P.P.W9's and the goal of more HP

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I do think there is a level where there is to large of a port no matter the flow rate. Where that is, is a great question that I’m sure is super dependent on the combo of the build and what it is designed for. There is no clear answer to this unless your working on your engine, which still, require testing to actually know.

Freiburger of Engine Masters tried to find this out on a stroker 408 Ford and a tiny 218@050 cam. He had 3 differently ported levels of the same head and the big head made the same lower as the smaller head while the mid size made more power everywhere. This is a clue in this game.

Another thing I have said in the past is when your getting a ported head, look at what’s out there. Compare compare compare everything you can about the heads. And then look at your cam lift. If you’d only lifting to.500, then compare the heads flow rates to .500 because everything else there after dose t help in wing power. It’s not being used.

And as Greg said, price! Also consider the rocker gear as part of the total package price.
 
I'm just thinking that if there is little cost difference between say a CNC job that go 350cfm and 400cfm is there any real downside of not porting the head to it's full potential.

So it doesn't depend on what's under the heads? It would be interesting to see 400cfm heads on a 318 and actually drive it I bet. I also bet it would leave one wanting. J.Rob
 
I do think there is a level where there is to large of a port no matter the flow rate. Where that is, is a great question that I’m sure is super dependent on the combo of the build and what it is designed for. There is no clear answer to this unless your working on your engine, which still, require testing to actually know.

Freiburger of Engine Masters tried to find this out on a stroker 408 Ford and a tiny 218@050 cam. He had 3 differently ported levels of the same head and the big head made the same lower as the smaller head while the mid size made more power everywhere. This is a clue in this game.

Another thing I have said in the past is when your getting a ported head, look at what’s out there. Compare compare compare everything you can about the heads. And then look at your cam lift. If you’d only lifting to.500, then compare the heads flow rates to .500 because everything else there after dose t help in wing power. It’s not being used.

And as Greg said, price! Also consider the rocker gear as part of the total package price.

Just as with almost everything in life cylinder heads still fall under the "Goldilocks Rule". J.Rob
 
Cleaned up the heads and made an interesting discovery. What is causing 5 of the intake seats to erode? Is it water ingress and cavitation like seen on diesel cylinder sleeves. If it is where is the water coming from? Porous casting? Or is it the condensation and the hygroscopic nature of the alcohol pulling moisture out of the atmosphere? Or do I have it all wrong. J.Rob

seaterosion.jpg
 
I see the chipped valve seats once in a while.
It’s always been a valvetrain control issue with the ones I’ve seen, and hard brittle seats......like powdered metal.
 
Are the seats stainless? Stainless can corrode like that if not passivated before assembly. Typically you see it under stainless dock cleats or dissimilar metals. What happens is the surface is still reactive but the assembly prevents oxygen from entering and creating the 'white layer' on the stainless. Other high alloy steels that are not stainless can behave similarly too.
Once the corrosion reaches an edge, it breaks-out like you see. Properly passivating the surface to create the 'stainless' white layer is important prior to assembly for alloys susceptible to these kinds of reactions.

Just a theory, could be wrong, but I've seen similar on other applications before.
 
Sounds like the old Boss 302...massive ports,poor results
 
What is that on the valve spring seat area? Is the bare aluminum flaking?
 
Cleaned up the heads and made an interesting discovery. What is causing 5 of the intake seats to erode? Is it water ingress and cavitation like seen on diesel cylinder sleeves. If it is where is the water coming from? Porous casting? Or is it the condensation and the hygroscopic nature of the alcohol pulling moisture out of the atmosphere? Or do I have it all wrong. J.Rob

View attachment 1715684280


Any other signs of water in the chamber?
 
In the W8/9 circles I have a pretty conservative combo. My heads are an older Brett Miller design and have gone over 400 on two different benches. We dynoed with 2 different 598 intakes and didn’t see much change (760ish hp). This was using an “in house” Quick Fuel 1050 at IMM. I don’t have the pockets or desire to reach for the stars so when the engine went into the car I used my mild ported 598 intake topped with a nice lil Braswell 4825 as it would fit below my cowl hood. We ran over 220 passes in the high 9.4 / 9.5 range with no noted spring loss using or LSM tester often. It was a very consistent car and certainly fun to wheel with a 7500 shift point.

