M38A1 vs M38 Carb base gasket and diffuser

jameydan · Post by **jameydan** » Mon Dec 05, 2011 11:39 pm

Did the M38A1 use the metal "V" diffuser as did the L head engines? My 53 M38A1 came with an aftermarket carb, and I am now bring the fuel system back to original with a rebuilt YS carb.

See this post to see an image of what I am talking about (Wes K's post, forth one down): http://www.willysmjeeps.com/v2/modules. ... highlight=

Should I install the gasket "dry" or use any permatex-type non hardening sealer - or other sealant ?

Thanks.
Jamey Williams

Post by **wesk** » Tue Dec 06, 2011 2:05 pm

No, The M38A1 intake is integral in the head and the carb and the mixture are warmed very quickly.

Post by **wesk** » Tue Dec 06, 2011 2:12 pm

Should I install the gasket "dry" or use any permatex-type non hardening sealer - or other sealant ?

This is a topic I always take serious issue with. The professional industry standard is to always follow the vehicle and gasket manufacturer's instructions. If they conflict with each other that can be sorted out by contacting the manufacturer. Gaskets are designed and built to do their job. They seal things. Individual seals and gaskets may or may not be compatible with chemicals used in sealers and adhesives. If there is suppose to be an addition of a sealer to the gasket it will be clearly stated in the manual for the jeep or the paperwork that came with the gasket.

Adding sealant can often cause a gasket to perform poorly. A good example is a gasket that is now slippery will shift as you attach and tighten the mating part. Sealant that oozes out the edges can often contaminate the media your gasket is suppose to contain.

I never use a sealant on a gasket unless the instructions say I should or I determine I have imperfections in the mating surfaces that need help sealing with the gasket.

jameydan · Post by **jameydan** » Tue Dec 06, 2011 3:30 pm

Wes,

Great info on the choice to use a sealant or not. I was leaning towards not, as I did not see anything that indicated to use it in the TM manuals. I spent a lot of time last night looking thru the manuals, and part of the reason is trying to learn how to use the manuals and understand their format. For a newbie to the manuals they are a little more comprehensive then the typical chiltons type manual.

Thanks again.

JW

Post by **wesk** » Tue Dec 06, 2011 3:49 pm

The Chilton, Haynes and etc were designed for the at home "Do it your selfer".

The Military manuals are structured a wee bit different than the civilian manuals and this structure has a tendency to make it tougher for a civilian that has no military time to grasp how they flow right away. The factory Willys/Kaiser manuals are more civilian friendly and in some areas of data are more complete and easier to understand than the military manuals.

I always advise M38 guys to go with a copy of SM-1002 and the A1/170 guys to go with a copy of SM-1046.