Cylinder head interchange

hudsontech

Seems to me there was some discussion about interchanging cylinder heads - in backing up my Hudson files the other day I came across a bulletin that addressed this.



General Technical Policies and Information Bulletin No. 14, issued 7-2-51 gives the following info for 1951 Hudsons:





P/N 304618 - Cast Iron 232* - Model 4A, Standard Fuel; Model 5A-6A-7A, use high octane fuel;



P/N 304622 - Aluminum 232* - same as 304618;



P/N 304620 - Cast Iron 262* - Model 5A-6A, Standard Fuel; Model 7A, use high octane fuel;



P/N 304624 - Aluminum 262* - same as 304620



Use of 304620 and 304624 on Model 4A will reduce compression ratio and give less than rated hp;



P/N 304629 - Cast Iron H-145* - Model 7A, Standard Fuel;



P/N 304631 - Aluminum H-145* - same as 304629;



P/N 305854 - Cast Iron H-145* - Model 7A, high octane fuels



* Numbers cast on top of head near front end.



Use of 304620 and 304624 heads on 4A will reduce compression and give less than rated horsepower.



Use of 304629, 304631 and 304854 heads on 4A, 5A or 6A will reduce compression and give less than rated horsepower.



Don't know how this applies to 1952-1954 models - there's probably other bulletins that I don't have.



Hudsonly,

Alex Burr

HudsonTech

Memphis, TN





*Numbers are cast on top of head near front end:



Hudsonly,

Alex Burr

HudsonTech

Memphis, TN

SuperDave

Thanks Alex'

Copied and filed.. Dave W (FL)

hudsontech

SuperDave wrote:

Thanks Alex'

Copied and filed.. Dave W (FL)

Super Dave - you want a copy of the whole bulletin drop me an email and I'll fwd a copy. It's only one page.



Hudsonly,

Alex Burr

HudsonTech

Memphis, TN

NEChudsontech09@yahoo.com (Drop the NEC)