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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
Anyhow... There's that wedge that's visible on the intake and I'm wondering if I'd be making a really lame mistake to try to grind that flush with the bottom edge of the seat... As in, possibly hitting water.
Every time I've done a build, which is about once every 10 yrs, I do some of my own headwork, which doesn't amount to much other than some very basic blending, radiusing and smoothing.
And so far it's been successful... There's always been an improvement in power and I've never nicked a seat or hit water.
But this is the first time I've been concerned that I might mess something up.
I decided to get some budget aftermarket heads, this time, because the cost of the last valve job I had done cost just about as much as low priced aftermarket heads - assembled.
In the past all the valves I've worked with have been 1.94 / 1.5 - But these are 2.02s and that has created some issues of grinding thinner iron.
The valve job is actually a 6 angle seat job, with the bottom cut being cylindrical and concentric to the stem, of course, and it cuts into the side of the bowl about .040" - .070"
The actual amount of metal removed looks exaggerated by a bevel at the bottom.
These are Summit heads BTW - with 72cc chambers and 165cc intake ports.
Can anyone make any suggestions on how far I can go porting these without doing any damage?
Particularly in the area of the intake where the bottom cut goes into the side of the bowl.
Hope this makes sense
Thanks - I'm looking forward to finding out more
does this attach?
Last edited by ironhead88; 05-09-2019 at 12:28 AM.
I think you could smooth that off without any danger.. I don't think that would affect flow to any measurable degree if it was left as is .AFAIK,these Summit heads are Dart 'iron eagles cut for 2.02 valves instead of 1.94 on the Darts.The Dart heads are cast very nice and I don't think they will benefit from mild porting like stock GM heads do.
About being Dart castings; That's what I've heard. Although I don't see any casting ID that indicates that.
They get good reviews, mostly from guys who've used them to replace 76cc factory heads.
They're certainly a more advanced design than the smogger heads.
Guys said that they need to be disassembled and cleaned and that's true with mine. There was stuff in there where it shouldn't be.
The guides were a tiny bit looser than new valve jobs I've had done, but I'm not going to have guide inserts put in because the seats look so good that I don't want to have to re-cut them.
Overall, I have to give them high marks though
I'm looking forward to using them!
Last edited by ironhead88; 05-09-2019 at 12:33 AM.
my Dart iron eagles have a joined "cf""within a circle foundry logo cast into them and the valve job looks identical.I got my iron eagles to replace the tired old '624 76 cc smog heads on my car now.
my Dart iron eagles have a joined "cf""within a circle foundry logo cast into them and the valve job looks identical.I got my iron eagles to replace the tired old '624 76 cc smog heads on my car now.
I guess you like your heads.
Are yours the 72cc chambers with 165cc ports?
I like them,but can't say how they run yet-haven't got around to installing yet.Mine are the 67 cc chamber,165 ports version,bought mine unassembled to install Ferrea valves and all US made hardware.
There's a YouTube video of a guy who says that the way you did it is the best way... Buying bare castings
He also said that the chambers are cast the same size and they sink the valves to gain chamber volume.
It looks to me like the runner volume is a lot more than stock runners which are supposed to be 165. I think I'll measure mine just to find out
05-08-2019, 07:53 PM
