What does everyone think, just had my computer sent out to madwolf and intake sent out to lloyd E. still have a little time to decide. Stock bottom end, ported heads, ss 1.6 rr, gm 847 and other mods in sig with 3:73's. Should I noticed people shift anywhere from 6500-6800 with the 847. How much track time would it be worth for me to crank over 6500?

 

You really need a dyno sheet to figure out your shift points. But as far as a guess, people on stock heads with the 847 cam are shifting at your stated RPMs so I would bet it would be closer to 6800-7000rpm shifts, as the ported heads are going to bump up your top end potential.

 

Never had the 847 cam but its brother the 306 and w/ good valve springs I was tapping 7200rpms, and it pulled every bit of it on the old setup 350. Not saying you have to shift that high, but I did because when I shifted to the next gear, it put right in the rpm I wanted to be in.
My new setup doesnt pull that high. 6500rpms is all I go on the new setup.

 

with this cam the higher it revs the harder it pulls ive only gone to bout 6700 but it pulled from 3000 on up and didnt stop i say go as high as you feel safe goin

 

ok so so far 40% say 6500 and 40% say 6800, one person says 6600, I've told madwolf 6700 and got no votes for that?? Does anyone feel that 6800 rpms on a stock bottom end with 71,000 miles on it will hold up to 6800 rpm shifts for at least a couple summers?? I'm kind of confused really that almost half would vote 6500 and the other half at 6800. Does anyone have anything close to this setup with stock bottom end What do you shift at and what do you turn throught the quarter, and how long have you been doing it? thanks,

 

Stock bottom end with those miles...I would say you will need luck at those rpms to keep from spinning a bearing (unless you have exceptional oil pressure). Some people have luck, though.

As TQdrivenws6 said, dyno results are what you need to figure shift points. You need to know where your best power is.

 

ok how many people do have luck with cranking 6500 or more on the stock bottom end? thanks,

 

I spin my cc306 to 6550 with stock heads, so I would think that with the ported heads you could/should go up to 6700 or so.

 

how many miles does your shortblock have on it and how long have you been taking it to 6550? Nice times cam only! I hope I can at least match guys like you and altjar that have a cam only.

 

I've spun my 233/239 to 6700-6800 at the track. This yielded the best times/MPH, however, shifting it at around 6500ish was only a couple tenths lower and like 0.6 MPH less. I have under 60K on my bottom end.

 

164k miles on stock bottom end w/ 306 touching 7200 on the shift.
The motor was not blown when I took it out. I only took it out b/c I picked up a Stroker kit cheap and put it in. The bearings, pistons, rings etc... Still looked good. Cant really say Im lucky, my sh** breaks all the time.

 

I say set the limit at 7000. My stock head 847 car peaks below 6000, but it runs the best shifting around 6400. With heads, I'd hope it would peak at least at 6200, so you could shift around 6800 and have 200 left for margin. As far as the bearing issue goes, its really hit or miss. Happened to me once with a CC305 shifting at 6000. So far (knock on wood) this used motor with 847 has been alright, but I did put in a new oil pump with white spring. I'd recommend the same to you. Its cheap insurance.

 

i say 6600. on a stock headed car

 

The rule of thumb for years has been 10% over your peak HP rpm-ie.peak at 6500=7150 shift point.

 

wow 164,000 and cranking over 7000 thats pretty awesome. Looks like theres a few cranking the rpms with the stock bottom end including madwolf whos about to tune my computer, but like everyone says the guys with stock heads may be ok shifting a little earlier but with my heads being ported and flowing 265/200 then I'll probably gain shifting at 6700 as opposed to 6500, I hope then hopefully I'll find a good place to get it dyno'ed then maybe I can get it dialed in just right by having madwolf retune and reset shift points if needed. This poll things pretty cool but it seems like all the shift points I've listed are falling pretty even with you guys. thanks,