231/225 Discussion

Allright, this all got me started in my research after it was sworn that the 225 COULD NOT have a angled valve cover.

After pulling all 4 blocks out and cleaning the casting number to the point of being ledgable, here is the results:

Block 1 - B1358435 - 225
Block 2 - 1358435 - 225
Block 3 - 1249432 - 231
Block 4 - 1396736 - 225

All 4 engines are equiped with angled valve covers. Bellow are pictures of the valve train for them.

Here is a picture that is the same for 1/2/and 4


Here is #3


Here again is pictures of there valve covers:






Im not trying to light a fire here, but if its impossible to put 231 heads on a 225, and 225/231 valve trains are different, then how does all this come together?

 

Think I miss read the post.
Thats what happens when you take Nyqual and still cant sleep.


Interesting. I'll have to go look at mine.

 

you're not going crazy, here is what I have found.
all info from the Jeep parts manual.

pic 1 below clearly shows the 2 different cylinder head designs for the 225 V6, angled and not angled. At this point, no reason given for the difference. The footnote reference is 1-5 and 1-6 for the two styles.

pic 2 below shows the part number listing for replacement cylinder heads.
Note the V6 listing; only 1 part number shown for 1966-1971, CJ or Jeepster, doesn't matter. This contradicts pic 1 above. Note the lack of footnotes 1-5 and 1-6 for the two styles.

pic 3 below shows the parts listing for replacement valve covers. Note the lack of the footnotes again, 1-5 and 1-6, but do note the different part numbers for LDT (less dual throat carb) and WDT (with dual throat carb). First time we see that mentioned as far as heads and covers are concerned. Could that be the difference ? whether the engine came with a 1bbl or 2bbl carb ? this information suggests this.

pic 4 below shows the listing for replacement valve cover gaskets. Note the reference to footnotes 1-5 and 1-6 again.

footnote 1-5 suggests the original design and probably the most common type out there.
footnote 1-6 suggests a later design change for some unknown reason for right now.

In my opinion, for what it's worth, there is most likely a service bulletin letter out there floating around that could explain all this. Design change to the cylinder head for a clearance issue, performance issue or some other reason; the change in casting for the beginning of the 231 run ?

Just for info, there are only 1 type of rocker arms listed, the aluminum cast ones, not the stamped steel type.

Anyway, gonna sit back and watch now.

 

I have another source I will check out friday but I would almost bet that these motors were the boat engines and someone has used them as replacement motors or for the heads. Do your pushrods have holes in the ends ot them. Pull one of the rockers off and see if there are oil passages for the rockers to oil in the end rocker stands. The boat engines were made from 70 thru 75/76 if I remember correctly even though they were not used in cars.

 

I gotta admit I just stumbled on the pic of the head differences while looking for something else.....
that started the search for heads, valve covers, gaskets etc to clear this up.
I sold my marine manual a couple years ago......that was smart......
I thought the marine engines only used the 1bbl carb

 

1 of these was a 2bbl and the other 2 are after market 4bbl.

 

FWIW, the 2 pre-Dauntless 1bbl 225s I have have all rounded-corner heads.
...hoping scott milliner joins the discussion as I think he's got a marine version (229?).

 

dang, way to shoot my theory all to heck...

 

R) not so fast...it's just what I've seen which we all know doesn't amt. to much.

 

Both of those heads have stamped rockers - indicative of a 231. My 231 ('75/'76) has the angled corner heads and the stamped rockers. The castings are year matched per the our casting number table.

I'd suggest posting the the head casting numbers so we can verify.

Per Ganahal (V6 Performance) Any Buick V6 head will physically bolt to any V6 block regardless of even or odd fire motors, late or early style etc. The location of the internal passages and intake ports are problematic and care must be taken to ensure correct alignment of the various passages.

 

thats the impression i was under from my research. all you have to do is drill the holes to match, use the correct rocker assembly and push rods per head application and itll bolt and go. i was going to call TA performance to ask them but never got around to it. i might do that now and clean up my even fire heads and port my intake to match the new intake runners.
descisions, decisions...

 

I'm with Joel. My 231 has the angled valve cover and the 225 is rounded. I believe, as Joel said, these are all 231 heads as evidenced by the stamped rockers. Next...