CRAP! CONFUSED- I was told that redoing m20 head with 275k may cause problems

[clydesdale]

I am not sure if I should take the head off on this car or not. I eat a spark plug or two every 10-15k miles. I have a little oil in the coolant. The car drives fine. I have had the spark plug issue for the past 30-40k miles.
I called Turner Motorsports who referred me to a specialist out west. He thought that rebuilding the head will likely cause increased oil consumption and blow by. He thought with 275k miles, the new tight head would likely create compression that the bottom could not handle and the car would likely eat oil and blow smoke. He says that he sees that happen 75% of the time when they redo a head with this many miles on the bottom end. I am beginning to think that I should just slap the motor back together and change the spark plug every 10k miles or so and start looking for another motor. Thoughts? Thanks guys, I am really confused on where to go with this motor. Not to mention the fact that I have yet to find a local builder in NY.

[blacksport325]

Didn't you just have a thread about whether or not you should do the HG? If it is true that you will have the lower end with more strain on it and it could cause problems, then I guess your stuck...it really all depends on how much money and time you want to put into this car, rebuilding seals on the bottom end is an option if you want to go all-in. At that point your better off sourcing a low mileage M20, or M50

[redsubdivisions]

Well, if that's the case, look for another motor. 275K is impressive for an 80's car, let alone a motor that has been in production before that particular model was even produced. I would source one, rebuild it to get you some experience, and then go from there. It will cost time and money, but that's what investments are.

[clydesdale]

Yep, I had a thread about whether or not to do the head gasket. But, if you look at it, we never really addressed if the mileage made a difference. Now, I am being told by a builder that comes recommended by turner motor sports, that I may be avoiding the inevitable and need a full rebuild. He was sort of thinking I should just put in new plugs and let it run.
I also called Memphis motor werks, who came recommended by Mr. M car in NJ, and MMW said it would possibly be a problem but really couldn't say one way or the other. They agree a full rebuild would be better, but could not say if doing the head was a bad idea. So, I have not really determined if it is a good idea with 275k miles.

[jlevie]

I'd have the head decked, valves ground (or replaced as appropriate), install new seals and probably replace the cam or have it ground back to spec. On a 275k engine there might, or might not, be a significant increase in oil consumption. But if there is, you have a fresh head that could used on a lower mileage replacement block.

[StereoInstaller1]

Or, find a 120K motor, drop it in after a quick re-seal and throw yours away.

Or, rebuild it if you want to.

[clydesdale]

Bingo!, I am looking for a low mileage m20 in a butt ugly ass car that no one wants.

[clydesdale]

Well, I finally spoke with a LOCAL builder who specializes in heads for BMW. He services a few of the dealerships and a couple of the well know independent shops. He says not to do it and that it will likely consume oil and have increased blowby. He said that all on his own, I never mentioned that I got the same advice from the shop out in Missouri. So, I feel like I have enough advice now to make an informed decision and I have started to look for another motor. I will have a couple of posts on m20 compatibility over the years and other motor options. Thanks everyone for their help. I shall slap the ol' stede together and whip her for a little longer.

[be34st]

M50 Swap.

[bmwstephen]

Well, I finally spoke with a LOCAL builder who specializes in heads for BMW. He services a few of the dealerships and a couple of the well know independent shops. He says not to do it and that it will likely consume oil and have increased blowby. He said that all on his own, I never mentioned that I got the same advice from the shop out in Missouri. So, I feel like I have enough advice now to make an informed decision and I have started to look for another motor. I will have a couple of posts on m20 compatibility over the years and other motor options. Thanks everyone for their help. I shall slap the ol' stede together and whip her for a little longer.

I've machined my head at 200k miles and no problems so far. I think it depends on how the engine was treated overall. I was fortunate to have a thick service receipt of all 3 owners - all whom baby the car (what choice do they have when you drive an autotragic).

[clydesdale]

M50 Swap.

It is funny you mention this. I had dreams of and s50b32 swap, but that may too exotic. I want to keep the easy serviceability and fairly low cost of the m20. The s52 swap would be cheaper and apparently is well documented. But it is still an "M" motor and maybe I should steer clear for cost reasons. So that got me to thinking about my wife's 330i and the motor that is in that car. But, I am not sure how simple of a swap that is.
I started looking on craigslist and I saw a car with a m50 swap. Are these motors cheap and abundant? Why do so many do this swap? Is it much easier than the s52? What is the appeal? Is it just a good solid reliable motor? Thanks

[bmwstephen]

I've considered an m50 swap many times over and even rode in an m50 swap car. while personally to me it does make the e30 powerful, i feel that the chassis wasn't designed for it.

looking pass the swap itself, I notice people tackling never ending additional items such as electrical, suspension, steering rack, accessories, mounting points, cooling systems. just to make the car run right. In most cases, I've seen people sell the entire care shortly after the swap for reasons I can't imagine given how much time, money, and effort spent on it. All in all, to me that tells a lot about the enormous responsibility going into a swap car. You are quick to point out that, only you or people who are familiar with the swap, would be able to service it. I can imagine people taking it to a regular mechanic for a simple oil change get confused at what is in the engine bay.

[netcsk]

I put a rebuilt head on a 232k mile bottom end over 4 years ago. I'm now at 270k miles. I consume no oil nor do I leak a drop. I agree with Stephen above, it begins what you're starting with.