L46 camshaft recommendations

[Peter S.]

Re: L46 camshaft recommendations

I also recommend this cam to replace the L-79 cam, but installed with an adjustable timing set that allows it to be advanced 4 degrees to bring the IPOML to L-79 spec 110 deg. ATDC. As ground the L-46 cam IPOML is 114 ATDC.


Duke

[Duke W.]

Re: L46 camshaft recommendations

I do recommend advancing the L-46 cam four degrees if installed in a L-79 due to the shorter stroke. This brings the IPOML back to 110 deg. ATDC, which is the same as the L-79 cam.

Advancing it on the longer stroke L-46 is an option depending on your driving style/habits and the result you are looking for. It will improve low end torque a few percent while reducing top end power a few percent and reducing maximum useable revs by a few hundred.

If you really want to boost low end torque by a substantial amount, buy a 3.75" crank shaft and appropriate pistons to maintain compression in the 10-10.5 range.

Based on your statement in the original post advancing the cam 4 degrees may be best for you along with developing the most aggressive centrifugal advance curve possible without detonation, which will combine to improve low end torque as mluch as possible. Idle behavior will be unchanaged, but you should limit CR to 10.3, true maximum.

Duke

[Peter S.]

Re: L46 camshaft recommendations

I do recommend advancing the L-46 cam four degrees if installed in a L-79 due to the shorter stroke. This brings the IPOML back to 110 deg. ATDC, which is the same as the L-79 cam.

Advancing it on the longer stroke L-46 is an option depending on your driving style/habits and the result you are looking for. It will improve low end torque a few percent while reducing top end power a few percent and reducing maximum useable revs by a few hundred.

If you really want to boost low end torque by a substantial amount, buy a 3.75" crank shaft and appropriate pistons to maintain compression in the 10-10.5 range.

Based on your statement in the original post advancing the cam 4 degrees may be best for you along with developing the most aggressive centrifugal advance curve possible without detonation, which will combine to improve low end torque as mluch as possible. Idle behavior will be unchanaged, but you should limit CR to 10.3, true maximum.

Duke

[Duke W.]

Re: L46 camshaft recommendations

I think you will be better off going with the KB hypereutectic pistons with a smaller dome or even a slight effective dish such as a flattop piston with valve reliefs. That way you can used a thinner head gasket The KBs should be much less expensive and very durable for your driving conditions. Also remember that KB piston dish/dome sign convention is opposite Sealed Power, so make sure you get the sign right in the CR calculator.

And make sure whoever assembles the engine follows the KB recommended top ring gap range, which is greater than OE. Otherwise ring butting and breaking a piston is a possibility. There is nothing wrong with the pistons, contrary to all the internet chatter. The problem is the morons who assemble the engine and don't follow the top ring gap recommendations.

Dke

[Peter S.]

Re: L46 camshaft recommendations

Duke,

Motor has already been overbored and the 2304s are already in the hole! What is the concern with using a head gasket of this thickness?

Peter

[Duke W.]

Re: L46 camshaft recommendations

...not a huge concern, but I prefer less quench clearance, and port alignment may be a little off, but what's done is done.

Duke

[Peter S.]

Re: L46 camshaft recommendations

Duke, Joe and all,

I really appreciate all the help you guys have given me on this rebuild. The motor is complete save a few loose items (starter, missing motor mount) and tweaking (shorten some A.I.R. hoses, paint touch up). We will be installing it at our Chapter's tech session next weekend.

It's not 100% correct. I reused many parts that came on it, but you know what they say: if it ain't broke...

Thanks again.

Peter