Topic: 18 hp model 42

[nothingtogain244]

I have recently picked up a 18 hp opposed twin that is a model 42 and i was wondering how these engines hold up. I havent really heard to much about them. How many RPM's can they handle stock. And also, is there any aftermarket high performance parts i can find for this motor? Thanks for any info.

[tory]

From what I understand the secret to holding them together is to keep the rpm's low.They are a good low end torque moter but do not hold up well under high revs.Loosining up the moter to high specs seems to help also(especially the top rod)Unfortinitly I dont think there is to much availible aftermarket for them.you have to get creative.TB

[speeddemon0308]

i had a 14 opposed twin ( same thing pretty much...) and i had it revin to about 5500 rpm i know that they can take that much but not for mabey over 5-10 seconds......  and they do have alot of bottom end torque

[nothingtogain244]

thanks. i was wondering what parts go bad on them at high RPM's so i can have them made for me. (i know a machinest. Good people to know) any input would be much apretiated. And also, What do you mean by "losseing the motor up to high specs?

[George Herrin]

Rods are the weak links

[tory]

If you hone or loosen the rod journals and cylinder bore to high tolerance,when they swell under high temp. you well have less chance of it setting up and breaking the rods.On a tight moter you can almost feel it bind as it heats up.If you know a good machinist,I would check into making stronger rods,but you may need to be concerned about balence.Maybe not with a 2 cylinder.Also make shur the oiling holes are there and maybe find a way to help lube the upper rod better.That seems to be the first one to go.hope this helps.TB