Stroker Heads

[kountzecobra]

I am building a 545" stroker for one of my cars. Has anyone here used Ford's new SCJ aluminum heads? Is this a good choice for a street engine? What about Edelbrock's cobra jet port size heads?

[Tom Wells]

Hi David,

If I was building a bigger engine (someday?) I'd use those heads

Here's Kaase's take on the development:

Kaase's CJ 460 head development writeup

Note that the cam profile has considerable influence, and watch out for piston to valve clearance!

As an afterthought, killing a bit of low end might be a good thing

Regards,

Tom

PS: Dunno anything about the Edelbrocks, but if you're looking around, the 385 bunch seems to like the TFS heads, too. Here's another URL:

385 Forum head flow comparison

[kountzecobra]

Thanks Tom. I read the same info you have and visit the 385 forum and thought the SCJ heads looked pretty good too. I will contact Jon Kaase and see what he thinks about using these heads with the Blue Thunder 2x4 intake manifold after the ports have been opened up to match. Any suggestions are appreciated.

[djseed]

I am using the new Kaase SCJ heads. They are designed to fit the 2.25" intake valves without problems. They flow just like they say as I had mine tested. They are the OEM replacement part so everything fits like the original iron heads. I used the KB hypereutectic pistons and did not have to cut any new valve reliefs. I have 9.95 to 1 compression with the Eagle stroker kit. The cam is a Crane hydraulic roller with .59" I and .614" E lift. I also liked the idea that with the new intake position you can run less advance and keep the same HP. I tried this and reduced the advance from 35 to 30 degrees and the HP and TQ went up on the dyno. Less chance for detonation with less advance. I bought my heads and valve train girdle direct from Jon and he was very helpful. I have pictures in my gallery of the heads being tested.

[wboss429]

i like blue thunder over scj, ive done 4 engines 500'' w/blue th heads

2 w/cj heads, 1 w/elder b heads, same comp,tried same(5 diff intakes on the elderbrock heads) intake,in fact we have a set of used cj's for sale,there being replaced w/blues,now heres the problem, w/blues u must recut pistion w/anyknid of real lift. a real problem if ur pistions r in the car........................



old cj's u dont have to do this, and now with the new scj ive read u do, i have not used his new scj head because
valve angle has changed, ask john about that ,before u order pistions,the scj head is a good head,it does cost more for the blue t.

i guess it really dependes on what ur looking for,

not trying to confuse,trying to help


ps i like the taller ehx port of the blue th,and the raised intake

[xlr8or]

David,
If you have more than about 580 lift at the valve I believe you have to cut the pistons for clearance because of the valve angle change. The valve angle may make some other valve train changes necessary as well for the push rods and rockers. The good news is that new heads are supposed to get you up to 90 HP over the old design.

[cobrashoch]

wboss429 - Chevy port or Ford port Blue Thunders? Which chambers?

My experience has the Chevy port B.T. head (mildly ported) as the best I've seen, for running a engine from 2000 to 4000 R's. Without screwing up the lower power band that is, like the "A's" and even the "C's" . And by a large margin I might add. That's not something measured on a flow bench either.
My old buddy Russ at Indy Cylinder Head tells me a ported RPM Edelbrock looks to be very close to the "C's" overall. Can't argue with the price of the Edelbrocks though, when you really think about it. The jury is still out on the Kaase heads he told me.
Personally, I'm always skeptical when someone tells me he can give me 90 more horsepower with the latest and greatest hot rod part. My question is - "at what price?" Nothing comes free, there's allways trades to be made. It is possible I suppose.

cobrashock

[djseed]

xlr8or

I had a competition build done on the engine. It was built the first time to check clearances and then taken apart and work done. It was then assembled again for the 2nd and final time. I did leave .005 on the deck and I had custom push rods done. The builder was surprised that he did not have to fly cut the pistons. I used the Keith Black pistons with a -30 cc dish.

wboss429

I understand that BT does make a good head. The issue is with the non-stock position of the exhaust ports. With the SPF BB 385 headers and side pipes, this forces the side pipes out of position slightly.

[cobrashoch]

As quoted by djseed;
I understand that BT does make a good head. The issue is with the non-stock position of the exhaust ports. With the SPF BB 385 headers and side pipes, this forces the side pipes out of position slightly. [quote]

Amen brother - Try finding 2-3/8 inch Chevy shorties that will fit a Cobra sometime.

cobrashock

[wboss429]

chevy ports r good for about 5 cfm more,out of the box,wopted do,
go w/the ford............


yes port is about .500 inch taller ,this nessataites the use of longer head bolts on ehx side,which b t also sells



wboss

[SUPERGONZO]

Has anyone stroked a BOSS 429 block, using the BOSS 429 heads?