New SBC heads
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New SBC heads
So I got my new Chi-na heads today and after a quick look I thought to myself, these look just like my Dart 200's except for the chambers volume. The bowls, the exhaust ports and the valve seats all looked identical until I got to the intake port opening. Now the port is tall using a 1206 gasket, they are not raised runner so no problem with intake manifolds but the pinch is super narrow and looked even smaller than factory Vortec heads. I am going to use my Dart cast heads as sort of a template to open the pinch up so these will flow more like the Darts I have now. I know I should not use stuff like this but I really wanted to see why guys can't make any power with these heads so after seeing the pinch that may be the very reason and the fact that the intake could use at least a 2.05 valve these look pretty good. The decks are super thick and could be a 49cc head they were angle milled and flat milled after that, but on my one 406, these might work pretty good for a el-cheapo deal.
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Re: New SBC heads
I will be interested in the final size of the pinch in relation to valve/ throat size and average CSA .I like the idea of angle milling.
steve c
"Pretty don't make power"
"Pretty don't make power"
Re: New SBC heads
Thanks Steve, I think the decks on these heads are like .750 thick. I will flow the cast iron Darts and these at the same time so that should be a pretty good test as they are both 200cc runners, well the copies will be after I get done with them.steve cowan wrote: ↑Tue Aug 02, 2022 9:56 pm I will be interested in the final size of the pinch in relation to valve/ throat size and average CSA .I like the idea of angle milling.
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Re: New SBC heads
On your 406 they should work really good super victor or holley strip dominator??
steve c
"Pretty don't make power"
"Pretty don't make power"
Re: New SBC heads
If your heads have a number 12DO115 above the center exhaust ports, check the top row of head bolt holes for alignment. I just fixed a set that were off left to right so far, the bolts would not start to thread in without forcing them.
This set had numerous other problems, but that was more related to the customer taking the seller's word for the description of the heads.
Hope yours are not the same. Greg
This set had numerous other problems, but that was more related to the customer taking the seller's word for the description of the heads.
Hope yours are not the same. Greg
Re: New SBC heads
Which "brand" did you end up with?
Did a few of the AFR versions and they seemed like a pretty nice casting.
This set build for a "street" solid roller combination in a tri-five Chevy gasser deal.
Did a few of the AFR versions and they seemed like a pretty nice casting.
This set build for a "street" solid roller combination in a tri-five Chevy gasser deal.
"Quality" is like buying oats. You can pay a fair price for it and get some good quality oats,
or you can get it a hell of a lot cheaper, when it's already been through the horse.
Nil Satis Nisi Optimum
Ed Curtis - www.FlowTechInduction.com
or you can get it a hell of a lot cheaper, when it's already been through the horse.
Nil Satis Nisi Optimum
Ed Curtis - www.FlowTechInduction.com
Re: New SBC heads
I am going to use my Ported 2925 S/V on these heads since it's ported to the 1206 gaskets and the new heads are about that height in the opening. I have to tell you the pinch when I checked them against my Dart 200s were a 1/4" smaller. Anyone see a problem with that? otherwise everything is almost identical to the Dart heads.steve cowan wrote: ↑Thu Aug 04, 2022 2:00 am On your 406 they should work really good super victor or holley strip dominator??
The new aluminum heads bare came in at 20 lbs.
The cast iron Darts came in at 50 lbs.
So 60 lbs. of the front of the car and another 30 lbs. off with the new aluminum radiator deal, close to 100 lbs.
Re: New SBC heads
Mine were off of Amazon The Dynasty Store. They are pretty much all the same except the AFR's have a better finish work done to them.
Re: New SBC heads
You can DIY carve the pinch as big as you need.
These heads are intended to be ported by the end user.
These heads are intended to be ported by the end user.
Re: New SBC heads
Eric Weingertener has some vids on chinese heads on youtube, may be worth checking out.
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Re: New SBC heads
I calculated using a mach index of 690 ft/ sec for your cubes at 7000 rpm a minimum csa of 2.35in2 factors in radius,1980RS wrote: ↑Thu Aug 04, 2022 8:38 pmI am going to use my Ported 2925 S/V on these heads since it's ported to the 1206 gaskets and the new heads are about that height in the opening. I have to tell you the pinch when I checked them against my Dart 200s were a 1/4" smaller. Anyone see a problem with that? otherwise everything is almost identical to the Dart heads.steve cowan wrote: ↑Thu Aug 04, 2022 2:00 am On your 406 they should work really good super victor or holley strip dominator??
The new aluminum heads bare came in at 20 lbs.
The cast iron Darts came in at 50 lbs.
So 60 lbs. of the front of the car and another 30 lbs. off with the new aluminum radiator deal, close to 100 lbs.
Not sure if you can get area without blowing the pinch out.
Otherwise all you can do is make it as big as possible.
steve c
"Pretty don't make power"
"Pretty don't make power"
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Re: New SBC heads
Steve, what minimum CSA do you calculate for 377 at 7K rpm? Are you using a version of pipemax? I have a pair of these I'll be playing with soon hopefully, the first thing I noticed when I took them out of the packaging was how tight it was at the pushrod pinch. Planning on 2.08/1.60 valve.steve cowan wrote: ↑Thu Aug 04, 2022 11:02 pmI calculated using a mach index of 690 ft/ sec for your cubes at 7000 rpm a minimum csa of 2.35in2 factors in radius,1980RS wrote: ↑Thu Aug 04, 2022 8:38 pmI am going to use my Ported 2925 S/V on these heads since it's ported to the 1206 gaskets and the new heads are about that height in the opening. I have to tell you the pinch when I checked them against my Dart 200s were a 1/4" smaller. Anyone see a problem with that? otherwise everything is almost identical to the Dart heads.steve cowan wrote: ↑Thu Aug 04, 2022 2:00 am On your 406 they should work really good super victor or holley strip dominator??
The new aluminum heads bare came in at 20 lbs.
The cast iron Darts came in at 50 lbs.
So 60 lbs. of the front of the car and another 30 lbs. off with the new aluminum radiator deal, close to 100 lbs.
Not sure if you can get area without blowing the pinch out.
Otherwise all you can do is make it as big as possible.
Pro question poster.
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Re: New SBC heads
EDC those springs look small for a solid roller? what are they and how big is the cam?
Pro question poster.
Re: New SBC heads
The Dart copies were a little over 1/8" width smaller than the Dart 200's I have. Quite a difference.
Re: New SBC heads
With the as cast meat at the pinch you have the capacity to now create the size and SHAPE of the radius of the pinch, as you port these heads for power.
Keep us informed as you do the workup on these heads.