I recently acquire a complete Joe Gemsa engine built for Robert "DOC" Pruden who was active in the Signal Hill Climb races during the late 60's and early 70's. This engine appears to have very low hours on it. It is marked #11 with a 9-1 compression ratio rocker arm quad intake cylinder head, dual ignition system and full pressure on a modified counterbalance "C" crankshaft. Any information or photos regarding the history of this fantastic engine would be appreciated.
You should or might have a water pump mounted where that plate is on the front of the cylinder head. I have extra water pumps perhaps for that engine.
It looks like the water pump is mounted under the intake manifold, you can see it in the second pic. The flat plate with 8 screws at the end of the head is the back of the engine, right over the hogshead.
Rocker arms look like Ford Y block 272 - 292 - 312.
You know, I didn't even see the pedals, wow am I getting old . . . or is it only the eyes ?
Here is a proper Gemsa water pump.
La Rue Thomas new Doc Pruden had nine to one so he went one better and had two made with nine and a half to one compression
Here's a GEMSA that ended up in Florida
Not mine, but sure is a nice looking hot T engine.
Notice that your engine has the four bolt plate to cover the Model A type water pump mounted on the front of the cylinder head and is using a regular T type side mount pump.
Thanks for the photos Frank. I was researching past Vintage Ford articles on the hill climb and found a photos of Doc Pruden's touring with what appears to be the GEMSA #11 engine bearings his name. It even has the same T style water pump mounted on the side of the engine with the 1/2" drive shaft. The article stated he had the best time up the hill in his class for that year with this engine. Keep the photos and information coming. I'm planning on doing a complete restore; however, I'm not going to change a thing unless needed. I believe the engine should be kept as Joe built it for Doc back in 1969.
Thought I would update you all with the GEMSA engine rebuild. Aside from having to do a complete rebuild on the transmission (cracked drums and worn out bushings), the crankshaft showed no cracks. The rod and main bearing babbit was in fantastic shape. The unusual pistons were retained with new rings installed. Everything is coming along very well. Thought I would share a few photos of our progress. I will provide more as we move along.
Looks great, Mark.
Noticed the removable ears for your bands were on the passenger side as opposed to the driver's side as per Ford Manual ?
I wonder what was done to the transmission to handle all that power. It wouldnt seem like a stock tranny could handle all that power.
Good eye Steve! After checking the fit, the bands were installed in the proper orientation.
Yes Will. I suspect the transmission does take more of a beating with the added power and torque. That may explain why the transmission was in such bad shape and required replacement of the low speed and Brake drum and bushings. Two of the three tripple gear bushings were seized on the pins but turning in the gears. Probably set to tight from the start. Also, the Watts clutch disks were worn and replaced with NOS metal disks. A new heavy duty clutch spring was also added along with NOS brake drum clutch shoes.
Can you provide some details on the distributor? What is the model number and how are the point set up for dual fire?
I hope I am reading this correctly, Steve noticed that Mark had installed the band incorrectly. Mark thanked Steve for the good eye pulled them off, checked the fit, then installed them in the correct orientation.
I see in the picture the bands are incorrectly installed and should be flipped.
if joe numbered all his motors, how many exist?
Mike. I could lie and tell your it is a right hand drive trans cover but I won't. Yes, the bands are now installed in the proper orientation.
Tom. The distributor is a Delco-Remy dual fire distributor used on a 20's era Stutz engine mounted to a Bosch front plate. Without looking at the distributor, I recall the firing order to be as follows: 9 o'clock is #1 primary, 12 o'clock #2, 3 o'clock #4 and 6 o'clock #3. Secondary #1 is at 5 o'clock, #2 is at 7 o'clock, #4 is at 9 o'clock and #3 at 11 o'clock. Rotor secondary is offset 45 degrees.
Clayton. Joe did number all his engines. I've seen several in the 100 range. As this is number 11, it is an early example.
Hope this helps answer a few questions.
Back in June, I posted a few pictures of GEMSA #11 as it was found in a local collector's shop where it had been sitting undisturbed for over forty years. Today, the complete restoration was finally completed. I'm sure Joe would be proud! It will soon be made available for purchase.
Wow that is one hot looking engine Mark!
Well done on completing such an excellent restoration.
I wonder what type of transmission bands were originally installed in the engine since it was built and used in the late 60's and 70's. Interesting!
Probably the same stuff they used for the AC or Rocky Mountain brake liners! Lol, need something serious for that rocket.
I really gotta make more money. I would LOVE to buy that engine and then build a nightmare of a speedster around it. A Warford and a Ruckstell with 3:1 gears? That car might go 100 mph.
Hey Mark - what kind of cam did you guys put in it? Or is there a specific "Gemsa" cam?
Mark, What is the story with the spacer between the Hogs head and the engine block?
Mike I've seen spacer's like that when they are fitted with a model A crank
The brake and reverse bands were Scandanavia type material while the low speed band utilized a material similar to the outside brakes.
The camshaft is a GEMSA modified model A with significant lift, duration and dwell.
Spacer (and other alterations) allow a Model A size crankshaft to be fitted to a T block without cutting the crankshaft to shorten it.
We saw this on the trip to Chaffins last week but didn't want to post any pics or say anything about it before Mark posted. It is a work of art.
Then the oil pan must then be lengthened? What is done to correct the gap between the arch of engine block and hogs head?
I just looked at he previous pictures. The oil pump adapter acts as a shim to make as a filler for the block to hogs head arch. Then the oil pan is cut and looks like a section is added.
Stan, Sorry to have missed your visit. Would have been nice to visit with you.
The block to pan mounting bolt holes are also moved forward (about 1/2 inch along with the front crankshaft dam / support. The oil pump bracket also acts as the new surface to mount and seal the trans cover. Pretty good idea to allow for the crankshaft to remain unmodified.
That is one beautiful engine!!! I'm not really a Speedster guy, but I could become one with an engine like that to build one around.
Moving the block ahead on the pan is a common way to install an unshortened A crank in a T block.
The front dam is removed and moved ahead 5/8" and the pan bolt holes are redrilled to match. A 5/8" thick spacer is added to the field coil area/rear of the block so that the hogs head can seal. Essentially the transmission sits in the original location with everything else moved forward.
That's how mine is done in the Racer - full length "A" crank.
Another way to modify the pan to move the engine ahead is as follows;
1. I took a extra late style 3 dip pan and cut it near the back of the inspection cover hole. I then cut the 4 dip pan so it would all fit together and be 5/8" longer and welded it up. I then had to weld up and re-drill a couple of holes to fit the block at the back.
2. Now I removed the front engine mount from the outside and re installed it on the inside of the pan at the front. Miraculously it takes care of the 5/8" that has been added into the pan.
I am sure not saying it is a better way, just another way to get there!!
Very nice job Mark. I went the other way and shortened the crankshaft in my engine. Has been together now for 30 years.