[Cammer-6]

you can include offset ground
details details details
stroke,rod length,piston height and type,crank type,balancer and flywheel

[Cammer-6]

so no one has any knowledge or experience at this?

[camerjeff]

Gary I sold my 301 Stroker a couple of years ago, and most of the paperwork went with the new owner.

Mne did not se any offset grinding on the GMC 292 crank, I used a fluid Dampner for a SBC, had to grind the rear face of the crank to take the OHC-6 flywheel, used eagle forged H beam rods for a Toyota Supra, with the big end shaved to fit the 292 crank. Custom Ross Pistons to fit the rods, 0.030 overbore of my best 250 block. Modified the 1bbl head spring pockets for LS beehive springs.

[Cammer-6]

Originally Posted by camerjeff

Gary I sold my 301 Stroker a couple of years ago, and most of the paperwork went with the new owner.

Mne did not se any offset grinding on the GMC 292 crank, I used a fluid Dampner for a SBC, had to grind the rear face of the crank to take the OHC-6 flywheel, used eagle forged H beam rods for a Toyota Supra, with the big end shaved to fit the 292 crank. Custom Ross Pistons to fit the rods, 0.030 overbore of my best 250 block. Modified the 1bbl head spring pockets for LS beehive springs.

I forgot about that one
wish I would have known it was for sale.
Im also thinking 68-9 1 bbl head and 66-7 4bbl valves along with spacers under lash adjusters,I have a few reground performance cams to use.
What crank did you use? cast or forged? full counterweight?
piston weight and comp height?rods length?

block and crank clearance?

[GTO JONES]

571 cu in Pump gas, MR-1 block, 4.75 Ohio crank, Eagle 6.7 rods, Ross pistons, Modified E heads 10.84 comp. , Lunati Hyd roller cam, Super Sniper EFI 8 injectors.

[einstein]

Originally Posted by GTO JONES

571 cu in Pump gas, MR-1 block, 4.75 Ohio crank, Eagle 6.7 rods, Ross pistons, Modified E heads 10.84 comp. , Lunati Hyd roller cam, Super Sniper EFI 8 injectors.

How'd you join 2 OHC6 blocks together to make it a V-12?

[GTO JONES]

Originally Posted by einstein

How'd you join 2 OHC6 blocks together to make it a V-12?

Let me know LOL.

[Cammer-6]

I did a quick search online and found a 301 claiming it was dynoed at 370/390 hp/tq
but the owner must have been posting it on Facebook which Im not connected to.
If anyone has details of this build I would like to hear more.

[sprintbird]

Originally Posted by Cammer-6

I did a quick search online and found a 301 claiming it was dynoed at 370/390 hp/tq
but the owner must have been posting it on Facebook which Im not connected to.
If anyone has details of this build I would like to hear more.

Gary, that is the highest HP NA OHC 6 build that I am aware of. Brent H who was half of Primatech built it. The only details I have is it is an all out 301 , massive head port work, solid adjustable lash adjusters, huge cam, Primatech header and side draft Webbers. Probably has a ton of money in it. My “guess” is close to 15K. You need to join FB and look us up. Overhead Cammers Chapter Forum.

[Cammer-6]

I used to stay in touch with Brent,but in the last 10 yrs or so have been focused on caring for parents.
Im not looking to build a non streetable stroker,just something with more grunt that appears stock.
I wish there was a forum for OHC-6 vs using FaceBook,as Im not a fan.
Oh wait there is...this forum. I gave up on YuKu when it crashed and we lost so much valuable info.
Had we only known to have it all backed up.

[camerjeff]

Gary, the Toyota rods I used were just under 6", 5.984" if I remember correctly, My street 301 dynoyed at 294HP at 5200 RPM, ( hit a wall at around 5800 RPM, just not enough cam to feed the cylinders with the stock head even with porting and bigger valves) and a massive 428 ft lbs at 2200 rpm. It used to pull the front wheels about 4" off the ground on a good launch with slicks.

It was a very good street engine, but the loss in higher rpm limited in the 1/4 mile.

And the 292 crank counter weights were cut down, balancing was done by drilling and adding heavy metals to the cut down counter wights. The block was also clearanced, and the oil fill tup probably should have been run outside the pan. Instead I lengthened it ran it below the oil pan bolts on the passenger side, and welded in a bulge on entire length of the oil pan to clear the tube. Ran a stock but ported intake manifold, the largest long tube clifford headers I had on hand, and a custom HEI Distributor. Along with the T-5 Transmission, and the 4.11 rear gears it was a very streetable combo.

I just kinda lost interest in it when the guy who owned the 5.0 Mustang it was built to suddenly passed away. Took alot of fun out of it. And when I purchased the LS2 Powered Solstice, I just did not drive it anymore. Didn't see myself owning another cammer until the California Sprint FB popped up a couple of years ago. This one will stay mostly stock.

[Cammer-6]

Originally Posted by camerjeff

Gary, the Toyota rods I used were just under 6", 5.984" if I remember correctly, My street 301 dynoyed at 294HP at 5200 RPM, ( hit a wall at around 5800 RPM, just not enough cam to feed the cylinders with the stock head even with porting and bigger valves) and a massive 428 ft lbs at 2200 rpm. It used to pull the front wheels about 4" off the ground on a good launch with slicks.

It was a very good street engine, but the loss in higher rpm limited in the 1/4 mile.

