I am installing Andrews TW37b cams with CP M5011 Pistons on my 2000 FXDL 88ci. I am switch to a Cometic MLS head gasket to help control the higher compression. I would like to stick with the stock push rods. The base circle on my stock cam and the Andrews cam are the same. Can I put the .0045 MLS head gasket in and be ok or should I play it safe and install the .0051 MLS gasket?

Thanks for reading and let get some dry weather!

 

The .045" gasket will be OK and you can retain the OEM pushrods. Bigger issue with those pistons is that you should have the heads prepped and compression releases installed. Your battery and starter will appreciate it.

10.2 static CR and near 200psi CCP is a bit much for those cams. Be prepared to run premium fuel and listen for detonation when summer heat comes along. A .030" head gasket would help mitigate against detonation but would bump comression up to about 10.5 which, IMHO, is OTT for those cams and the motor would be a ping monster.

EFI or carbureted?

 

It is carbureted and all I have ever ran in the bike is premium. Not a fan of putting ethonal through her.

How did you come up with 10.2? I get 9.6 when I do the math.

 

My bad. I plugged the 9.9cc dome volume for that piston into my compression caculator and it spit out 10.2; however, I forgot to change the bore to 3.750"; I had it set at 3.875" for the last calc I did; you are OK at 9.6. As a matter of fact, you could probably go to the .030" Cometic MLS head gasket and bump the static CR up to 9.8 to really make that 37 bite. This assumes your deck height is typical of the early models and pistons are down in the hole .003"-005". If deck height is 0.00", a .040" head gasket will work.

Rejet and you will be fine. You might consider an aftermarket programmable ignition like the DTT unit so you can play with timing.

You are fortunate to be able to run fuel without ethanol, dang near impossible to find in my neck of the woods. You should be happy with that setup; you need the compression to get the most out of the 37 in an 88" motor.

 

All Kwik Trips in Wi have ethanol free premium. Some other gas stations are doing the same. Where are you located?

I measured the deck height last night and it is at .003. Stock is 190 main jet and 45 skow speed. I'm going with a 200 and 50 and already put a different needle in.

 

I would not run the .045" head gasket; either the .040" or the .030" and with real premium fuel available, the .030" would be my choice but either is fine. I like to keep squish below .040".

I think I would start with a 48; the needle will be the key. I live in south Texas where you would think you could find ethanol free gas. My 107" hipo motor will run fine on 87 and while I haven't had any issues with ethanol fuel, I would like to find some real fuel.

I run a CV44 on my all bore 107" with a Yost kit and run a 210 main and 48 slow, their emulsion tube and adjustable needle; works well and very tunable. Drilling the vacuum port and installing a lighter spring improves throttle response.

 

9.8 cr is a good squeeze for those.
We prefer a good adj pushrod to load the lifter properly (.140-.150") to maintain quiet engine operation at full operating temps.
Scott