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BADDTA · 03-10-2018, 02:36 PM

Quote:

Originally Posted by jm455ho

Wow, just realized you had almost the same numbers. I wasn't paying attention, and thought yours were reversed with higher HP and lower TQ.

It’s all good. Just givin ya sh!t.

Brian

Jim Robertson · 03-11-2018, 12:52 PM

This very streetable 466 made peak tq of 621 lb-ft at 4700 and a peak of 616.5 hp at 5800. Mike McCarty must have been there hiding in the corner. :-) We took extra care with the mods to the heads and intake to extend the RPM a few hundred over previous similar combinations. Idled very nicely at 1050 at a steady 10" vacuum. Going in a restored 77 Can Am...That looks like all the other Can Ams. If you run across a Can Am with Texas plates be careful picking on this one. He plans to autocross, drag and street drive it. Giddy up.

PAUL K · 03-11-2018, 01:25 PM

Quote:

Originally Posted by Jim Robertson

This very streetable 466 made peak tq of 621 lb-ft at 4700 and a peak of 616.5 hp at 5800. Mike McCarty must have been there hiding in the corner. :-) We took extra care with the mods to the heads and intake to extend the RPM a few hundred over previous similar combinations. Idled very nicely at 1050 at a steady 10" vacuum. Going in a restored 77 Can Am...That looks like all the other Can Ams. If you run across a Can Am with Texas plates be careful picking on this one. He plans to autocross, drag and street drive it. Giddy up.

Great build! Impressive.

BruceWilkie · 03-11-2018, 04:35 PM

Nice Jim. Glad it's more torque/hp than I estimated. Thanks for sharing.

Dragncar · 03-11-2018, 05:17 PM

Jim, you can port some heads. Those are VERY good numbers for what it is. Numbers like "pump gas 600HP E heads" get only with bigger cams.
I have a iron headed TRW 455 that does good. Same 9.3 CR but with round port HOs. About 570HP by weight/ET/MPH. But with bigger solid roller that is not very streetable.
People can seem to give away those 6 X-8s. Just gave them a reason to think about builds with them. I have a set given to me.
Again, nice job.

68azbird · 03-11-2018, 05:51 PM

So I was off in 4 ft lbs of torque

tom s · 03-11-2018, 05:55 PM

Hell that was EZ for Jim,he got 292 on my friends 127 heads with a 2.02 intake!Tom

Tom Vaught · 03-11-2018, 09:14 PM

Quote:

Originally Posted by Jim Robertson

This very streetable 466 made peak tq of 621 lb-ft at 4700 and a peak of 616.5 hp at 5800. Mike McCarty must have been there hiding in the corner. :-) We took extra care with the mods to the heads and intake to extend the RPM a few hundred over previous similar combinations. Idled very nicely at 1050 at a steady 10" vacuum. Going in a restored 77 Can Am...That looks like all the other Can Ams. If you run across a Can Am with Texas plates be careful picking on this one. He plans to autocross, drag and street drive it. Giddy up.

Looks like a tie to me with my good friend Mike McCarty. He hit the torque number on the nose.

His hp was 594. My HP number was 598 hp.
I did not post a torque number.

Last Time I looked 598 HP is closer to your Dyno HP number vs 594 Hp but Mike did give you both numbers.

Ton V.

Jim Robertson · 03-11-2018, 09:19 PM

tom s I thought only bad news traveled fast...Dang! I told the customer about his 127 heads yesterday. Those 127s have some roof height that is missing from the 6X and they responded nicely. Thread for another day.

68azbird I wish it made 680Hp.:-)

tom s · 03-11-2018, 09:32 PM

Jim,so few people have actually worked on those heads that are still around.A head that was born around 1960,I know Nunzi had got over 300 on a set of 980s years ago.He told me he would never do a set that high again.He said the 290s was about as far as he liked.The 980s had a lot better exhaust.Tom

Jim Robertson · 03-11-2018, 10:17 PM

127 exh went 242 cfm. These will make a great set of heads. There is more than one reason Smokey was successful with the Pontiacs of the early 60s.

68azbird · 03-12-2018, 11:09 AM

Quote:

Originally Posted by Jim Robertson

68azbird I wish it made 680Hp.:-)

A few tweaks and an intake manifold change and it would be there.

455GRIN · 03-12-2018, 11:45 AM

Hi Jim, great numbers, hope I'm next. Going to have to step back on cam a bit for my combo with stock rods short block.
Sean

Jim Robertson · 03-12-2018, 02:02 PM

Hello Sean. Lots of cool projects taking shape here including yours. Your heads are smaller and thus will peak at a lower rpm.

On the subject of intake manifolds...We did believe there were some good info to be gained by testing other components with this engine combination. So, we tested 6 different intake manifolds on this engine along with another set of ported 6X heads with the same manifolds. In addition to Performer RPM we tested a ported Nash designed intake (aka Warrior & SK), stock Torker II, Offenhauser 360, Ported OEM (1972) iron intake and Performer Pontiac. The results were eye opening. We try to accomplish R&D regularly but it is hard to fit it all in with the cool projects already on the to-do list. Has anyone run an Offy 360 intake? Our dyno test may be one of the very few ever recorded. How much did we loose with the Performer Pontiac? Is an OEM iron intake worth any more than scrap metal prices?

BruceWilkie · 03-12-2018, 03:19 PM

Manifold test info would be interesting. Offy h-rise has me curious. Seems like it's all plenum.

slowbird · 03-12-2018, 03:42 PM

Would love to see those test results!

Gary H · 03-12-2018, 05:00 PM

Outstanding numbers Jim!! At a relatively low compression ratio to boot. I'm impressed to say the least.

Would love to see an intake manifold summary of your testing if you care to share.

Dragncar · 03-12-2018, 05:24 PM

Quote:

Originally Posted by slowbird

Would love to see those test results!

Me too!

jm455ho · 03-12-2018, 11:40 PM

Please, do tell on manifold testing.

BADDTA · 03-13-2018, 02:52 PM

Great job Jim! Outstanding as expected.

Brian

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