robert Yates Racing modify their engines to use belts to save on friction.

In the end I am confident that I will have in excess of 500 hp at the crank. This is about the same as the LS7, that can't be too bad. I will just need to loose some weight to make this car really impressive. The exhaust weighs 40 kgs, that seems a good place to start.

Cheers to all

Greg

FBIII

Greg, have been keenly following your development of the 2 valver and your quest for hp. It seems that .515 lift for a 2 valve engine is pretty tame. Have you already already gotten your cams? If not why not run more lift. If your running out of lift based on the stock base circle, why not cut the base circle slightly and run lash caps? What kind of theoretical numbers do you get with .550 - .575 lift?

Imo000

How fast are you designing the engine to spin to produce 500hp?

IcemanG17

Greg
Also what is the displacement of the engine....I'm guessing it is not the standard Euro 4.7L anymore....probably a stroker closer to 5.7L?
Brian

Mark Anderson

I don't know if this is of any help but here are the numbers off my 4 valve heads.

lift intake port velocity exhaust port velocity

100 102.8 76.4 94.8 131
200 204.3 151.8 173.9 207
300 288.2 214.1 236.2 281
400 330.5 245.6 247 294
500 350.4 260.3 250 298
600 354.2 263.2 252.4 301


stock head was 274 cfm at .500
all measurements done at 28"

slate blue

Hi Mark, thanks for those figures I think the only part that is applicable to me is that fact I have managed to get close to the STOCK 4 valve flow figures. Hey, high five me everyone. I sort of knew that is probably where I would come out. Still not happy though. Yes those figures for your heads are great and that was the engine I was planning on building, with a few special mods thrown in.

IcemanG17, as the crank is not ground as yet I can say exactly but 5785 cc is where we are aiming to be. That is 4.060 bore and 3.410 stroke.

Imo000 the engine will spin to 7500 rpm if I don't increase the lift past 0.515'' The bottom end could take 9300 rpm, how do I know, they are Nascar parts.

FBIII, well if you increase the lift into the range you mention, you would be around 580 hp, the problem with more lift is that it will muck me up with the valve spring and pressures required to control the valves. My new springs weigh half of what the old Porsche springs weigh and have an extra 10 pounds or so spring pressure. I believe this to be just enough to control the lighter valvetrain at higher rpms. Also remember the timing belt, I don't want to introduce a problem in that area.

The other thing that has cropped up is the fact the throttles I bought are too small. It hasn't been finalized as yet but a modified version of the existing intake is now a candidate. Shorter and bigger diameter intake runners, which is all the Carrera GT uses btw. This is not too bad as I will be able to ultilize lots of stock components, I may also be able to use an electronic throttle from the LS1. As the throttle body will need to be bigger. I suppose in a way that is a positive development.

Cheers Greg

FBIII

Greg, you might want to contact Devek and see if they have the figures on the heads that were on Devore's 700+ hp engine. Worth a try. If they do you'll have a good idea where you stand in relation to that engine.

slate blue

I think Marc would have posted something if he wanted to, that engine only produced that power when it was over revved. I think the normal power was more like 580 chp. If he had bigger cams than me, that is why he got the higher figure. I have also tried the bigger 2.08'' intake and that didn't help flow either. Also that Bob Devore engine had a greater engine capacity from memory, anybody remember what it was? The greater capacity helps extract the last bits of power from the heads by pulling a bigger vacuum.

Cheers Greg

Normy

A 2 valve naturally aspirated motor that theoretically makes 555 horsepower!

[theoretically]

-Suck it up "boostards"! Lagavulin's car only managed 513 hp with 11 psi of boost- dentonating all the way. Though I TOTALLY support Paul's efforts...I've stated it before and I'm stating it again: There's no replacement for displacement!

N!

slate blue

O.K here's some more data that you guys might find interesting or useful.


