Got Darrell's cylinder heads assembled today. SI valves, Comp Cams beehive springs, with Comp retainers, locks, seals, and spring seats. Spring pressures came in at 160 seat and 375 open, with a nominal 1.925" install height.

Also poured a couple of chambers and they came in at 80cc on the money with these valves and a set of AR3924 plugs.

http://i170.photobucket.com/albums/u...ps5ed449e3.jpg

Crankshaft is on the way, pistons are ordered, and the camshaft is ordered: Comp Cams billet steel hydraulic roller, 251/257 @ .050", .635"/.590" lift. 110 LSA.

Nice! Why the beehive springs?

SB

Brent, given valve weight and cam profile isn't 375 a bit light on the open side?

No sir....

That amount of spring pressure, combined with a light action spring, light retainer, etc., etc. should be beyond adequate for a 6000-6200 rpm engine. The valves are 11/32" stem, and although they are 2.250/1.760, they are not portly. I also don't use overly aggressive hydraulic roller lobes. These lobes are actually "Thumpr" lobes, but put together in a custom cam to get away from their Thumpr trademark characteristics. As a whole, the lobes are very quiet and are not overly aggressive.

SB, the reason for beehives was:

1. Darrell requested them.

2. He also requested that the peak hp rpm be above 6000 by a little bit. Typically we have issues with "normal" FE hydraulic roller scenarios and making power above 6000. With a combination of lighter valvetrain parts (lighter valves, very small & light retainers, etc.), and some lifter tricks, I think we can edge a little above 6000. The heads and the cam will be more than adequate for that rpm, but we just have to try and skirt around some FE hydraulics issues.

You don't really notice it in the car, but on the dyno, we normally start to hear the lifters lose control around the 6000 rpm mark.

Thanks for the detailed answer Brent. I myself prefer behives over dual/triple springs, when practical. My 'other' fun car uses them and it's a 427 too, with a 7100 factory red line.

Brent,

Thanks for sharing the tech info on the springs!

SB

I've been looking at the recently released "conical" springs. They give us the small size retainer and weight reduction, while giving me the advantages of a double spring too

Parts still trickling in....

Blue Thunder intake, Comp Cams camshaft...

http://i170.photobucket.com/albums/u...psf279edab.jpg

http://i170.photobucket.com/albums/u...ps6cdcd097.jpg

RPM crankshaft is here as well.

Brent this one make any progress?

A progress report from both Brent and you (as to when your SPF will arrive) will liven things up a bit.

I will be giving a progress update soon. The progress is slower than I would like.

I've about got Darrell's engine finished up. Waiting on the valve covers to show up and it's done.

Things go slowly sometimes. It's not how we like for it to go, and trust me, I want to move product in a timely basis. However, if anyone knew the amount of time and concentration that goes into doing one of these, plus the collaboration of manpower, there would be a little time "fluffing".

On this particular build, I was measuring the crank and saw up to .0006" out-of-round on some journals, and some intolerable amount of taper on some others. This means that the crank has to go to the crank grinder. This means that you have to get the crank into their queue...which means waiting.

Had the block machined then went to measure piston/cylinder clearance and saw that I didn't have enough, because the pistons were a tad (1/2 thou) oversized. Wasn't anyone's fault, just a stacking of tolerances and needed to be corrected.

I've got some pictures to upload of this one going together. I'll try to post them a bit later. I've already emailed them to Darrell for a progress report, but can post them here publicly too.

It's also nice to try to time the engine delivery with the car completion. It's really not good for engines to sit around doing nothing and I've had customers who have jumped up and down to get their engines *immediately* then 3 years later their projects are not complete. No lie.

Racetec forged pistons, hung on Scat H-beam rods.

http://i170.photobucket.com/albums/u...psnek6beia.jpg

Finished rotating assembly.

http://i170.photobucket.com/albums/u...psqmgczjd6.jpg

http://i170.photobucket.com/albums/u...pscqufvjrq.jpg

http://i170.photobucket.com/albums/u...psjgw01u9m.jpg

If you would quit chasing soap bubbles around the backyard, you might actually get some work done!:D

True dat.....but there will only be so many opportunities to chase bubbles. :o (And we did chase a few this evening, thanks Jim. :))

Enjoy it while you can. They grow up way too fast and become teenagers! :CRY:

How about 618 hp and 671 lbft of torque?

Impressive
 

671 Torque, plan on pulling stumps with this one.

What RPM?

Nice engine, Brent!
Love how connected you are to the forum.
:3DSMILE:

Dyno sheet shows 6000 as the hp peak, but since it's a Stuska dyno with a manual control, sometimes it shows a little higher hp and peak since Nick was starting to back off the water. I would say the hp peak was at 5700.

Torque peak was at 4000.

Had time to get home, get the engine unloaded and unwind a little bit. Was very surprised at the torque, horsepower was about what I expected with a shorter hydraulic roller and a dual plane intake.

I'll post final pics later so everybody can have a look-see. The intended valve covers were shipped to another customer, so I had to "borrow" another set of Blue Thunders from another customer. Didn't even have breathers, just two AN fittings for a vacuum pump hook-up...LOL

Should push a Cobra along pretty well. :)

Video....[ame]https://www.youtube.com/watch?v=Ivm8nA_NK7I[/ame]