Neil B

Ok guys, my plans have changed. I bought a set of Brodix Race Rite 294cc Rectangular Port heads a couple of weeks ago with plans to put a new top end package on my 468. Yesterday, I found a used 4.500 bore Bow Tie block (older 1107 casting), GM 7416 steel crank, and Eagle H-beam rods swinging a set of vintage Manley/TRW forged pistons. The bores look outstanding and the crank is still STD/STD on the mains and rod journals. The whole lot is heading to the machine shop tomorrow to be measured and checked over. If the crank checks out, I will definitely leave it a 4" stroke because the heads are too small for a 540. So how would you guys build it?

dmaxx3500

you should just buy my 588'' engine[just dyno time]

tt 383

Send the heads back?

Neil B

What are your thoughts here? The heads have not shipped yet, but they were a custom order with CNC chambers, custom springs, and exhaust seals. I could probably change the order if I called them tomorrow. I think the 294cc head will still work nice for a low 6,000 rpm 509ci hydraulic roller combo. Standard height exhaust ports are a must-have with this project, so I think that limits me to the 270/294 Race Rites from Brodix. I think the 312cc BB2's have a .600" raised exhaust port.

427Hotrod

I've got the .600" raised Brodix on my car. I think the headers actually fit a little better.

Do they offer The Race Rites with CNC porting? They will be Ok for a hyd roller 509. You're not going to be spinning much past 6500 rpm.

How much power are you looking for?

I'm a Brodix fan....there's other good ones out there but Brodix makes nice stuff.

JIM

gkull

People are so concerned about 600 raised exhaust ports you have to understand that the because of a V8 it's outboard not just straight up I've used race Port heads for 30 years

Neil B

They offer a full CNC 298cc BB-3 XTRA O (24 degree), but it seems like a bit overkill for my application, especially with my hood limiting me to a Performer RPM intake. I'll be happy with 600-620hp and 6,500rpm.

Neil B

Yeah, it's a tough call on whether they will work or not. My side pipe headers are already really really close to the steering box and frame rail.

69ttop502

My AFR 315's caused my Hooker sidemounts all kinds of fit problems with just the .375 raised port. Seems hit or miss. I got tired of sidemounts so ended up having a header/exhaust system built. I built my 502 at 10 to 1 compression, AFR 315's, stock forged crank but had it internally balanced, fully ported Holley Strip Dominator intake which fits perfect with L88 hood and airbox. I used SRP pistons and the Eagle H beam rods with L19 bolts. I have a Holley 1000 hp carb. First cam was a solid flat tappet and made 614 hp at 6100 rpm. Just put a mild, but bigger solid roller in it and made 653 at 6500 rpm. Haven't driven it yet with this cam but it's gonna be fun. Sounds like your motor will be similar to mine. Just don't go too small on the cam.

Bill

Neil B

Hey Bill, sounds like a nice combo you have there. I'm also looking at the SRP piston with the -17cc dome. That would give me 10.5:1 - 10.6:1 compression with an off-the-shelf piston. I'm starting to look at camshafts with intake duration in the 240's@.050 range (hydraulic roller). A solid roller would be more fun though. Maybe I'll sell my lifters and go that route.

427Hotrod

The best flowing heads you can get is always a good investment. They work better at the start and allow growth later on down the line. Of course there's a limit to budget too!

If building to a certain HP goal then you just get what you need. I've got a set of 3Xtra oval CNC 365's on my 555". Big...but they work well.

Where do you want RPM range/Peak HP? The head choice will determine cam needs along with RPM range and HP goals.


GOOD hyd rollers are doing amazing things these days. Seems to be the lifters as much as anything. The best ones are expensive but they work well. Think Morel's. Cranes work well also.

JIM

427Hotrod

Nice package!!


JIM

Neil B

I called Brodix this morning and they still like the RR 294cc head for a 509 with 10.5:1 compression and a 6,500 rpm redline in a 3,200 lb. car.

