Howdy Guys! Does anyone know if Thickstun PM-7 Intakes Were made with Different Heights for the Hirise Portion of the Manifolds. Im thinking of getting one and ran into one that has the risers lower than all the rest ive seen. I realize it could have been modified but just figured someone might know something. As Always, Thanks for all the Input. BBOY
they had PM-9s? that were higher i think. i do know my friends carbs hit his generator so he needs spacers on his pm-7.
Does anyone know the history of Thickstun? As far as I know, Tommy Thickstun and Vic Edelbrock were friends! I wonder which came first though?
I had one that had removable 1" risers. Other then that, it was just the base. So t was a shorty version. Generator would not fit with carbs, but you could put longer risers on beings they were removable.
after looking it up i think i was wrong because i got wrong info. i think people could get them in different sizes or machine them down. the new ones they sell are a lot taller then my friends!
I think you're going to find that anything with shorter risers on a PM-7 has been modified. Based on the number of cut-down versions that I've come across over the years it seems like it was a pretty common practice...maybe for hood clearance? A PM-9? Jay Fitzhugh's very concise article about Tommy Thickstun in The Rodders Journal #8 is a great reference and doesn't mention anything after the PM-7. There was an early intake made without any real model designation and the PM-7 later. Maybe there would have eventually been a PM-8 or 9 but remember Mr. Thickstun p***ed away at a very early age and didn't get a chance to see all of his ideas come to life.
VI is right. I have done extensive research here, as I run a PM-7 myself. First, PM-7 stands for Pattern Mold 7. In all the original ads that i have collected on thickstun, i have never seen mention of a cut-down version. I think it was just the practice of the day to cut them down, either as hi-rises went out of style, or for clearance. I do have a strong belief taht after thickstun died, there must have been a large number of intakes with his name alraedy cast. Think about how many Thickstun intakes you see, for a guy who died in his mid-thirties in 1946. Bob Tattersfield renamed all of the Thickstun molds with his own name. It is my belief that Thickstun intakes after Tom's death were sold through bargain outlets, like Louie Shell. This is where some may have been sold as low risers. Anyway, to get the generator to fit, you have to use the early shorty generator. Hope this helps. Jay
I've seen so many lower versions that I have begun to wonder if it was not a standard offering. There are simply too many of them, in my mind, to have been simply modified - especially since they all appear to be uniform. I've seen two side-by-side and they're identical.
Ok, I read that PM 7 came in one height. I'm wondering if there is a difference in the Tattersfield. I've also read that a lot of the old racers would machine them at different heights to see which performed better and with which carb.. Duane..
Jay, that is interesting that research suggested only one size was made. I, also, would think that there were different hieghts made as I have seen quite a few lower. I don't recall seeing any that appear to be done poorly as you might think you would find. I agree that there must have been a large number of them cast ahead and machined much later. Thanks for the information. BTW I have an early block lettered Edelbrock which is the exact same heigth as the PM-7. Don't know if that means anything or not. probably just coincidence, or they may have used the same specs???
I have also seen a lower version, I thought it had been fitted in a boat! Heres mine Different filter now though!
Heres a marine version... notice the different plenum and body design, not just cut down and angled runners...
In reply to Scott Miller, I think that your manifold is the earlier model Thickstun which pre-dated the PM-7. The intake runners look like the older style. Perhaps they continued to use the older design for boat motors.
Scott, You have the pre-war version, which are much rarer. The only real third variation that I have seen is a unique single high-raise that was for a butane set-up, still with the Thickstun name cast on it. The only one that I knew existed was in the late Bruce Dahl collection (Great guy; God rest his soul).
PM 7s will have a "Paten Pending" on it, some have been filed off.. Scotts is the older model and could be for marine use..Most intakes used on marine engines had slanted flanges due to the angle of the engine.. Duane..
Actually from what I have read, the early Thickstuns were not that good of a performer. Apparently they had some very sharp angles in the runners which adversely affected flow. Supposedly that led Edelbrock to develop his own manifold.
The Jalopy Journal
