AMC 258 six cylinder

[alanrockwood]

Just out of curiosity. Is the AMC 258 cubic inch straight six a good engine for marinizing? I understand it is considered one of the better straight six auto engines.

[gonzo]

No, unless you want an expensive hobby and are really qualified to re-engineer it.

[alanrockwood]

Originally Posted by gonzo

No, unless you want an expensive hobby and are really qualified to re-engineer it.

Good point.

I'm just curious though.

[CDK]

I think you are talking about the engine from an AMC Pacer.
It was notorious for the long exhaust manifold that used to break in the middle after a few years because of contraction/expansion. AMC never solved that problem, the replacement manifold also broke.

[alanrockwood]

Originally Posted by CDK

I think you are talking about the engine from an AMC Pacer.
It was notorious for the long exhaust manifold that used to break in the middle after a few years because of contraction/expansion. AMC never solved that problem, the replacement manifold also broke.

The engine was manufactured for many years, both before and after the Pacer line of carr was made, and even after AMC itself disappeared. It was a fairly popular and well regarded engine in the Jeep product line and continued to be manufactured up until relatively few years ago.

I don't know if it had the problems you noted in all its incarnations, or just in the Pacer line.

[CDK]

My experience is limited to two Pacers I owned many years ago. One used gasoline, the other one I converted to LPG; both suffered from the manifold issue (among lots of other problems as well).

[PAR]

Nothing a header wouldn't fix. The 232 AMC engine was the one you wanted, not the 258. The 232 was a solid engine, produced for a long time and I think a left over casting from Nash (could be wrong here). As far as a marine conversion, if you have one hanging out of you pocket, then use it, but there are much more common L-6 engines to choose from, making parts reasonable.

[alanrockwood]

The 232 AMC engine was introduced after the Nash era was over. It came out in 1964. Variants of this family came in a variety of displacement ratings and the family was produced until 2006.

Possibly the 242 cubic inch version may be better than the 258 cubic inch version I first mentioned. The 242 was the one produced until 2006.

The biggest member of the family was 282 cubic inches.

[alanrockwood]

If not the AMC straight six, then what are some other good straight six engines for marinizing?

[alanrockwood]

Thanks for the replies so far.

Now that I think about it, I think the topic is a better match to the DIY marinizing discussion group. Would it be possible to have the thread moved over there?

Thanks.

[Boat Design Net Moderator]

<thread moved to DIY Marinizing>