[JKrull66]

Lookin good!

[R 70 Judge]

Originally Posted by Jim Robertson

5.9s would be great but 5.8s would be better :-) And we are a long way from Norwalk geographically and performance wise, but I am trying to bring it.

Hi Josh, 79 Hood and nose are in great shape and need a new home.

For the Painters, we worked extra hard on the nose, shaker and stripe but the launch pic does not show the factory stripe so here is an little better shot.

Car looks great, Jim!

[jm455ho]

Very nice. Great color and stripe combo. Nice to see some can enjoy track time. We got 8" of snow the last couple of days.

[duke455]

I know this has been on here a while but what kind of epoxy are you using and where
is it avalible from. Thanks Mike

[10secbird]

Had to bump this one up

[10secbird]

I love this project of Jim's. These 48s got to be the baddest d-ports on the planet. And I used think my 48s were modified

I love the approach to porting he took on these 48s, to me the approach seemed to be....I am going to make this port shaped the way I feel it needs to be shaped, I'll worry about patching holes later.

I'm not trying to make the approach sound oversimplified, I just like that he wasn’t afraid to create major holes in the ports if that’s what was required to get the port shaped and sized the way he wanted it, and that he had a lot of confidence that he could close the port back up using whatever methods. It takes a lot of balls to do a port job like that. We are talking a lot of patience and commitment to see a project like that to completion, considering at one point after investing considerable amounts of time grinding, the ports are filled with massive holes that you’re not 100% sure you can fix and to what degree of reliability can you fix them.

And to think someone is giving that much TLC for a lowly obsolete iron cylinder head, while it was no less effort than what is performed by the R&D department of a champion ProStock team porting and modifying a cutting edge modern cylinder head. That is what makes this project cool.

What motivates one while they are performing the overly tedious and monotonous task of porting a set of cylinder heads, grinding for 30, 40, or more hours? It is the thought that he is creating horsepower as he grinds, gaining a horsepower advantage over the competitors, that they are creating something unique that no one else will have, in this case, a unique horsepower advantage that is his own. I think in this case Jim probably feels pretty confident that; few if any, are going to match the time and effort, (let alone, skill) he did modifying a set of D-port Pontiac heads, and that he most likely has now and in the future “The baddest D-ports on the planet”

Jim, do you have any pictures showing the epoxy work and all the places where you ground through. I would love to see the extent of the holes in the intake roofs and how you did the epoxy work... like a nice detailed shot under the valve covers near and around the rocker stud bosses. Also, you stated that you hit water. Was the water hit in the intake ports or the exhaust? I think that grinding through to a water jacket would be the most challenging holes to patch as you generally can’t get behind them and water will soften and deteriorate the adhesion of the epoxy.
Every time I see the picture of the intake port, I laugh because it is so radically enlarged, causing an initial reaction of …WTF OMG. Those are some badass looking intake ports

I also take extra interest in this because I run a set of 48 heads that have extensively ported intake ports, with roofs that have been ground through and patched with epoxy. Up until seeing your max ported 215cc intake volume, I thought my intake ports were pretty maxed out, with a ported volume of 177cc. My ports are only half way there…..holy intake port Batman!

[RAMAIR RICK]

Jim you have designed, and ported, not only a very cool car, but a very impressive engine, that does exactly what you wanted it to do. That being said, how TAME of an engine would you want to build if it was say a 540-545ci, PUMP Gas 92-93 octane, 11.25-11.50 static compression with any heads that you could choose? Example, ProPorts, Tigers, High Ports, DCI Ram Air V's, etc. to get a 800-850hp street/strip engine that could be very low maintenance?? Thanks in advance for sharing your thoughts. I think many people would LOVE to truly have an engine NA that would do it all.

[Jim Robertson]

10secbird,
Thanks for noticing the extra work in these and for your kind words. With all the head choices now days I did not think anyone cared about the lowly iron D ports. Seems like an eternity since we started in on those 48s. I have some in-progress pictures of the carnage and will try to post. Definitely was trying to get to a size and shape that I had envisioned. The shape that the 66cc (starting size) chamber allows is very important to the resulting performance in the car. This engine accelerates very easily for some basic OEM parts. These iron heads really like alcohol fuel.
Sealing the water was the most challenging...they still seep just a bit. Because of the location of the water holes on the deck surface we were able to place the epoxy in the water jacket just where we needed it. We concentrated the heat in specific areas to get it to flow in place. If you look at the inside of the port we only broke thru just past the head bolt column. Had to make a big hole in the water jacket wall in that one location to get to the width we wanted. Obviously hit head bolt, pushrod, rocker stud hole, and valve cover bolt hole but we did not grind thru the roof (except one pin point), walls or floor otherwise. Roof is thin so we reinforced it with a bit of epoxy. With the minimal roof remaining I felt the intake rocker stud boss structure could have been compromised so I tied all the studs together with steel bar stock. We milled all the bosses the thickness of the bar stock and that now sandwiches between the rocker studs and the milled bosses. If you look closely at the stock rocker stud holes the threads begin about 1/4" into the hole. The picture shows the rocker bosses after the milling.

[Jim Robertson]

This is an older shot as we were experimenting with additional width at pushrod and floor filling.

[Jim Robertson]

This shows the bar connecting the stud bosses.

Best 1/4 mile performance so far is 9.48 at 143MPH...60 foots suck.

[10secbird]

I still look at these heads and just shake my head in disbelief ... Love it

[blueghoast]

For Real: Talk about eye candy, Man I could stare at them all day.
Nice

GT.

[Johnny406]

Originally Posted by Jim Robertson

This shows the bar connecting the stud bosses.

Best 1/4 mile performance so far is 9.48 at 143MPH...60 foots suck.

Pardon my ignorance but does this bar stiffen the stud bosses kinda like a stud girdle would?

[J.C.you]

Originally Posted by Jim Robertson

This is an older shot as we were experimenting with additional width at pushrod and floor filling.

how did filling the floor work out? Any improvements?

Looks like a shaft system would be nice.

[Jack Gifford]

Originally Posted by Johnny406

... does this bar stiffen the stud bosses kinda like a stud girdle would?...

In post#208 above, Jim explained that the bar is "insurance"- as removal of head material under the stud bosses left the studs without their normal amount of thread engagement in the head.

[Johnny406]

Originally Posted by Jack Gifford

In post#208 above, Jim explained that the bar is "insurance"- as removal of head material under the stud bosses left the studs without their normal amount of thread engagement in the head.

Oops, I missed that...

[Jim Robertson]

Jack sees it basically as I...The port roof material was extensively removed so we devised a reinforcing method (insurance I suppose) to tie all the rocker stud bosses together. It seems to be working pretty good. However, on the thread engagement subject...even though we machined stud boss material away, we have the same amount of threads in the stud boss as Pontiac designed and installed in 1969. We used the same part number rocker stud as we use on all iron head stud girdle applications. The Crane stud mount Gold race rockers have been very reliable with no issues as has the Jomar girdle. Valve lash has remained very stable such that I have not had to adjust valve lash in two years.

Floor filling pic was early in the evolution and exceeded our velocity design for this engine so we continued grinding. The chosen parts in this old stud mount roller rocker/pushrod guideplate design are working so well a shaft system is not necessary...on second thought maybe that is what is holding the engine back...

The pic is from another angle showing the bar stock used to tie the stud bosses together.

[RAMAIR RICK]

Jim, nicely done, well engineered and performs as such.

I wonder what will happen with those DCI Ram Air V heads in YOUR HANDS????