I have a 308 engine with a cast iron (C.I.) head that has a little feature I've not seen before......an aluminum tag that was riveted to the head over the small, cast-in words "Power Dome" (not visible when the tag is in place). The tag reads "C.I. POWER DOME, Use Premium fuel. 305854".
The 305854 number looks like a good HMC # but doesn't come up in the '48-'54 Master Parts Catalog so I'm curious if someone knows what is different, if anything, about this head. A stock 308 CI head @6.7:1 certainly doesn't require Premium fuel so I'm baffled. It's on a pre-merger engine, thought to be a '52 and has the typical "H-145" cast in above the tag. The tag appears to be a factory issue piece and the characters are not free-hand stamped, I'd say.
Has anyone seen such a critter?
Frank
Frank, I think those were on the early 308s. I had one on my 51 Hudson Hornet that I believe was original to the car. It had a bad crack in it, and Jeff Perkins wanted to do some research on the capacity of the head.
Aaron,
I have a ton of 308 heads from '51 up(a bit of an exaggeration......but not much) but this is the only one with that Aluminum tag as I noted. I was just wondering why this particular head was wearing that tag specifying "Premium Fuel" and if the p/n told a story. If no one has knowledge of it, I'll "CC" the head some day and determine CR for myself. I might just have a "one-off"! Yeah.....right.
Frank
I dont think there is any difference between those and the later 308 heads. They were just the early heads that had those tags. Since I had one on my car, I have noticed quite a few either on cars or in pictures of engine online. Sorry, it might be rare unfortunately that does not translate to valuable... 😛
Aaron,
Oh, I wasn't delusional about the value of it, I was just curious as to the history of the tag since I hadn't seen one before. It may have originated in the marketing dept. to make potential buyers think it was so HP that it required Premium fuel. Who knows.....
Thanks for the input,
Frank
So is there any difference between the alloy tag head and the one on my '53 Hornet which has "Super Power Dome use premium fuel" cast into the iron?
Geoff, I will try and get a hold of Jeff Perkins. I sold him the cracked one I had (early 308 head with riveted tag attached) because he wanted to do some measuring on it, to see if it was any different from the normal 308 heads. I will see if he found anything out and post it here.
I was told the same thing as stated earlier. That those iron ones with the tag were the same as the aluminium high compression head. Due to Korean war shortage's they made some from iron,
Roger
Just to confuse the issue, my head has the number 305854 cast into it, which is one number different from the optional iron head listed in the catalog!
Full markings are "H145 in large letters, then Super Power Dome, Use premium fuel" below, and the number underneath. As mine is the only Hornet in N.Z, and was built in south Africa, I have nothing to compare it with. Just wondering if is higher compression, or did all heads have "Super Power dome" on them?
I wonder how "premium" fuel was evolving in those years. Maybe the normal fuel after the war was low octane, and the higher compression engines were needing more octane. I know compression ratios were all climbing in the '50's and the fuel had to follow. Looking at the heat riser passages in my Twin-H intake with a cracked flange, it appears they wanted plenty of heat to help atomize it in those years!!! In my high-performance endevors, I want to know how much compression these engines will tolerate with street fuel. Since my car will see no cold weather running, I want to eliminate the heat riser connection to the intake manifold. Cool air usually means more power, and I'm sure less percolation and vapor lock in the summer.
Bob I spent at least 30 min.replying to you and hit the wrong button and erased everything. Here is a short version. I havent had a heat riser in my 51 hornet for at least 30 years with no side affects. I dont drive it in the winter but have had it all over the USA in years past without noticing any differents. Gas, always bought the cheapest. If I could save 2 cents say pay 25 instead of 27 cents I would. I have put the 232 and 262 heads on my hornet and the only problem I had was blowing head gaskets with the 232 after running it hard. Never check the head for trueness, just took one off the pile. I hace timed the car by feel with out a timing light, set the points with a match book cover etc. Bottom line these cars are not high tech. cars and will run on anything anywhere. Their 60 years old just enjoy.
Bob, I hope Larry told you how he cared for his cars before you bought that sedan. Larry, did you use any baling wire to attach any of the main components to the car??? 😛
Thanks, Larry!!! I think that 232 head you gave me was the one that you tried at one time!!!! And I found the matchbook in the glove box, so I should be all ready to take it on that trip to Washington State this summer!!!! 😛
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