And the 292 crank counter weights were cut down, balancing was done by drilling and adding heavy metals to the cut down counter wights. The block was also clearanced, and the oil fill tup probably should have been run outside the pan. Instead I lengthened it ran it below the oil pan bolts on the passenger side, and welded in a bulge on entire length of the oil pan to clear the tube. Ran a stock but ported intake manifold, the largest long tube clifford headers I had on hand, and a custom HEI Distributor. Along with the T-5 Transmission, and the 4.11 rear gears it was a very streetable combo.

I just kinda lost interest in it when the guy who owned the 5.0 Mustang it was built to suddenly passed away. Took alot of fun out of it. And when I purchased the LS2 Powered Solstice, I just did not drive it anymore. Didn't see myself owning another cammer until the California Sprint FB popped up a couple of years ago. This one will stay mostly stock.

thanks for info on this
That torque number is very impressive.
What cam and head were you running?

I have several to chose from and am thinking the .490 lift one is a good cam for an automagic(200-4R) with a corvette converter.

[camerjeff]

I actually ran a 68 1bbl head, with bigger valves (can not remember what valves I ran off the top of my head, Single LS beehive valve springs, the CR was 9.2 to one so it ran well on unleaded premium 91-91 octane. I tried a custom grind cam (still have it somewhere) but I was not happy with the results, so I ended up running a stock H-Cam. I also dialed it in for torque with an adjustable cam sprocket. Beating my buddies Mustang stop light to Stop light was the goal, and that it did very well.
The picture of me on the road course was a Trans Am Reunion event at Waterford Hills MI, I was actually faster than the 289 powered mustangs that day, I was not faster than the 1970 TA or the Red Mustang coupe running a very nice 351. Those 2 cars lapped me. But the rest of the mustangs were either equal or slower than my Yellow 69. I impressed the Mustangs quite a bit. One of them came up and said he was wrong about laughing at my car when I 1st opened the hood. He was driving the Blue GT350 replica, we battled it out for a few laps, until I finally got under him going into one of the corners, then the torque coming out of the corner left him behind.
Non of the straights on that track are long enough to let the lack of upper end HP hurt me that day. It was a fun car, but you can't keep them all. The guy I sold it to mad a T/A replica out of it. Nice build, but kinda a shame. The engine went to a father and son in Alabama. I don't know if they have done anything with it. But they drove up one weekend to pick it up.

[Cammer-6]

any details you can feed would be helpful

[Cammer-6]

Im looking at using LS1 pistons vs having them custom made($$$).
Has anyone used them and if so specs please.

[Cammer-6]

Found another on net
a 68 Firebird Sprint 4 speed
guy says its now a 302
Im not on FB but guy says his name is Ren Woodland
Comments ask if hes related to Jerry were unanswered.
If anyone has build info on this one please post it.

[sprintbird]

He is not related to Jerry. That is the engine that Brent H built. (Primatech) Brent is the best one to get the specs. Not very many are building strokers any more. Most are going with EFI and turbo builds. FYI

[Jeff Hamlin]

...

[Cammer-6]

whats the numbers on that one Jeff?
Ive lost Brents contact info If someone can PM it to me thanks

[Jeff Hamlin]

Originally Posted by Cammer-6

whats the numbers on that one Jeff?
Ive lost Brents contact info If someone can PM it to me thanks

It's a work in progress and this is what was shared thus far;
Getting close. Tested preliminarily at 7 pounds of boost. It was good for 289 HP and 315 lb-ft. Likely going to settle at 10 pounds. Goal is mid 330 hp, safely. Lot of effort for the outcome by todays standards but it should be fun.


Hey guys, this was originally a 1bbl head. There was an attempt to modify the head by a shop back east in 2009 or so. Extensive machine work was done to increase flow. They also installed oversized Chevy valves. But the valve stem length was wrong, they didn’t add dual springs and they threw in a custom Clifford cam (Rob Egbert now owns the cam) but they didn’t deck the cam tower to accommodate for the grind. It was a mess. When my dad passed the car along to me it probably had 30hp. The valves were burnt, the cylinder walls were marred up and it showed terrible wear for a car with under 40k miles.
When I got the car to Flagstaff in 2020 I tore down the motor and took the block to a local machine shop. Just an old shop in the back of an auto parts store. Nothing fancy. The block was zero decked and bored .30 over. They polished the crank, added ARP rod bolts and installed custom forged pistons from Ross Racing.
I sent the head to Jerry Woodland. It was one of the last he did before selling to Rob. He said he’d never seen anyone add oversized Chevy valves but he was able to make some modifications to the cam followers to accommodate the appropriate stem length. He also said that the actual machine work was very good so the head was salvageable. The rest of the appropriate modifications were made to the head, including dual valve spring and so on. The machine work and the modern head gasket increased the volume and pretty well offset the zero decked block, so my compression ratio sits at approximately 9.2:1.
I am running a 4bbl E cam. Again, nothing fancy or custom there. I also had a sprint damper refurbished and installed, however the engine hasn’t been dynoed with the sprint damper, yet. It peaked at 5200 rpm, with the 1bbl damper. HP and torque was just barely starting to taper off at that point so I don’t expect higher rpm to yield any additional power.
Funny thing, I spoke several times with Quinton at Primatech back in 2008/2009, trying to help my dad take a crack at modifying the motor back then. He gave good guidance and still had parts in stock. But we didn’t have the knowledge or resources. Primatech shut down shortly after. I still have the email chain. Those headers were certainly a missed opportunity, along with some other bits and pieces. The car has a Clifford intake and headers now.
More boost will produce more horsepower, no question. But will it handle 10 pounds? 🤞
Chris, if you have some insight as to what the limiting factor might be based on that conversation, I’m certainly curious.