365HP engine rebuild with LT-1 cam, should I advance the cam/

[Craig F.]

I am rebuilding my 365hp motor and using the solid LT-1 cam vs the 30/30 cam and wondered if anyone has advice if this cam should be installed 3-4 degrees advanced for best power and performance or at zero. Everything else regarding the rebulid is all stock.
Thanks,
Craig

[Duke W.]

Re: 365HP engine rebuild with LT-1 cam, should I advance the cam/

No. Advancing a cam trades some top end for bottom end power - otherwise known as low end torque. The LT-1 cam provides a noticeable low end torque improvement over the 30-30. If you need more, get a milder cam. The LT-1 cam should provide about 80 percent of peak torque at about 2000. The 30-30 doesn't make 80 percent until nearly 3000. Big difference!

I hope you're replacing the spindly OE rods with Eagles SIRs or something equivalent.

And of course, head massaging and the LT-1 cam will provide useable power to about 7200, which the OE springs can handle with careful installed height setup - .090" coil bind clearance using maximum valve lift at a 1.44:1 rocker ratio.

Duke

[Craig F.]

Re: 365HP engine rebuild with LT-1 cam, should I advance the cam/

I am using your 327 build advice that you posted a while back so I am using the Eagle rods, it actually did not cost much more after you price preping the stock rods so I considered it cheep insurance as this motor should pull to around 6,200-6,500 and I am only going to do this once. The 461 heads off my motor have been street ported in the past and have good springs in them now, when I got it someone put the 302 2nd design off road cam with these so I am thinking the springs should live fine with the LT-1 cam.

[Duke W.]

Re: 365HP engine rebuild with LT-1 cam, should I advance the cam/

"Good springs" are Sealed Power VS677, which are equivalent to the 3911068 OE springs. Nothing more, nothing less. They cost about a buck a piece. If you still have the off road Z-28 cam springs, get rid of them. If you set up the VS677 as I recommend valve float starts at about 7250.

If your heads are properly massaged, it will make useable power to 7200.

Did you have them flow tested?

What is the data?

Duke

[Michael G.]

Re: 365HP engine rebuild with LT-1 cam, should I advance the cam/

"Good springs" are Sealed Power VS677, which are equivalent to the 3911068 OE springs. Nothing more, nothing less. They cost about a buck a piece. If you still have the off road Z-28 cam springs, get rid of them. If you set up the VS677 as I recommend valve float starts at about 7250.

If your heads are properly massaged, it will make useable power to 7200.

Did you have them flow tested?

What is the data?

Duke

Which aftermarket vacuum advance would you recommend for this application?

[Duke W.]

Re: 365HP engine rebuild with LT-1 cam, should I advance the cam/

The answer is in my San Diego presentation.

Duke

[Michael G.]

Re: 365HP engine rebuild with LT-1 cam, should I advance the cam/

The answer is in my San Diego presentation.

Duke

Ok Duke......since most of were'n't at SD and don't have the publication handy. Care to let us know?

[Duke W.]

Re: 365HP engine rebuild with LT-1 cam, should I advance the cam/

It's easy to find with Google. Search Duke Williams San Diego Corvette.

Duke

[Michael G.]

Re: 365HP engine rebuild with LT-1 cam, should I advance the cam/

Anyone know which aftermarket vac can seems to work best in this application with the LT-1 cam. Thanks.