BBM Head Swap

[SE2839]

All of the parts are here and so the engine will come out next weekend for the upgrade. As a precursor to doing my BBM head swap I took my Comet up to Anderson Ford Powersports in Clinton Il. to establish a horsepower baseline on their chassis dyno. With the C6AE-R iron heads still on the car it put down 309hp at the rear tire. I did not tune it prior to putting it on and did one hit as driven. A follow up dyno run & tune will be done to determine the gain once the new heads are installed and then tuned for max performance by Ron Anderson.
Werby has run a Gonkulator on the expected gain with the BBM heads and estimates 539hp/530t at the crank and 365hp/388t at the tire. In a couple of weeks we'll see if the actual data backs that up! In the mean time pics will be posted as progress is made.

Edited to add videos, embedded did not seem to work here so posted URL. Let me know if there is a better way to share.
http://www.supermotors.net/getfile/1033626/fullsize/afp-baseline-309hp.mp4  Short Clip

Better 2 Minute Video
<embed src="http://www.supermotors.net/includes/video/player.swf" width="480" height="326" bgcolor="#ffffff" allowscriptaccess="always" allowfullscreen="true" flashvars="file=http://www.supermotors.net/getfile/1033832/flv/103/1033832.flv&image=http://www.supermotors.net/getfile/1033832/fst/1033832f.jpg&aboutlink=http://www.supermotors.net/registry/media/1033832&abouttext=See this video at SuperMotors.net" />

[bn69stang]

Looking forward to the feedback Ed , keep us in the loop .. Bud

[SE2839]

Day one of the swap and it was just short of a disaster. Got a late start and I was a bit apprehensive but slowly and methodically removed and disconnected everything that needed to be. First snafu, I used a different lifting device which I would not use again but with persistence and perseverance and just a little damage to the core support that will be easily straightened but will require repainting I was finally able to get the engine out. The tear down went smoothly with no surprises nor issues other than the mess which was expected and once that was dealt with prepping for the new heads was begun. Second snafu, I compared the header to the gasket for the new heads and discovered that this header absolutely will not work. Several people have made statements that the two would interchange but that a bolt hole or two `would require being elongated and others have suggested that this was not the case. Those in the latter group are correct.
A) the difference in the floor and ceilings are close to a quarter inch off from one another.
B) the FPA's headers flange is already slotted and ends below the ceiling of the CJ port and so would require being plug welded so as not to have a huge leak.
Given the mismatch and how that would kill the flow I will be ordering new headers next Tuesday. In the mean time engine reassembly and installation will continue and some of those things which were waiting for winter may be completed dependent upon how long it will take for the new headers to arrive.

Anyone looking for a set of headers to fit GT heads?

[ScotiaFE]

Which header will you use?
I know the Hookers will fit the BBM port, but have the slight hang down issue
and the big Hookers have even more of a slight hang down issue.

[Drew Pojedinec]

and the big Hookers have even more of a slight hang down issue.

We ran into that problem in Panama.... but ya know, sometimes ya just gotta make do with the situation.


Seriously tho, SE2839, thanks for posting all this, keep us updated, I'm curious to see what kinda effect these heads have over the ole trusty iron.

[My427stang]

Well, hate to see you have to spend more money, but some good things to know

1 - The FPA headers for a CJ head should be the same header with a different flange, so it should bolt right up

2 - The higher exhaust port should be more efficient, so think of it as more power on the table.

I think you are in for a check of difference, looking forward to the results

[SE2839]

I had a good friend offer up his set of Hooker Comps, he built a 427 based stroker and upgraded to the Doug's with crossover tubes. he is shipping them via Greyhound so progress will be back on track with just a slight delay and another slight deviation to the comparative data. New dyno numbers will include head swap, roller rockers and now headers.

C6AE-R heads to BBM
OE adjustable rockers to Harland Sharp
FPA headers to Hooker Comps

[JamesonRacing]

Just as a FYI, the Hooker Fairlane/Cyclone headers are not approximately symmetrical right to left: the right side exits quite a bit farther back than the left side, and the tubes for 5/6 go underneath the lower control arm, so are vulnerable to speed bumps.  So you'll be doing a bit more exhaust system work to connect the Hookers.  You'll also notice a decrease in weld and fabrication quality between the FPAs and the Hookers, at least that's been my experience.  If the Hookers don't work out for you, drop me a note....I have a good set of used FPAs for CJ/aftermarket heads that I have stored waiting to go on my convertible, but that's a long ways away.

[SE2839]

Thanks to the kindness and generosity of good friends and fellow FE enthusiasts I now have two sets of headers for the CJ pattern. Thank you to Bill n Diane (other forum) and David Jameson without your help this project would have had a very long delay.
Today saw the valve clearance checked  and the heads installed, I did find a clearance issue with the Harland Sharp end stand hitting the ARP head bolt but a quick pass on the bench grinder and cleanup with a file was all that was needed. I have decided that while the engine is out I will do the front end upgrades, I've had the parts but had been waiting for winter but with the engine out it will make doing the Shelby drop much easier not to mention how much easier the engine will be to drop in without the steering in the way.

GT vs CJ ports-

Engine pulled for swap-

Head on-

End stand clearanced for ARP stud-

Intake sits roughly .030 above head at valve cover-

[blykins]

You may want to take the intake and have the valve cover flanges milled down.  A .030" step is more than what I'm comfortable with. 

[Joe-JDC]

How much difference is there when you torque the intake down?  I would torque it in place and measure the difference before cutting anything.  The torquing of the intake will leave an imprint on the gasket which will tell you how the intake if fitting around the intake port.  If there is a mismatch upper and lower, then you will need to cut a small amount off both sides of the intake manifold to get a better fit/match.  Joe-JDC

[blykins]

Yes, and also check port alignment. 

[SE2839]

I've been working a lot of overtime the past couple weeks so not much time on the Comet this past weekend, I did manage to mount the intake and probably used too much RTV in the process. I ended with a difference of between .021 and .033 between intake and head at the valve cover surface. Port alignment looks good, bolts were not aligned well at first but my weight applied to the intake displaced the sealant enough that they lined back up. Engine is just about ready to go back in but first a little front end work. Hope that I never need to take it off again.

I took a little time out and worked on starting the '63 Fairlane that will be the next project. Planning to build it into a gasser using the 390 that was once in the Comet. It has been sitting for more than 25 years. pulled the plugs and fogged cylinders with WD-40 allowed it to sit over night then spun the engine with plugs out. reinstalled the plugs bypassed the tank, poured a bit of gas down the carb, cranked it and its little 260 came to life.

[machoneman]

Wow SE, I wish I had a garage that big!

[mlcraven]

Crikey...nice set-up!! But a French tire sign?