Edelbrock heads

[go-fish]

I have found what sounds like a hell of a deal on a set of Bischof ported 340 Edelbrock heads. They were on a car at Hotrod's Drag Week running in the 10's. He says he used them on a 360 before building his 417" stroker. I have a 360 that I could use these on. These heads are about 6 years old but have few miles on them, also, all the moving parts are brand new with 2.08/1.60 valves and crane 1.6 rollers. They were on a 550+ hp engine.
Has anyone ever heard of any structural integrity issues with these ealier Eddy heads? I thought I had at one point but not for certain.
I had my eyes on Indy heads but the price is right on these. They are open chambers, but not really. They have a .060cc relief cut in them for the 340 pop-up style pistons and been shaved .035, but otherwise they look like closed chamber in design. These are going to be under 65cc, closed chamber #'s. That is how small that .060cc relief is.
However, my .030 over 360 cylinders are going to be somewhat larger than the relief cut, creating kind of a step. The link shows what I am talking about. They are the Performer RPM Chrysler 340 heads, #60179. http://www.edelbrock.com/automotive/headchrysler.html What do yo guys think?

[DartGT66]

Are you sure about your bores being larger? A 360 with a .030" overbore still has .010" smaller bore than a stock 340, so that way they should work. I would be more concerned about the head to piston clearance. What is your piston height at TDC? flat tops? what about valve reliefs and so on? What kind of gas and cam will be used?

[go-fish]

I have some quench dome Diamonds. I don't know the piston height at TDC. They are stroker pitons that have small valve relief cuts. The compression is 8.5:1 because it is a forced induction set up, using a D1-SC. I was initially concerned with them being an open chamber head, but they are nowhere near as open as the stock head which is something like 73cc? I need a cc in the 65 and down rage to minimize detonation. I am currently not in the States and can't really go back and check the pistons out but I bought them from Hughes who had to have Diamond make them, they were made with the intent of using the Indy 360-2 head or the Ed Performer RPM head. The heads in question are the RPM 340 head. The chambers are machined .060" for clearance with early, 68-73, high-compression 340 engines. These heads have the same features as the 318/360/340 heads but with a chamber especially for this application. These heads have also been shaved .035 , further reducing the size of it's .060 pocket.
I should have remembered about the bore sizes also, I am trying to learn this stuff. I found that out when I was questioning why a smaller displacement 340 would stroke to a more cubes using a 4.00" crank than a larger displacement engine,360, using a 4.00" crank. It's all in the bore size, so wouldn't the .060 pocket that is cut into these heads go over the .030 over 360 bores by .010", and would this create a problem? Again the link provided shows the .060 pocket that essentially makes thes "open" chambers.

[DartGT66]

I have never been to states, not even near.
You should aim at about .040" gap between the "machined side" of the chamber and the quench dome of the piston with the gasket. Typically the gaskets used are around .040" thick, so you should have the quench domes at about zero deck for proper clearance. So, it's possible, that you may have to mill some more from the heads, or use a little hinner head gaskets. I think Cometic has under .030" thick gaskets, at zero deck that would still leave you at .055", which is slightly on the high side.

[go-fish]

I'm gonna pck them up I guess.

[George G. Leverette]

Cutting on new heads is really questionable, were both sides cut so the intake will fit properly? What is the cost of these heads vs a new set from Hughes or Indy? Why were the new parts added? Why is the person getting rid of the heads? It just appears these heads are not for your specific application.

[go-fish]

The Hughes Ed heads with the upsize to 2.08 intake valve is quite a bit more. The heads were shaved for compression and the intake cut to match so the intake fits nicely. The Hughes Indy heads, heads/intake package, is about a thusand more.
From what I have figured these heads are the same as Eddy's other small Mopar head, just with a .060 pocket for the OE high compression 340. It will lower my compression a little but it should be negligable.
Man, I don't know. I'm flip floppin' on this deal. I guess if I'm wrestling with it in my head this much I should walk away from the deal. I know that it isn't the best possible head for my engine. I am going to call thesuperchargerstore.com guys on this to see if they have had customers that ran the Eddy 340 heads with this .060 pocket since they are the ones that highly recommended getting closed chambers. I was just thinking that these heads are so close to a closed chamber design that the differance was negligable, but I am not experienced so my assumption don't mean anything.