375-396 Stocker valve springs?

[Frank Bialas]

Originally Posted by SS Engine Guy

Cast crank/ check each year. Anything that wasn't there the year before when checked toss it. Normally they will last 4 seasons. Make sure proper fillets are ground into the rod journals and the bearings are preped for that. 2 bolt block/ no problem. If not aftermarket block go with the thickest sonic test block and prep it with filler. The old 66' blocks were really thick. ATI or Fluidamper. Some overbalance at powerband range. Good pistons and pins. Carefull attention to detail on balance and general prep. Get someone who knows what they are looking for if using 3/8 rods and get rid of the parting line in order to mag properly. Use the best rod bolts and torque them at least 3 times during machine work and then stretch them to manufactuers spec. At next freshen up any bolts that the freestanding length is .001 or greater than in assembly log, toss them.

8200?....mine go thru the traps at that ,sometimes more and peak hp is up at around 7600 - 7800. (Peak hp is only a number to campare, peak torque is what is hard to accomplish). BBC intake ports are adequate for that number. The exhaust is the choke but with a well designed set of headers they will help that out if they scavenge well. (in the 1500-2000 dollar range for a header that works) Bullet Cams can help with some of the exhaust deficiencys. Get someone who understands the importance of a valve job to do the heads. With the new valve seat rule there is extra flow there too.

I understand the concern over piston/rod weight. Crank is rotating weight not reciprocating. Think of the weight of a 540 to 750 inch engine even with aluminum rods. Unless the rods are cyrogenic deep cycle they will weigh the same or sometimes more than a 7/16 chev. rod. Nitrous cars will usually use a heavier piston deck to be stronger in detonation situations. The biggest concern on the heavy rod/piston deal is the wrist pin on the intake stroke, when the piston stops at TDC and is pulled from a complete stop downward. That is why a good pin is necessary and monitoring them is critical.

You are correct. If you don't absolutely control the valve action with the proper spring you will run into clearance problems and beat the lifter into submission. I would tend to like a little more than not enough from a power and reliablility standpoint.

Just asking??? At what RPM does the RAT puke out peak torque???

[Jim Hanig]

Originally Posted by SS Engine Guy

Why not?

ss/guy
Stocker, that is still making power at 8200 not a chance.to days world a real good one is done at 7000 at 7200 there down10 to 15 at 8200 maybe 40. So why would you go there?. Jim Hanig.

[MAURICE BLENDHEIM]

Originally Posted by SS Engine Guy

Cast crank/ check each year. Anything that wasn't there the year before when checked toss it. Normally they will last 4 seasons. Make sure proper fillets are ground into the rod journals and the bearings are preped for that. 2 bolt block/ no problem. If not aftermarket block go with the thickest sonic test block and prep it with filler. The old 66' blocks were really thick. ATI or Fluidamper. Some overbalance at powerband range. Good pistons and pins. Carefull attention to detail on balance and general prep. Get someone who knows what they are looking for if using 3/8 rods and get rid of the parting line in order to mag properly. Use the best rod bolts and torque them at least 3 times during machine work and then stretch them to manufactuers spec. At next freshen up any bolts that the freestanding length is .001 or greater than in assembly log, toss them.

8200?....mine go thru the traps at that ,sometimes more and peak hp is up at around 7600 - 7800. (Peak hp is only a number to campare, peak torque is what is hard to accomplish). BBC intake ports are adequate for that number. The exhaust is the choke but with a well designed set of headers they will help that out if they scavenge well. (in the 1500-2000 dollar range for a header that works) Bullet Cams can help with some of the exhaust deficiencys. Get someone who understands the importance of a valve job to do the heads. With the new valve seat rule there is extra flow there too.

I understand the concern over piston/rod weight. Crank is rotating weight not reciprocating. Think of the weight of a 540 to 750 inch engine even with aluminum rods. Unless the rods are cyrogenic deep cycle they will weigh the same or sometimes more than a 7/16 chev. rod. Nitrous cars will usually use a heavier piston deck to be stronger in detonation situations. The biggest concern on the heavy rod/piston deal is the wrist pin on the intake stroke, when the piston stops at TDC and is pulled from a complete stop downward. That is why a good pin is necessary and monitoring them is critical.

