[Geo71]

A stock ls3 cam is like a 204/211 117 lsa
There’s a point where torque and power will start to decrease at the low end and increase at the high end. That 225/238 cam is probably the happy middle that Brian Tooley found from extensive testing.(best all round HP/TQ for a specific RPM range) LSA plays into the idle quality higher the LSA (less over lap) the better the idle quality is. A lower LSA number brings the rpm range down but increases chop at idle. The pro’s that can spec a cam properly can get you exactly what you want if you tell them exactly what you have.

And that is with a factory efi setup. With a big single plane and carb setup takes a different cam. Mainly why I stayed away from TSP / BTR. They are more efi stuff.

My problem was not the cam, could a different one be better? Of course, every cam is the wrong one right? Haha…took the car out for a bit of a test today. The lifters made a pretty big difference it seems. Now the back tires break loose at 35, never did that before. AFR was pretty fat, will work on that and get the dragy charged up. Sucks my local track closed up.

 

[Geo71]

following this build closely, im doing a 6.0 for a 79 malibu, stg 1 prc heads, 11:8 compression, wiseco pistons, went thru 5 cam companies for suggestions, this is 300lb powerglide car, 5000 stall, 4.56 gears i settled on a pat g 243/250 .629/.615 on a 110, one other cam recommendation was close to this, other cams were in the 225/235 range, same specs given to every company, 6800- 7000 rpm shift points
wont get to the track until june, waiting on a holly terminator to finish up,,,

Using a carb? My cam is close to that, t350 /5200 stall 3.90 gears. shifting at 7200.

 

[Geo71]

I had a cam spec’d by Jones here is what he cam up with for a 398 ci with a 6500 rpm peak and a 6800 shift point. This is with TEA TFS 235 cnc heads(cathedral ports) This is the largest cam I was spec’d with the only one with this large of split intake to exhaust the rest were all 4-5 more then the intake due to the heads I/E flow percentage. The exhaust flows really well with these heads. Ramp rate are the most aggressive also.

View attachment 737308

Looks alot like mine, just a touch less exhaust duration. Will have to dig up my cam card. Judging by mine being shifted at 7200, looks like that would have been about 6800 in yours.

 

[300stw]

efi with a tbss intake and 50lb injectors for now

 

[Geo71]

So checking things over after my test drive a few weeks ago. Remembered it was 10.8 afr so I would swap some jet sizes down and give it another try...pulled the rear bowl and found this.
Yup, no rear jets. Put some in alittle smaller and hope to try it tomorrow.

 

[69-CHVL]

So checking things over after my test drive a few weeks ago. Remembered it was 10.8 afr so I would swap some jet sizes down and give it another try...pulled the rear bowl and found this.
Yup, no rear jets. Put some in alittle smaller and hope to try it tomorrow. View attachment 738681

Wow was that like that from the factory? Talk about QC (or lack of)!

 

[Geo71]

Wow was that like that from the factory? Talk about QC (or lack of)!

No I wish I could blame that on someone else, but that was all me. I had been swapping carbs last year between this 750/ 850 and 1050. Must have taken them out at some point.

Since it broke the tires loose at 35 with no rear jets and 10.8 wot afr, should be interesting to see how it is with alittle smaller jet next time.

Charging up the Dragy for another test later.

 

[Geo71]

Oh yeah the lifters made a TON of difference. As soon as you hit the gas it hits 7000 and time to shift. Finally some giddy yup!!

 

[69-CHVL]

Oh yeah the lifters made a TON of difference. As soon as you hit the gas it hits 7000 and time to shift. Finally some giddy yup!!

So the Caddy lifters are still avail? Do you have a part #? I'm running a new set of genuine LS7 lifters, seem to be working ok, little bit of noise. Still a lot quieter than my 502!

 

[Geo71]

So the Caddy lifters are still avail? Do you have a part #? I'm running a new set of genuine LS7 lifters, seem to be working ok, little bit of noise. Still a lot quieter than my 502!

Should be this part number. 88958689 GM Performance Parts. With mild cam and spring pressures the LS 7 lifters should be fine.

Mine were Summit knock off lifters. Hope to find out Friday to see if this made as much difference as it feels it did. Seems as strong as it did before hitting it with 100 shot.

 

[Geo71]

If all goes well will hit the track tomorrow. So far looking over datalogs, last year it would take 3.8 seconds to go from 4000-7200. Last nite it took 2.2 to go from 4000 to 7500. Hit the rev limiter before I knew it! Hoping that is a good sign.

 

[Geo71]

Finally got a chance to hit Summit Motorsports Park. After the winter changes and a set of 4.56 gears. It still runs 12.0’s @112. [email protected] 1.65 60’.
Made three passes:
first pass bogged at 26* timing. Shifted at 7400/ 7200
Second pass changed to bigger primary squirter to fix bog and set timing to 28*. Shifted at 7200/7200
Third pass back to 26* and shifted 7400 /7200

Only upside so far to the gear change is better reaction times. Still a good bracket car.

Time to start spraying it next time out.

 

[Geo71]

Took the car to Dragway 42. A friend took a video of it. Changed to 4.56 gears, Firecore 50 coils and swapped the Cheater plate for a Bigshot plate. 150hp jetting to start, pulling 5* and ramping it in starting 20% for .5 sec. Needs a bigger carb and some intake porting, datalogs are showing a restriction. Ran [email protected] 1.54 60’ From a [email protected] 1.65 60’ previous pass On motor. Plugs looked good.

shifting at 7200 converter is falling back to 6300 on the shift, flashes to 5500 and crossed the line on the rev limiter at 7500. Gonna have to set it alittle higher Im a thinkin.

I think I can hit 10.50’s pulling 4* and turning the ramp off, well if the tires hold it.

after talking with three different cam companies and my converter company, the consensus is the cam isn’t too big and to spray it.

 

[Geo71]

Went to Summit Motorsports park for their last tnt…for the heck of it cranked up the timing from 26* to 32* and ran [email protected] Then went to 33* and went [email protected] Should have tried that before. Then sprayed it pulling 4* from 32*. AFR was way lean with the added timing so short shifted at 7000, crossed the line at 7580…[email protected] Can’t wait to get the tune figured out with the added timing and see what it runs.