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Rajo-head questions

Posted: Wed Mar 25, 2020 3:45 pm
by Anton Seelmann
I am currently starting a complete overhaul of my 13 Speedster with Rajo-Head and need your help.
First question: is it possible to check the valves for opening and closing with respect of piston travel. Or is there another method and if so, with which values?
Secon question: How tight should the head bolts be (first time, second time and finally)?
Many thanks to everyone
[image][/image]

Re: Rajo-head questions

Posted: Wed Mar 25, 2020 4:14 pm
by Erik Barrett
I set valves at .012” intake and .014” exhaust at TDC compression stroke. Torque head at 25, then 40, then 50 lbs/ft. if you are using the early block. Go to 55 lbs/ft if you are using a later block. Retorque several times until it holds torque.

Re: Rajo-head questions

Posted: Wed Mar 25, 2020 4:18 pm
by Joe Bell
I used stud so less chances of pulling threads on the block, the studs have fine thread on the top side and used hardened washers.

Re: Rajo-head questions

Posted: Wed Mar 25, 2020 4:19 pm
by Joe Bell
I know they are not the engines I use to play with but I would hate to lift the head on compression.

Re: Rajo-head questions

Posted: Wed Mar 25, 2020 4:39 pm
by Anton Seelmann
Erik, many thanks for your answer/service. Early block is 1913? Engine-number: C171352; its a canadian serial number from August 1918 (Bruce Mc. Calley). I will start my project tomorrow. May I ask again if there are major problems?

Re: Rajo-head questions

Posted: Wed Mar 25, 2020 4:53 pm
by Erik Barrett
Certainly, and as suggested it is a good idea to use studs and nuts. Dan McEachern has them.

Re: Rajo-head questions

Posted: Wed Mar 25, 2020 5:18 pm
by walber
Not sure if this helps but if Dan is out of stock on the studs, and if the deck height is the same as on a Fronty, the long studs for a Model A engine work just fine. I used them with my Fronty so I could ensure full use of the threads in the block without needing to do any grinding or modifying of head bolts. BTW, with the studs having fine threads, I still torque to 50 fl/lbs on the nuts which would be a higher torque value than I would trust torquing bolts in the block. Other opinions may vary but this has worked fine for me.

Re: Rajo-head questions

Posted: Wed Mar 25, 2020 8:43 pm
by Dan McEachern
Eric's advice is pretty much spot on the money. Studs are nice, but you need to have sufficient fire wall clearance to get the head on and off and that might not be possible in this case looking at the picture. You really need to measure your head for the correct length studs as some heads have been surfaced a bunch etc. Walt is correct that long A head studs will work in many instances but. I have a pretty fair assortment of studs in stock for various heads, but it all depends on the length you need.

Re: Rajo-head questions

Posted: Thu Mar 26, 2020 11:23 am
by rnkugel
I have the same head on my 26 Speedster. Anyone have a good way to get to the 5 bolts that are behind the exhaust/intake manifold for a re-torque? I have a very expensive NOS copper gasket and would hate to remove the manifold for re-torque. Thanks

Re: Rajo-head questions

Posted: Thu Mar 26, 2020 1:28 pm
by Dan McEachern
You probably have no choice, but resealing the manifold gasket should not be an issue. Some hi temp RTV will seal it. Since MOST of the clamp pressure to seal the cylinder bores is done by the two rows of bolts directly adjacent to the cylinders, retorque those for sure if you don't want to pull the manifold, but it certainly would be best to retorque all of them. In hindsight, with a new head gasket- put a junk manifold gasket on there until you pull it to retorque the head and then put on the manifold gasket of choice, but you're past that point now.

Re: Rajo-head questions

Posted: Mon Mar 30, 2020 3:55 pm
by Anton Seelmann
where can I buy a manifold seal as in the picture for my 8-valve Rajo?
And thanks to Erik Barret, Joe Bell, Walber, Dan McEachern for your comments.
Sorry for my Bavarian English
manifold-gasket (Small).JPG

Re: Rajo-head questions

Posted: Mon Mar 30, 2020 4:07 pm
by Dan McEachern
Anton- no one makes new intake/exhaust gaskets for that Rajo head. Simply reuse the old one with some high temperature RTV around the port openings. If you need a new one, your only option will be to cut one from hi temperature gasket material. McMaster-Carr offers some Kevlar material that works quite well, and something similar should be available in Germany.

Re: Rajo-head questions

Posted: Mon Mar 30, 2020 4:24 pm
by Anton Seelmann
Dan, thanks for your answer!

Re: Rajo-head questions

Posted: Mon Mar 30, 2020 6:40 pm
by Tracer
Is that a model 30 or c35 Rajo please ?

Re: Rajo-head questions

Posted: Tue Mar 31, 2020 12:06 am
by JSteele
It's a Model C

Re: Rajo-head questions

Posted: Tue Mar 31, 2020 2:48 pm
by Anton Seelmann
It is a model C (but stamped is T or bad stamp?) 35; production-number 8546
rajoC35 (Small).jpg
my speedster at the moment
speedster-now (Small).JPG
my speedster in december 1919 with my dog Mona (she has a racing driver license)
mona (Small).jpg

Re: Rajo-head questions

Posted: Tue Mar 31, 2020 3:01 pm
by rnkugel
Anton-
I got a NOS gasket for my C-35 head from Olson's Gasket in Washington.
Phone: 360-871-1207
Not cheap, but if want original he's the only place I found.
Good luck