You are correct. If you don't absolutely control the valve action with the proper spring you will run into clearance problems and beat the lifter into submission. I would tend to like a little more than not enough from a power and reliablility standpoint.

Alan & SS/EG...Your right the trap RPM would be@ 8200+ with the gearing required. That RPM would not be sustained. We have a cast crank, "272" 4 bolt block Hardblock filled, aluminum ATI 2-ring balancer, CP pistons and pins MANLEY rods, BULLET and COMP cams STAHL headers and the most current valves (1968- 375) and seat work (Nashville influenced). We feel we ours will be "a good one". Combined with the Youngblood clutch and G-Force transmission in a 1968 Camaro should be quite an experience. I guess we are far from being a "dime rocket?". Peak torque is what has our attention, there is only so much you can do. Thank you guys again for your interesting input.

[killintime6968]

Spin it till it breaks then build a new one and back it down 200rpm. Oops i think i've done that a couple of times. Maurice , your stocker project sounds pretty good especially being a stick car. Hows the nova project coming. You also need to kick Rolfs butt into gear.

[SS Engine Guy]

Originally Posted by Frank Bialas

Just asking??? At what RPM does the RAT puke out peak torque???

Frank, peak torque at 1000 - 1200 under peak hp.

Maurice, sounds like you have a nice piece going together and you can't go wrong with the "Nashville" influence. No, not dime rocket material but fun! And the clutch combo will be really nice!

Jim, I don't know what your shift points are but if you aren't making power out of a solid lifter, holley carbed, decent intake, hi comp motor any higher than 7000 I don't know what to tell you.

[Dinsdale]

Originally Posted by MAURICE BLENDHEIM

Jim... Our pockets are standard length, just resourceful. We are prepared to spin it to 8200 if that's what it takes.

You must have deep pockets if you can afford to "do lunch" every Saturday at Wendys.

[MAURICE BLENDHEIM]

Originally Posted by killintime6968

Spin it till it breaks then build a new one and back it down 200rpm. Oops i think i've done that a couple of times. Maurice , your stocker project sounds pretty good especially being a stick car. Hows the nova project coming. You also need to kick Rolfs butt into gear.

Bruce... The Camaro stocker is Gordon Merkley's D/S 302 car, will be a 375 396 in the spring. My Nova is a 1970 SS/EA 375 402 , doing electrical and interior now . I've spent more time than I had originally planned on this project, it is completely new front to back. We have a considerable amount of time on this engine combination since the Old Blue 66 Chevelle SS/F car Gord had with its iron head 375. We've pulled the engine on Rolf's car and I have another similar combination ready for it. Do you still have the old Checkmate car?

[Jim Hanig]

Originally Posted by SS Engine Guy

Frank, peak torque at 1000 - 1200 under peak hp.

Maurice, sounds like you have a nice piece going together and you can't go wrong with the "Nashville" influence. No, not dime rocket material but fun! And the clutch combo will be really nice!

Jim, I don't know what your shift points are but if you aren't making power out of a solid lifter, holley carbed, decent intake, hi comp motor any higher than 7000 I don't know what to tell you.

I tell you what you show me a stocker 375 that makes power above 7000 -7100 . Jim

[killintime6968]

Maurice, yes we still have the Checkmate camaro. Slowly been working on it. Repainted the underside after repairing old damage from a few driveshaft explosions and then rewired the car this summer. I am quite surprised that it never had any shorts or caught fire with the old wiring. Hopefully we will get the car finished this winter but that was goal last winter. So we will see what happens. We hope too see you, Rolf, Gord and the rest of the gang next spring at the Mission points meet or even Ashcroft.

[Pedigo Perf]

Originally Posted by Jim Hanig

I tell you what you show me a stocker 375 that makes power above 7000 -7100 . Jim

How about a pair of them.