336/343 RW #'s...

I had hoped for more, but I suppose at the end of that day it IS a small cam.

It only wants 24 degrees of total timing, pump 93 octane, 160 degree thermostat. It's pretty much full bolt ons - TBSS intake, 92mm TB, headers, exhaust. Junkyard shortblock of unknown miles, had crosshatch in the cylinders, cam bearings are pristine, excellent oil pressure. (Stock oil pump) Heads are also from the junk yard. I hand-lapped the valves when I did the springs and seals.

My previous set up had a low mile LQ4 long block, EPS 214/220 .606/.604 112+2, stock thermostat, and 87 octane. Same intake and exhaust system as it has now. I basically changed long blocks after a lifter failure. It made 327/369 - same dyno and tuner. Around 19-20 degrees total timing.

That said, kind of bothered by the current setup. I feel like it should have done better by at least 10-15 on both HP and TQ.

For reference the TSP cam is 214/222 .550/.550 108+2

 

are you going for more power?
Those cams are extremely close to the same size Your only real difference is 87vs93 octane?

214/220 .606/.604 112+2
214/222 .550/.550 108+2

 

Besides Springs, did you do anything to the heads?

 

No, I lapped the valves in by hand. Then changed the springs and seals. Otherwise, untouched.

 

The cylinder heads and cam are the only differences other than the fuel type. I realize the cams are close in size on paper, but expected the 1 point increase in compression and better fuel would be worth more than 9 RWHP, and not lose torque.

Basically, I daily this truck currently. After the lifter failure in the other engine, I needed something quick to get it back up and running. I had these parts "in stock", so I slammed it together and put it in the truck.

 

I bet you would see some improvement by going to a 2 inch intake and blending the valve job into the bowl.

 

you also gotta consider that the new cam has 9� more overlap (+2� vs -7�), so look into how much that changes the dynamic compression ratio after your .9 static bump. that'll also tell you if 93 really buys you any benefit over 87.

as also mentioned above, the LM7 heads don't breathe as good on the top end with the smaller valves & runners... not saying they're bad heads, though.

 

WHy you install 160 degree thermostat ? That's not going to help a daily driver last.
.
. If your dyno time is cheap, try same tune running 87 octane: You might pick up more than your 9 missing horses..... Yes, I am serious.

 

Here may be why. I am personally tired of feeling the sluggishness when its over 85deg outside and will be putting in an 160 this spring. Not so much in the winter though.

Brian

 

but do you have a much-better cooling stack that dissipates enough heat to hold the water temp below 190�? if not, then it's a futile effort and the thermostat will just run longer in the open position while maintaining the same temperature.