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Bathtubbing heads

Started by xlfan, September 07, 2023, 10:46:13 PM

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xlfan

Has anyone tried to bathtub the shovelheads and run flattops? 

rigidthumper

My buddy Dave did that back in the 90s. Inspired from Jerry Branch's heads. IIRC, he used Evo cams & lifters, Crane 316-2, and made just under 100HP/TQ.
Ignorance is bliss, and accuracy expensive. How much of either can you afford?

fbn ent

I had that done back when. Didn't dyno it but it was fast! A word of caution though...mine started cracking to the point I couldn't keep a head gasket in it. It could have been heat, old castings or poor welding procedures. It has S&S heads on it now.
'02 FLTRI - 103" / '84 FLH - 88"<br />Hinton, Alberta

SP33DY

September 08, 2023, 11:03:20 AM #3 Last Edit: September 08, 2023, 01:51:32 PM by FSG
I did one a long time ago. It ran pretty good! I used Evo pistons and oversized Rowe thin stem valves, but I don't remember the size. If I had the time and inclination to do it again, I think I would use Axtell style angle dome pistons and bevel the combustion chamber to match. That way I could unshroud the valves a little bit more and keep the C.R. up.

JSD

Baisley did em on shovels years ago . 

JW113

Of course it can, and has, been done. Back in the day Shovels were all there was to work with, and yes that was a technique to get more power. Click ahead three generations of big twins, and today you can get far more power if that is what you are after. The problem with Shovels is the 45 degree valve angles, along with the way too big ports which kills velocity. Yes, with lots of money those can be improved, and yes, back in the day it was done. Just my opinion, but if you want a Shovelhead with a lot of power, go for displacement. Like a 108 cube or such.

But if you are a good machinist and aluminum welder, give a go at the heads. I would not suggest doing it with the stock heads, though. The aluminum they used back then was crap....

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

DA71FX

I think JW hit the nail on the head.....Even if I had a set of later heads like clean NOS pieces, I would save them for a resto and use a set of S&S or Ultima castings since they will be heavily modified. Wow, it seems like just yesterday when these were available from Branch and STD.....I am feeling old again.
93", 71 FX, 93" 56FLH

turboprop

Quote from: DA71FX on October 02, 2023, 05:52:45 PMI think JW hit the nail on the head.....Even if I had a set of later heads like clean NOS pieces, I would save them for a resto and use a set of S&S or Ultima castings since they will be heavily modified. Wow, it seems like just yesterday when these were available from Branch and STD.....I am feeling old again.

Jerry Branch never made shovel heads. STD was sold to Nitro Billy and he was making shovel and pan heads under the STD brand name. Not sure if he and/or Von Steg are still making shovel heads.
'We' like this' - Said by the one man operation.

billbuilds

     Sorenson Performance, when $ is not an obstacle.
Anybody who tries to tell you that the press is the enemy of the people is just that.

Deye76

"Not sure if he and/or Von Steg are still making shovel heads."
Or those nice Pahheads with the 3 bolt ex. flanges that fit shovel cylinders.
East Tenn.<br /> 2020 Lowrider S Touring, 2014 CVO RK,  1992 FXRP

DA71FX

Quote from: turboprop on October 02, 2023, 07:29:31 PM
Quote from: DA71FX on October 02, 2023, 05:52:45 PMI think JW hit the nail on the head.....Even if I had a set of later heads like clean NOS pieces, I would save them for a resto and use a set of S&S or Ultima castings since they will be heavily modified. Wow, it seems like just yesterday when these were available from Branch and STD.....I am feeling old again.

Jerry Branch never made shovel heads. STD was sold to Nitro Billy and he was making shovel and pan heads under the STD brand name. Not sure if he and/or Von Steg are still making shovel heads.
Branch didn't make them, but they did offer the service of welding up good cores that the user provided and bathtubbing them. But that was decades ago...
93", 71 FX, 93" 56FLH

98s1lightning

If money is no object, you got SPEED & SCIENCE co. To look at. They have some good videos on the tube, and have put a lot of research and testing into their products.

turboprop

Quote from: DA71FX on December 16, 2023, 07:50:29 PM
Quote from: turboprop on October 02, 2023, 07:29:31 PM
Quote from: DA71FX on October 02, 2023, 05:52:45 PMI think JW hit the nail on the head.....Even if I had a set of later heads like clean NOS pieces, I would save them for a resto and use a set of S&S or Ultima castings since they will be heavily modified. Wow, it seems like just yesterday when these were available from Branch and STD.....I am feeling old again.

Jerry Branch never made shovel heads. STD was sold to Nitro Billy and he was making shovel and pan heads under the STD brand name. Not sure if he and/or Von Steg are still making shovel heads.
Branch didn't make them, but they did offer the service of welding up good cores that the user provided and bathtubbing them. But that was decades ago...

Everyone knows that. The issue is your post implied that Branch was somehow comparable to STD and manufactured heads. Nothing could be further from the truth. In fact, there are many shops that have welded up shovel heads, they just were not the expert marketeer that Jerry Branch was.
'We' like this' - Said by the one man operation.

DA71FX

I want to clarify that I didn't intend to imply that they are equivalent. I was merely pointing out that, at one time, various options were available for those interested in pursuing that path. I don't believe any mass-produced item from that era could match the quality of Branch Flowmetrics, Baisley Hi-Performance, or some of the other highly skilled cylinder head specialists. It's a bit nostalgic for me to reflect on those times when there were multiple choices, and it's surprising how quickly those decades have passed.
93", 71 FX, 93" 56FLH