Ported 915 head results

[Garys1969RR]

Update on 451 with 915 heads, 509 Purple shaft cam. I had acquired a set of 915 heads last fall, they came with 2.14 intake and 1.81 ex valves. I ported them over the winter, using Mopar Muscle Magazine articles as a guide. Hit water in 2 intake pockets, repaired the 1/8 inch holes with Epoxy made for cyl heads. Had the (exhaust) valve pocket area opened up by a local machine shop. Also added Jegs headers to the engine. Now it has run a best of [email protected] MPH. Previous best last year with mildly ported 906s and HP ex manifolds was 13.74@ 102 MPH. Elevation of 5600 feet. So the headers, 915 ported heads and larger valves were good for more than a second and several MPH in the 1/4 mile. C/R increase was from 12.5 to 13.3 to 1. Cost of heads about $300.00, valve job and machine work $325.00, and about 40 + hours of home porting work. At $10 per hour, that's another 400. Valve springs $50. Epoxy $35.00. Total of $1110.00. So for a little more than what Stealth heads cost, I have good running iron heads. Which may flow almost as well as The Stealth does. Lol. But it was kinda fun getting it all done, and I learned a little.

 

[Sweet5ltr]

Nice numbers, 7MPH increase is a pretty solid jump in power! Did you get the Jegs 1 7/8th headers or the 1 3/4? This also shows how to most members, aluminum cylinder heads are a good alternative to getting deep into factory Irons from a price point. Converted through the NHRA's conversion chart, that is an 11.7 @ 117 MPH sea level..

 

[Garys1969RR]

Nice numbers, 7MPH increase is a pretty solid jump in power! Did you get the Jegs 1 7/8th headers or the 1 3/4? This also shows how to most members, aluminum cylinder heads are a good alternative to getting deep into factory Irons from a price point. Converted through the NHRA's conversion chart, that is an 11.7 @ 117 MPH sea level..

Using the Jegs 1 7/8 Headers. I believe they are made by Patriot as they look the same in pictures. Thanks for the conversion to Sea Level numbers. Another help in this combo, is with .017 below deck pistons, and .020 thick head gasket, I get a .037" squish area. The thinnest multi-layered gasket I have found for use with alum heads is .027". That would result in a .044" squish area. Would prob also work well.

 

[Sweet5ltr]

I'm running the same headers and they are made by Patriot if you check the part #'s. I have the ceramic coated ones, and they are honestly pretty nice and have been holding up very well! No complaints, and saved me quite a bit of money. With your C/R you should be running the .590MP solid.. It would probably make crazy good power!

 

[Garys1969RR]

I'm running the same headers and they are made by Patriot if you check the part #'s. I have the ceramic coated ones, and they are honestly pretty nice and have been holding up very well! No complaints, and saved me quite a bit of money. With your C/R you should be running the .590MP solid.. It would probably make crazy good power!

Yes I have been thinking about a cam change for next year! That .590 sounds like a good one. I am running a TCI street fighter torque converter. Around 3000 RPM stall. Would it work ok with the .590 cam? Ok Thanks

 

[Meep-Meep]

.590 is a pretty big jump. I'd be more inclined to run the .528 / 284.

 

[Garys1969RR]

Thanks, Meep. Since its running well, I am going to turn attention to body and interior work. If the epoxy head repair ever fails, then will prob go to some Stealth or Eddy heads. But so far so good.

 

[Sweet5ltr]

Yes I have been thinking about a cam change for next year! That .590 sounds like a good one. I am running a TCI street fighter torque converter. Around 3000 RPM stall. Would it work ok with the .590 cam? Ok Thanks

I would definitely go with a 4,000 stall. 3,000 is a bit on the mild side for a serious street/strip build. If you want to stay with the 3,000 stall, the .557 solid would probably work real nice. The .528 would make near identical power as the .509 hyd. you have in their now, but would probably idle like a kitten.. The .590 is right at around .570 lift with valve lash. That is very mild to me, but it makes great power in a street style cylinder head and has gobs of duration. If I was to go with a much larger port head, such as the 270cc Indy EZ, I would go with a .650+ lift roller or solid. The 210cc Edelbrock RPM's are great for factory cubic inch builds and maintain great port velocity. This must be in consideration at all times. For a 490+ci build, 270cc would be no issue.

 

[Garys1969RR]

Thanks 5 ltr, what kind of 1/4 mile times you getting out of your 69 RR with 451 engine? You make it to the track yet? Sounds like a nice build. Do you like the RPM heads? Are you using the Victor 440 intake? Does it fit on the 451 ok?