Ok.... I wondered one winter what a 904 trans would do behind this combo. I had a mild build one from our iron head 360 bracket engine combo so I reached out to Lenny at Ultimate to work his magic on a converter. It was also at that time I got a 598 that had been modified for a 1050. With those changes we went to Tucson in the winter and ran a 5.96 in some really crappy DA and 26.68 actually baro. Two weeks later at sea level (Irwindale) we went 5.79, but then wheel stood unloaded the rears, and hurt the car.

fast forward to last September at Famoso in 1800 DA we ran a 9.16 @ 145 and on one pass saw a 5.76 at the 1/8th which was another new best. That pass is with the Brett Miller R420-2 intake which is huge! I was hoping it would soften the hit, but we’ve gone a couple 1.22 60 times.

cam is a Crane core 264-272 at .050 108LSA .750 lift at retainer. I’m running leftover craftsman truck Jesel 1.6 rockers.
 
I see the chipped valve seats once in a while.
It’s always been a valvetrain control issue with the ones I’ve seen, and hard brittle seats......like powdered metal.


Mind if I ask what is powdered metal ? Is it metal that starts out from a powder { Aluminum } ?
 
In the W8/9 circles I have a pretty conservative combo. My heads are an older Brett Miller design and have gone over 400 on two different benches. We dynoed with 2 different 598 intakes and didn’t see much change (760ish hp). This was using an “in house” Quick Fuel 1050 at IMM. I don’t have the pockets or desire to reach for the stars so when the engine went into the car I used my mild ported 598 intake topped with a nice lil Braswell 4825 as it would fit below my cowl hood. We ran over 220 passes in the high 9.4 / 9.5 range with no noted spring loss using or LSM tester often. It was a very consistent car and certainly fun to wheel with a 7500 shift point.

Ok.... I wondered one winter what a 904 trans would do behind this combo. I had a mild build one from our iron head 360 bracket engine combo so I reached out to Lenny at Ultimate to work his magic on a converter. It was also at that time I got a 598 that had been modified for a 1050. With those changes we went to Tucson in the winter and ran a 5.96 in some really crappy DA and 26.68 actually baro. Two weeks later at sea level (Irwindale) we went 5.79, but then wheel stood unloaded the rears, and hurt the car.

fast forward to last September at Famoso in 1800 DA we ran a 9.16 @ 145 and on one pass saw a 5.76 at the 1/8th which was another new best. That pass is with the Brett Miller R420-2 intake which is huge! I was hoping it would soften the hit, but we’ve gone a couple 1.22 60 times.

cam is a Crane core 264-272 at .050 108LSA .750 lift at retainer. I’m running leftover craftsman truck Jesel 1.6 rockers.


If you could find some mineshaft DA and a well prep surface good chance you get into the 8's. love your car.
 
Slo kid, what trans were you running before the 904?
 
So it doesn't depend on what's under the heads? It would be interesting to see 400cfm heads on a 318 and actually drive it I bet. I also bet it would leave one wanting. J.Rob
I’m thinking on a 10.5 416 inch engine... how much head is really too much
 
Cleaned up the heads and made an interesting discovery. What is causing 5 of the intake seats to erode? Is it water ingress and cavitation like seen on diesel cylinder sleeves. If it is where is the water coming from? Porous casting? Or is it the condensation and the hygroscopic nature of the alcohol pulling moisture out of the atmosphere? Or do I have it all wrong. J.Rob

View attachment 1715684280

Is that the short turn belly showing in that pic???? :eek:
 
Mind if I ask what is powdered metal ? Is it metal that starts out from a powder { Aluminum } ?
Powdered metal is caused by constant rubbing or grinding of metal surfaces from mechanical failure.
 
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