before i list my ra jo head on the classifieds, i would like to run it by you folks as to what model it actually is. i believe it is a model B head with maybe modifications. it has 1/2" pipe thd spark plug ports on one side only. the exhaust ports measure 1 1/2" dia and the intake ports measure 1 5/8" dia.it has 2" head dia intake valves and 1 3/4" head dia exhaust valves. it has been decked to 1" chamber height. any and all comments welcome. thanks
I believe it is a "B".
Before last week I would have laid money on it, this week I'm not so sure I would.
It's a B model, been milled quite a bit. A good head, looks nice and complete.
Since the head has pipe thread plugs on the intake side, it is not a BB. A BB has 18mm plugs on both sides plus the exhaust heat port. There are several articles on the NWVS site that confirm dual 18mm plugs on the BB.
Stuart's head is definitely not a BBR, so I would say it is a B. However, some one had posted recently that a B does not have the exhaust heat port. I have never seen a B but had always presumed it too had the exhaust heat port like the BB.
B heads have the exhaust heat port. The head pictured above has had it blocked off.
are those the real manifolds or new repos?, how much are you asking?
Erik, so are you saying the Model B and BB both came with the heating port and only the BBR did not have the heating port?
Tom, I believe this is a model B. No heating port and only a single set of plugs.
This is not to be confused with the model 31 which looks very similar to the Model B, except it has a recessed galley below the intake ports for short studs to mount it to the engine block.
Yes, that is my understanding. I have seen heads with 18 MM plugs both sides and the preheat port, that is the BB head. The BBR had higher compression and no preheat port. This is what I have been told by some big names in the T speed world. As stated before, I have seen a couple heads with an odd mix of features from several Rajo models, including such a head at Bakersfield a couple years ago that I think you picked up. I know of one close by here that has no preheat port and big intake ports, but the same compression ratio as the B head and only 4 pipe thread plugs on the right. Racine Joe was always looking to make his products faster, so there must be several variations from production heads. I had the pleasure or speaking with Joe's grandson. He told me it's pronounced Ray-Joe.
All this being said, I think Mark's Rajo repop head is a superb piece of work, better in many ways than the original, the compression ratio and valve sizes are much better for modern fuel and driving conditions. Want a Rajo? Buy a new one, bolt it on and haul a## with it. If you want an original, pay about the same money and then have it rebuilt.
I have no connection with Mark's Rajo repop project other than being a happy customer.
The Model T in Speed and Sport book (page 74) shows a Rajo B head with a heating crossover tube that goes over the valve cover from the exhaust manifold to the intake manifold and no heating port between the intakes.
The overhead valve article by Jarvis Erickson in the Vintage Ford (July/Aug 1983 page 29) shows an ad for the Model B with the heating port.
Maybe there was an early and late B head.
well, it seems as though it is some form of B head.
i'll go for that. i appreciate the comments.
Thank you for the positive words. I learn new and interesting things every day regarding RAJO head types and configurations. I am by no means an expert. I have learned there are no hard an fast rules when it comes to RAJO and what they offered. Only a consensus at best. On a side note, I have never located any RAJO literature identifying any head as a Model BB or even BBR. I have seen Model B, Model 31 (possibly an early B design)and Model B-8. I wondering if we fabricated the term BB and BBR just to make more sense of different variations of the Model B. Who knows? If anyone has any RAJO Model B style heads with other variations, please share so we may all learn.
The head in question is a Rajo B with the heat riser. I have run one on my speedster for over 25 years. I also have a early B that i think was used on a race car. It does not have the heat riser. Both heads put my cars in the 70 mile per range on the Woodburn drag strip. Lots of fun when you run against 1949 and 50 ford V8'S and beat them.