Newbie engine question

[phil359]

I got a 71 240 with the original engine in it, hooked up to a newer 5-spd tranny. Original SU round top carbs.

I'd like to build a new motor for it, for the purposes of cruising on sunny week-end road trips. I'd like to keep it very simple, and dependable such as it is now... No complicated fuel-injection or turbo setup, or such.

I've been thinking about a stroker motor, but after reading this article http://www.geocities.com/row4navy/engine.html on a 3.0 stoker it appears that going that route might get pretty pricey to do it correctly.

Does anyone have any suggestions on what a good motor build for about 2-3k, with good low-end torque for crusing around would be??

Thanks

[AxtellZ]

I'd think you could do a complete rebuild of the engine you have for that much.. Or get a 280 block & do the same.

A ZX non-turbo block (F54?), flat top pistons, use your original head and carbs- you should get all you want out of that combo, i would think.

HTH, Jeremiah

[240ZX]

Phil359,

You may want to give Rebello Racing, in NorCal, a call regarding your needs. They have a web site as well. Dave Rebello indicated to me a few months ago that for around $6k he will build you a 285 HP 3.0 including their modified SU's/maniflods. Just a thought!!!

[phil359]

240zx...

Thanks for the tip in the 3.0 stroker article the author did mention Rebello as a possible source for machine shop work, And I have heard of them and the great quality type work they do...

But along with the high quality comes associated cost for such work... Unfortunetly I can't justify spending that type of money for my hobby

But thanks

[240ZX]

Come on now phil359,

There is a saying my friends and I use quite often....."The more you spend the more fun you have". Just kidding :classic: Rebello has other options for less $$$ too!

[MikeW]

Originally posted by phil359

I got a 71 240 with the original engine in it, hooked up to a newer 5-spd tranny. Original SU round top carbs.

I'd like to build a new motor for it, for the purposes of cruising on sunny week-end road trips.

Is the current original engine in good shape and producing the expected stock output? In other words that may be all you need for fun cruising on a weekend road trip. On the other hand, if your requirements really are 200+ HP then forget everything I just said ...

[phil359]

Hey MikeW

I'm not sure if the engine is putting out the expected output...

I know it's not burning any great amount of oil, meaning I'm not putting in a qt. of oil every 500 miles :cross-eye

I'm not getting any big puff of blue smoke when I start it up... so I think the engine is in pretty respectable shape for being 30+ yrs old. I think it's only got about 130k on it also.

I guess I should probably do a compression check on it for base reference before I do anything... I guess I'd just like to get a little more git-up and go out of it

[2ManyZs]

You ought to do a compression and a leakdown test both, just the compression test won't tell you the whole story on the engine. If it tests out in fair shape, go find an F54 block out of a 280ZX non turbo, and rebuild it while still being able to drive and enjoy the car. Look for one with a P79 head, as you'll get the flat top pistons in the F54.

You either have the early, more desirable E-88 head on your 71, or perhaps you are lucky and have an E-31 (depends on what a PO might have done with it). Either way it will work well with the F54 especially if you change to the larger 280 valves, and the result will be 25+hp if you don't do any other mods. Then you will have a much better base to build up the engine than by using the stock L-24. Building it a piece at a time will save you money in the long run, and you'll be able to enjoy the car instead of look at it sitting in the driveway without an engine until you get the new engine put together.

[MikeW]

Originally posted by phil359

I guess I should probably do a compression check on it for base reference before I do anything... I guess I'd just like to get a little more git-up and go out of it

2ManyZs has good advice. Find out what shape it is in right now. It may seem sluggish for any number of reasons that are possibly inexpensive to fix (timing, plugs, valves, carbs, etc.). You may be able to end up with something good enough for a little fun without a big cash outlay. As he said you could later build up a higher performance engine on the side while you've still got a car that's driveable.

[phil359]

E31 head, and E31 block....

I'll probably take 2ManyZs advice and do the leak down, and Compression test and compare them up to factory specs, and build off of a F54 block.

Also 2ManyZ is the E88 head more desirable than the E31??? or is it the other way around??

I didn't know the orginal owner of the Z, but I did know the second, and third owners... they were brothers, and the big brother handed it down to his little brother... my high school buddy....

He ended up getting married, and had a few too many house projects going, and ended up selling me the Z a few years back... and I've just been slowly replacing, and referbishing parts along the way.... gawd it like I'm replacing one thing or another on this car

Thanks to everyone for your suggestions, and keep-em coming if you have any

[2ManyZs]

The E-31 is the more desirable, with the early E-88 a close second. The E-31 has a slightly smaller combustion chamber and a little better chamber shape.

With that on an F-54 block with flat tops, with larger 280 valves, would make an excellent street motor. Especially if you upgraded the cam a bit with headers and the other usual mods.

Your car sounds like my 71, I didn't know the original owner or his son he passed it on to, but the next two owners were also brothers....

[phil359]

Hey 2ManyZs

I've been searching around on the net about the E31/F54 head, block combo... and One concern that was brought up was the high compression ratio that this combination would have...

At this point I think I can safely assume that the head has never been milled, at least not as long as I've know the car. If that is the case from what I've read thus far an E31/F54 combination will give a compression ratio of around 11:1:paranoid:

I don't think that going to be very drivable on today's low octane gas, unless I use octane booster... any suggestion or recommenadtions

Thanks for you help and input :classic: