Head exchange question

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Bughappy
Posts: 49
Joined: Wed Apr 15, 2015 7:59 am

Head exchange question

Post by Bughappy »

Question about changing heads on LM motor. I have been working on a '65 monza coupe I bought a couple of years ago... it is a 110 W/auto trans car that once had AC.. (still looking for some parts there) Body & Paint nearly done, interior as well (dash still needs work but headliner, carpets, seats and hand built console done).. so here is my question... Can I replace existing 110 heads with 140 heads I recently bought? I understand linkage, carbs & exhaust will have to be changed... is there more I will have to do? (current 110 motor runs well, good compression in all 6 cyls & 140 heads are in machine shop being rebuilt) Since I'm not a mechanic I thought I better ask the experts before I tear into a running car... Thanks in advance for any help
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terribleted
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Re: Head exchange question

Post by terribleted »

The engine will run overall OK. It would be best to have a 140HP distributor for the best advance curve for the 140. Other differences between the 110 and the 140 are more minor things such as hardened crankshaft (not a big issue) and side sheet metal pieces that will accommodate the 2 extra carb pads (find correct parts or snip out the metal you need to on the 110 parts to fit. It would be best to have a 12 plate oil cooler if it isn't that already.

That said the combination of 140HP motor and an automatic transmission is not ideal. The extra power of the 140 just doesn't do much through the automatic. The factory 140 automatic cars use a retarded crankshaft to help the setup function better. If it was me I would stick with the 110 on a powerglide. To go 140 you add a lot of complexity (extra carbs , linkage etc) for not that much gain in usable performance, and higher operating temps, not to mention the 140 heads propensity to drop intake valve seats. I would keep the 140 heads until I could put them in a 4 speed car where the extra power can be fully utilized.
Corvair guy since 1982. I have personally restored at least 20 Vairs, many of them restored ground up.
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Located in Snellville, Georgia
Bughappy
Posts: 49
Joined: Wed Apr 15, 2015 7:59 am

Re: Head exchange question

Post by Bughappy »

Many thanks... that was the info I wanted... Since I got the 140 heads with a NON-running 140 motor I should have most all the extra parts.... However the Head swap was only to look a bit better at local cruse-ins & future plans are to give the car to my grandson in a couple years for him to sell or use for first year at university I guess I'll stick with the 110 motor & list the 140 heads here some time.... Thanks Again
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