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Great build and hopefully you son has good friends and sense. That car will get him into trouble in a hurry, if he wants it🙂. I have set of filled #6 heads, 2"/1.625" valves and some port work. The exhaust ports look nice, I think the intake can use some work, won't know how much was done till I pull the valves. The guy I bought them from with 9.6 to 1 a .060" over 350 with a Comp 280H in a super heavy 74 Delta 88 ran 12.7's, can't be junk with those times and weight. Pics in the next couple of weeks.
Yes thanks, he will enjoy the ride. Still a bit away tho, was hoping this late summer he would of been using but build took too long. Now with number way over and beyond, need a built trans and rear end to take the additional power. Will send it to my freinds shop and will work over the winter on it. And have to run new exhaust cause ofvthe headers.
But with this all said and guys are calling #8's junk cause of smog heads. The tests came back, and that is a lie. If you dont port them then yes they are. But if you are porting a set of cast heads, way better off to go with #8"s. And there is a chart to show the flow numbers. Yes I put alot work into them but to me well worth it. Complete port and polish, risers filled 2 inch valves and seats, rocker studs. Yes you can buy aluminum heads and may do better, they still need to be played with. To me its not the same love for an Olds motor
I just did my first adventure in really trying to port heads. I've removed exhaust bumps, cleaned up flashing, unshrouded valves, gasket matched, etc before, but never more than that.
Took some fresh 60519's, unshrouded the valves to a 4.27" gasket, raised the exhaust bowl roof a ton (almost level with the port), tear dropped the intake guide boss (although current castings have a very small boss to begin with....), tried to lay back the short turn, blended anything real ugly. Quicky "polish" with 80 grit rolls on the walls. That's it. The bowls in these castings are pretty well blended to the seat already so not much to do there. Stock valves, no valve job yet, didn't cut down the exhaust guide.
My machinist has a Superflow 600 but hates running it. So he let me play around with it for an afternoon. My main concern was making sure I didn't ruin the head since, really, I have no idea what I'm doing.
Test configuration: 28" water, 4.155" bore, head clamped to machine with 4.27" cometic gasket. Putty around intake port, nothing on the exhaust port. No measurable leakage.
"60519 unshroud" is an out-of-the-box 60519 with just the chambers opened up to 4.27". "60519 JO" is the one I did all the porting to.
"60519 stock" is CutlassEFI's numbers, so of course can't guarantee direct comparison. Interesting the 0.100" numbers on mine are so much lower.
Given all that porting took somewhere around 4 hours, was it worth it? I guess so on the exhaust, but looks like the current ebrock intake is as good as it's going to get without serious work (moving pushrods, sleeving bolt holes, bigger valve, someone knowing what they're doing, etc). It was interesting on the bench - the unported exhaust port just sounded awful. Tons of turbulence. The ported one still sounded like crap, but much less crappy. The current ebrock casting also has a pretty funny ski jump ledge on the exhaust port exit.
At least I didn't ruin the head, and didn't poke any unwanted holes in it.
Now to figure out how to reliably install and size guides...........
Nice job Jason. Don’t worry about the @.100 numbers, piston isn’t really doing much at that point anyway.
Thanks, Mark. Wasn't sure if maybe the 0.1 numbers are indicating a difference in the test bench, difference in the head, or difference in the operator. There's a reason the Superflow template flow sheets have a spot to write down who operated the bench.
Regardless, at least my work showed gains and not losses.
He had a LS head sitting around that he flowed a couple of years ago. I used that as a benchmark and got the same numbers he got, so seems I'm running the bench the same way he was. Well, the same way whoever the dude was that he used to call in to run the bench.
Man. What a trip this thread is. Those heads that kinda kicked off this thread which 67cutlassfreak did have worked great for me. With my 72 cutlass running a best of 11.68 @ 111 mph. With the little 350 . In the coming months I plan on porting my own heads for a little SBO project I plan. Probably one of the best threads on this website.
Man. What a trip this thread is. Those heads that kinda kicked off this thread which 67cutlassfreak did have worked great for me. With my 72 cutlass running a best of 11.68 @ 111 mph. With the little 350 . In the coming months I plan on porting my own heads for a little SBO project I plan. Probably one of the best threads on this website.
Yeah this thread is awesome. Lots to read and lots to learn.
I enjoyed porting the heads for Kelvins build.
During the covid shut down I decided to finish the 455 build I started years ago. 69 455 with C heads.
Had a diesel repair shop weld the center exhaust divider and a friend milled the exhaust gasket surface flush.
Sweet talked a buddy at a foundry and filled the cross overs.
I then polished the chambers, removed the 'egr' bump, smoothed out the bowls and guides. Also cc'd the chambers with within .2 cc. 82 cc final Lots of time invested ! ! Practiced on a set of Ga heads and broke thru
Ended up with 9.5:1 compression. dual spring yields 130 seat 340 open. Used a 230/236 flat tappet with an 850 double pumper, ported Edelbrock torker and headers. Engine runs great !! incredible power . . everywhere in rpm range ! Although I tend to avoid it, motor revs to 6,000 easily
Here are some pictures before the machine shop cut a 3 angle valve job, installed new guides, cut the valve spring seats to obtain proper installed height, and lightly milled the heads.
heat riser filled with aluminum a356 center divider welded and milled port before valve job and new guides chamber before guide work and valve job
During the covid shut down I decided to finish the 455 build I started years ago. 69 455 with C heads.
Had a diesel repair shop weld the center exhaust divider and a friend milled the exhaust gasket surface flush.
Sweet talked a buddy at a foundry and filled the cross overs.
I then polished the chambers, removed the 'egr' bump, smoothed out the bowls and guides. Also cc'd the chambers with within .2 cc. 82 cc final Lots of time invested ! ! Practiced on a set of Ga heads and broke thru
Ended up with 9.5:1 compression. dual spring yields 130 seat 340 open. Used a 230/236 flat tappet with an 850 double pumper, ported Edelbrock torker and headers. Engine runs great !! incredible power . . everywhere in rpm range ! Although I tend to avoid it, motor revs to 6,000 easily
Here are some pictures before the machine shop cut a 3 angle valve job, installed new guides, cut the valve spring seats to obtain proper installed height, and lightly milled the heads.
heat riser filled with aluminum a356 center divider welded and milled port before valve job and new guides chamber before guide work and valve job
I'm working on a pair of 1972 7a heads, and have a question about the short side radius. The intake valve size has been increased to 2.07. If I open the throat appropriately for the new valve size, and lay back the short side to the radius of the throat, it looks like I'll have to remove approx. .080-.090 of material at the short side apex. Is there enough material at the apex to do that, or should I take less to be safe?
Location: Colorado Springs Colorado/Thousand Oaks Ca
Posts: 1,719
Originally Posted by maxi426
I'm working on a pair of 1972 7a heads, and have a question about the short side radius. The intake valve size has been increased to 2.07. If I open the throat appropriately for the new valve size, and lay back the short side to the radius of the throat, it looks like I'll have to remove approx. .080-.090 of material at the short side apex. Is there enough material at the apex to do that, or should I take less to be safe?
Get a junk 7A head and cut it apart, you could also sonic CK. When your porting listen to the port, you can hear when its getting thin as well.
October 14th, 2019, 12:07 PM