Now the heads that are in that graph were featured in a Car Craft Article and they were put on a 302 Ford engine. The reason I have provided a graph to these heads is that mine flow a touch better and as such can be expected to atleast equal the results of the 302 Ford.

The 302 Ford did use cams that gave it 0.600'' lift whereas mine are only 0.515''. At these figures the flow is basically the same. Both heads use the same size valves, except the stems on mine are thinner. The 302 Ford uses a 10.2 Comp ratio, I will have atleast another point but 10.2 may be good in the U.S with the lower octane fuel.

The cam that was used in the Ford was 244 degrees @.050'' and lift at the valve was 0.600" The Ford had a custom intake and used 1 3/4 inch headers. The engine had a tuneable FAST engine control unit and 36lb injectors.

Here's the dyno results


RPM TQ HP
4,600 382 335
4,800 389 356
5,000 391 373
5,200 393 389
5,400 394 406
5,600 398 424
5,800 396 438
6,000 399 456
6,200 401 473
6,400 401 489
6,600 396 498
6,800 391 507
7,000 382 510
7,200 372 510
7,400 353 498
Peak 403 512

All of this from a 302 Ford with the same breathing capacity of our 2 valvers. This is why I believe it will be possible to get Low 500 hp from my engine given if has 351 cubic inch capacity and and a dry sump. Also lots of other little goodies.

Given this engine is not a mega buck deal, I hope others may be interested and follow the same route if it is successfull. I will publish all the details of the engine and where to get the parts when it is finished. While this engine won't cost what a 4 valve stroker costs it would cost more than a supercharger kit.

Here's a short summary of what I have bought * and what I plan on purchasing.
Squirter Block* $200 Second hand needed work
Mahle pistons* $900 New
Lentz Rods* $250 Second hand (Perfect order)
Barnes dry sump* $415 Second hand (Perfect order)
XRP Hoses* $200 Second hand (Perfect order)
Clevite Bearings* $75 New
ARP studs* $440 New
Ferrea Valves* $700 New
Comp Cams
Beehive springs* $250 New
Retainers* $70 New
S2 euro cams* reground by Piper $400
DLC coated lifters by Anatech $500
Bore torque plates to be made $300
Boring $600
Decking and other machine work $500
Offset grind and modify crank $850
Modify intake system
(change runner diameters and lengths) $400
Exhaust headers and system, $1500
Headwork $2000
Management system Motec $3000
Customize sump and other parts
for dry sump $1000
Gasket kit and waterpump $850
$hit I'm now scared to add it up.
Plus I'm sure there are little things that I'm sure I have missed. Anyway I think that is probably reasonable if the outcome is a good one. Any thoughts?

Cheers Greg.

Chris

Nice job Greg, you are a brave man (at least IMO) for trying this out and it is a nice change to see details .... wish I had something to contribute technically but this is out of my league.

As for costs ... yep, sure have a way of creeping up on you !

Chris

toofast928

Keep it up Greg. 16v has hidden potential! Spinning the engine to 7500 RPM..WOW...............

drnick

greg, make sure and post pics/details of the sump modifications to run the drysump!

BC

Beehive springs? I know of them, but which size/part number did you use? What seat pressure Open and closed?

Normy - this isn't offtopic - cut the attitude. There is no comparison between the engines. Do you even know what motec does or is?

Great stuff Greg. Keep us posted.

Brent 89-GT

I will be very impressed if it pulls 500+ hp. My only comparison is the big Buick engine I had built last year. That thing is 464 cubes and the heads flow 276 @.500 lift on the intake. The cam is 238 dur .540 lift, 10.5:1 comp and made 525 hp on the dyno. Of course it only spins 6000 rpm and breathes through a carb but 500 hp from a NA 5.7L anything is stout. Very intersting project, Good Luck.

That 302 you mentioned would probably be too much for a street engine. I suspect it would have low vacuum and run rough as a cob. That is a wicked cam for that little engine.