issue's with my hybrid 231/225

let me state that first off I didn't realize exactly what I had before I went into this adventure. however I now think that I have figured out what I have, will it work.

this is what I posted to a different site before I did some research on this site and found the thread "HELP! 225/231 block compatibility" however there was no resolution posted to this issue.

my postings to a different site (jeepsters: american jeepster club) are below



my problem is this
I had a student at the vo-tech (I'm a teacher) check the motor out and re-assemble it. he installed it in the jeepster and I brought it home thursday, however it had a wierd squeak/chirp from the upper end on the pass side. I pulled both valve covers off and notice that there wasn't any oil pools in the heads. when I oiled a pushrod the chirp/squeak went away. I've taken the rocker assemblys off and checked them to see if they were plugged up and cleaned them out. I then ran a wire thru the head and it seemed to go to about where the block would be. I then remounted the rocker assemblys and the chirp comes and go's. how much oil flow should there be in the upper assemblys (there seems to be none) and what would you check next. any idea's suggestions would be great. I'm wondering if they somehow accedentally blocked off the oil passage between the head and the block. Does anyone have any idea's or have run into this problem before?

Thanks
Brad J
jeeptchr@hotmail.com

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I'm assuming the whole engine was apart. Did they pack the oil pump with vaseline before it was assembled? Buick engines whether V6's or 8 are notorious for not picking up oil on started up after reassembling the oil pump. They need to be primed. A quick way around not having to take the oil pump apart is to remove the oil pressure gauge and squirk oil into the oil passage so it gets back down into the pump. The heavier weight the oil the better, like 20/50. You could also do the same thing by pulling out the pressure regulator valve. Again, all this assuming the oil pump was apart or the engine has been sitting a long time. That'd be a good time to check the valve to make sure it's working OK too. Good luck.

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70 Jeepster Vert
73 Bullnose
71 HC
70 Wagon
69 HC clone
86 Power Ram 383

Edited by Original70 (Sat Mar 26 2005 06:16 PM)

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67JPsTrConv
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does it have cast rockers or stamped steel 225 has cast 231 has steel. 231 oils thru the push rods and 225 oils thru block. If you used 231 head gasket on a 225 motor the oil hole is blocked off . Other than tear engine apart I would try punching hole thru head gasket. If you can not I would suppect that uyou have a 231 block with 225 top end, the early 231 75-77 were same.
John P.

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67 jeepster conv-stock, being fixed up to be daily driver
71 jeepster conv maybe restoring it

Edited by 67JPsTrConv (Sat Mar 26 2005 06:37 PM)

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jeeptchr


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yes they dis-assembled the motor except for the crank, pistons and cam.

at one point and time they primed it thru the dist with a drill and a priming rod, like a chevy. the motor has what look to be cast alum rocker arms on a steel shaft. and the pushrods are solid not hollow. the block seems to be a 231 it has 3.8 stamped on it. the head's however we just assumed they were 231 because of that. the head gaskets for both are the same aren't they? what do you mean the rockers are stamped steel? are they mounted on the same assembly as the alum. ones? also do you mean that the early 231's 75-77 were the same as a 225 on assemby and oiling? what would you use to punch thru the gasket? a steel rod of the correct diameter? how do I determine what head's I have?

as a side note we were having trouble with getting the "premium" fel-pro head gaskets to seal because the inpregnated silicone rings would run off the edge of the head or block when they went to the cheaper gaskets that didn't have the silicone impregnation everything sealed up and didn't leak on the cooling side of things.
Brad J

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Paved roads are a prime example of needless goverments spending......

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jeeptchr
stranger


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I've been giving this some thought, my head's have the oiling hole's in them. if I do have a 231 with 225 head's or at least 225 rockers, could I put in 231 pushrod's and then oil the upper end that way if I can't get the oiling holes thru the head to work?
Thanks for the help. Brad J

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Paved roads are a prime example of needless goverments spending......

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67JPsTrConv
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All 231s oiled thru push rods and had stamped steel rocker arms on hollow shafts. I don't think the cast rocker would get enough oil because they used oil pressure to force oil to the places need and don't rely on splash oiling. I'm not sure but I do not think you can change rocker assemblies. 231 blocks were not drilled with the oil passage to head, that I know of.
John P.

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67 jeepster conv-stock, being fixed up to be daily driver
71 jeepster conv maybe restoring it

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jeeptchr
stranger

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What would be the disadvantge/problems of running 225 head's on the 231 block if that is indeed what has happended here; if I get the oiling problem solved. Tommorow I'm thinking about going to buy a few pushrod's that are for a 231 and see if I'm can get oil up to the top end that way.
wouldn't it then oil every thing only backwards of the original design. If the rocker assembly's would interchange that would be better also.

I've established that the head's are from 67-74 according to the casting info on the http://www.earlycj5.com/tech/engines/225/castingNumbers.shtm
site. I couldn't find an exact match for the block but it seemed to match a 79-81 block # (two digits were off but that could have been me reading the #'s off the block) It looks like i'm in one of those pieces and parts motors someone before me put together without much research.

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Paved roads are a prime example of needless goverments spending......

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jeeptchr
stranger

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ok I found an image of the 231 rocker arms and heads's so I understand why the rocker arm's won't interchange. what are the thoughts on the oiling via pushrod's for the rockers for the 225 heads



if you've made it this far in reading this post keep in mind that this motor is assembled and running it's not oiling the top end however and that is my concern. has anyone ever tried this? if so what were the results? also is there a way to make it work or should I just part out the upper end of the motor and start over. I'd like to make it work if I could just because I've already put quite a bit of $ in it and now a little bit of time.

Thanks for your time
Brad J
jeeptchr@hotmail.com

 

If Nickmil does not respond to this post send him a Pm, he is the resident expert on yhings like this with this motor.
I can only wonder how your heads are sealing to the block as there are quite a few differences in the water pasages between the 2 different generations of blocks and heads you have. I would think that the newer style pushrods would oil ok when you changed them if you changed the rocker set up but I'm not sure how the setup would hold up in the long term!!!

 

This was just mentioned recently in a related post by Vanguard? IIRC, the 225 does not oil through the push rods but the rocker casting. (or something like that)