Neil B

Hey Jim, yes I want the best heads that do not require custom side pipe headers. I want the motor to peak at 5,800-6,000 rpm with shift points around 6,500. I have a brand new set of Morel 4603's sitting on the shelf. From internet research, it seems the RR heads have a 2.72 CSA at the pushrod pinch which puts the choke rpm around 5,800-5,900 rpm on a 4" stroke 509. The throat CSA is around 3.1. If these heads flow anywhere near the 340 cfm advertised on my 4.500 bore, they will make the power I'm after.

roscobbc

I'm running with 489 cu ins and non cnc'd Brodix Race Rite 270 Oval Port heads. I've given-up some power by using a relatively mild flat tappet hydraulic cam. 10.5 c/r. With Performer air gap and DP Holley it dyno'ed at 570 bhp @ 5850 rpm. With 606 ft/lbs tq @ 3850 rpm there is little need to go past 6000 rpm. I would guess that use of rect ports would gain you another 1000 or so rpm at the possible cost of some lower end flexibility?

bmans vette

Wow Bill....that engine sounds sweet.
Guess I'll have to go to a SBC 427 instead of the 383 to keep up with you.

See ya soon buddy!

vetski179

Recently completed a 509 in my Nova. Originally bought a 502 short block. Planned to go with that with the original zz502 pistons. Bought Edelbrock Performer RPM heads bare, and went with 2.25/1.88 valves. Ported/polished/port-matched to manifold. (BTW, I understand Edelbrock cast the zz502 heads for Chevy, and put the bow tie emblem on them rather than their own. This from a tech @ Edelbrock) Ultra Pro Magnum Rocker Arms.
Due to and assembly error on my part, had to bore .030 and go with flat tops. The heads have small chambers (110cc), so the compression was OK. However, if I knew ahead of time I'd be going with new pistons, I'd have gone with open chamber heads with the appropriate pistons to get the compression up a bit, as well as there's a much larger selection of heads in the open chamber design.
Used the stock zz502 crank and rods (had it balanced).
Cam is a 2262 hyd roller Edelbrock, which sounds LOVELY through the 3" Flowmaster exhaust!
Manifold is a 2904 Edelbrock with a 750 DP.
(Will be upsizing to a bigger carb soon, as this carb will be on my c3 projects 454sbc)
Super happy with the combo! It's like a 427 on steriods.

GOSFAST

Budget/cost aside, I see just a couple problems with your parts choices, first, that early Bow-Tie block probably lacks the inner head bolt holes, not too big of a deal but they are nice to have, second, you will most likely not be able to "internally-balance" that shaft, and lastly, those pistons are likely to be some heavy pieces, most early TRW's were in that category.

Also, would not consider any "oval" port heads on a 4.500" bore platform!

Just delivered 2 similar builds, both 509's, first one was a 100% stock-appearing piece but with the Bow-Tie block, all other external pieces OEM for a '66 Vette, square-port iron heads. The other for a '66 Chevelle.

The Chevelle was a basic bolt-together build, 9.5:1, solid roller, RHS heads. Made 680 HP @ 6400 with 620 TQ @ 5200.

Thanks, Gary in N.Y.

P.S. That block you have (if it doesn't have the inner head bolt bosses) was in very high demand at one point. Before using it I would put out "feelers" for anyone interested in it. A few years back we traded a couple brand new Bow-Tie blocks (still in the crate) "heads-up" for two of those early castings. I don't need any today but it may be worth looking into still??

Neil B

The block, crank and rods were delivered to the machine shop today. The parts checked out and could have been assembled 'as-is' with just a slight hone on the bores and mains. With the age, weight and design of the pistons, I made the decision to put new slugs in it. We went with a 4.530" SRP -17cc dome piston. I'm going to use the crank and rods, but I'm upgrading the rod bolts. This should put final displacement at 515ci with 10.6:1 compression. The 294cc heads are in the shipping department at Brodix. They might work out perfect for my planned 6,000 rpm peak but I may elect to do some port work on them (gotta think that over).

Neil B

That's good info! May I ask what cam you are running? Apparently the 294's are really the same as the 270's except the intake port is opened up and blended back into the runner. I'm not sure how much cross-section is actually gained.