690's & aluminum

[petepedlar]

So why do 690's, rebuilt with new valves still bring $2500 - $3000 on Ebay when you could buy new aluminum ones complete for $2999 ????????:dunno

Dave

[Brian Thompson]

Originality... Not for me though. i will be getting some of Bob's heads when Ronnie gets the short block done! :D :D

[models916]

Lots of guys out there not knowing what they are doing or what things are worth. I sell a lot of used junk for more than it would cost new on the bay.

[dq409]

So why do 690's, rebuilt with new valves still bring $2500 - $3000 on Ebay when you could buy new aluminum ones complete for $2999 ????????:dunno

Dave

Come on guys,,, These 690 heads are really hard to find,,, you know that !!!:takethat

If you are restoring a engine or car you NEED the stock numbered matching iron heads which will always go for a premium price being so scarce.
.

[impalamike.com]

Whats the latest on the block. Whats a link to the assembled heads?

[Dond409]

Here's a link for a set that Jack Gibbs has for sale on EBAY.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=003&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=130164631513&rd=1

[CDNpontiac409guy]

OK.... photos. You guys need photos of these aluminum heads... INCLUDING some that compare them to standard 690 / 583 castings.
I'll post a whole series of pictures. These are not the high resolution versions, but you'll still be able to tell what's going on.
Here there are:

[CDNpontiac409guy]

The ports in the new heads, as you can see, are MUCH smaller than factory... at the opening. Where the "as cast" advantage is, is in the valve pockets. The new head is a good 1/2" deeper in that area... COMPLETELY unshrouded. They require 30-60 minutes per port, of careful work. After this, they will out perform any non-welded / reworked 690/583 iron head... but it WILL take some doing.

[CDNpontiac409guy]

and a few more:

[jim_ss409]

Great pictures Aubrey.:deal

[chevytaylor]

Hi Aubrey

Excellent photos. Thankyou for the time and effort involved. :clap

Have you done any flow testing as yet?

chevytaylor

[buildit]

Appreciate the photos, Aubrey, they answer a few questions.:clap

[CDNpontiac409guy]

Yes, I was hoping they would help give a "visual":deal

Taylor... I think jim_ss409 can probably answer questions about flow. I have been told that measured at .700" valve lift, in fully ported condition, they will flow approximately 350 / 235 CFM.

[jim_ss409]

Yes, I was hoping they would help give a "visual":deal

Taylor... I think jim_ss409 can probably answer questions about flow. I have been told that measured at .700" valve lift, in fully ported condition, they will flow approximately 350 / 235 CFM.


My "race ported" heads are the ones that Bob got the numbers from on his site...
http://www.409raceparts.com/
Here are the numbers...

IN / EX
.100 - 101 / 73
.200 - 178 / 124
.300 - 251 / 171
.400 - 303 / 201
.500 - 330 / 223
.600 - 341 / 236
.700 - 353 / 245
.800 - 360 / 252

They were done by Mike Stark, a cylinder head guy with a really good reputation. The valves sizes were increased to 2.25 int. and 1.75 ext. Even after porting the port entry is still smaller than the stock 690's. The throttle response is really good so I'm sure they'd work great on a street motor. My engine has only 9.75 to 1 compression and a relatively small cam for a race car, so I'm not really taking full advantage of the ported heads, but I wanted to get them ported so they'd be ready for when I step up the rpm and horsepower. I think getting the heads ported or at least cleaned up by someone like Aubrey is always good, if you can squeeze it into the budget.

[impalamike.com]

Great looking heads!! Whats up with the blocks?

[dq409]

My "race ported" heads are the ones that Bob got the numbers from on his site...
http://www.409raceparts.com/
Here are the numbers...

IN / EX
.100 - 101 / 73
.200 - 178 / 124
.300 - 251 / 171
.400 - 303 / 201
.500 - 330 / 223
.600 - 341 / 236
.700 - 353 / 245
.800 - 360 / 252

I wanted to get them ported so they'd be ready for when I step up the rpm and horsepower. I think getting the heads ported or at least cleaned up by someone like Aubrey is always good, if you can squeeze it into the budget.


$4000 for a set of heads that need porting ????? :dunno :dunno

[Bungy]

The way I read it, is that the $4000 figure is fully assembled with the race porting. The bare castings are $2500.

[jim_ss409]

The way I read it, is that the $4000 figure is fully assembled with the race porting. The bare castings are $2500.

Yeah, that's right. In fact I think the bare castings are going for a little less right now. A race ported set of heads with larger valves and high quality valve springs and retainers will get you up into the $4,000 range. The heads flow well right out of the box, but even just a bit of cleanup and bowl work would probably bump up the flow quite a bit.
By the way,,, The guy that ported my heads said that with more work, there was more flow to be had, but you reach a point of diminishing gains for the amount spent. He also said that there was a LOT more flow potential if the heads were done into a raised port, Z11 style, version. The heads are cast so that the ports can be raised without much trouble. And even the two center exhaust ports are cast in a way that allows them to be raised. I think that by next spring we will start seeing some of these heads find there way on to engines that are designed to take advantage of their full potential.

[CDNpontiac409guy]

Thought I better clear up any misunderstandings here...
The heads I have here, which I photographed, are intended to go to builders.
Bob just advised me, that the heads he sends out directly to the end user, are already pre-prepped in that port entrance, so there's very little to do before running them on a typical street engine.

As Jim pointed out above.... these heads are versatile. They have deliberately been cast in such a way, that they can be very highly/finely "tuned"... and in an ultimate prepared state, are quite beyond anything a 690/583 head is capable of.

[petepedlar]

The ones on Ebay are $2250 for the heads with guides, guide plates & seats. With SS valves, springs, etc ready to run are $2999.99 . The item number is130164631513

[1958 delivery]

My "race ported" heads are the ones that Bob got the numbers from on his site...
http://www.409raceparts.com/
Here are the numbers...

IN / EX
.100 - 101 / 73
.200 - 178 / 124
.300 - 251 / 171
.400 - 303 / 201
.500 - 330 / 223
.600 - 341 / 236
.700 - 353 / 245
.800 - 360 / 252

They were done by Mike Stark, a cylinder head guy with a really good reputation. The valves sizes were increased to 2.25 int. and 1.75 ext. Even after porting the port entry is still smaller than the stock 690's. The throttle response is really good so I'm sure they'd work great on a street motor. My engine has only 9.75 to 1 compression and a relatively small cam for a race car, so I'm not really taking full advantage of the ported heads, but I wanted to get them ported so they'd be ready for when I step up the rpm and horsepower. I think getting the heads ported or at least cleaned up by someone like Aubrey is always good, if you can squeeze it into the budget.


1.75 exhaust...why so small?

[jim_ss409]

1.75 exhaust...why so small?
If you went much bigger on the exhaust you'd have to go smaller on the intake valve because they're pretty close together at 2.25 int. and 1.75 ext.
Also, because of the way the exhaust valve gets closer to the cylinder wall when it opens, you'd have to reduce lift if you went much bigger.
I notice that the experts seem to place more importance on intake flow than exhaust flow. They say extra duration can usually balance things out if the exhaust flow is weak. These heads have a good intake to exhaust flow ratio so it's not really a problem.

[hogmotors]

Aubry,
HOW OLD are those studs(in the Al/CI comparison)??I haven't seen any of those since 67 when I got my 1st engine out of a crashed GN car!!
Cool!
G

[CDNpontiac409guy]

No doubt, eh Gordon:cool:
I got the heads in that condition, in 2001, from a 63 QB engine that was bored .125", with a set of Jahns 12:1 cast pistons.
The guy needed the 62 690's that I had.