The Supercar Registry

The Supercar Registry (https://www.yenko.net/forum/index.php)
-   Boulder Motorcar (https://www.yenko.net/forum/forumdisplay.php?f=141)
-   -   Harry Mann 68 L78 / L88 Camaro (https://www.yenko.net/forum/showthread.php?t=130432)

Crush 12-23-2022 02:06 AM

Quote:

Originally Posted by dykstra (Post 1609013)
Great to hear Tim!!

And it will be great to hear, new exhaust?

napa68 12-23-2022 04:23 PM

Quote:

Originally Posted by Crush (Post 1609045)
And it will be great to hear, new exhaust?

That's the plan. Considering my options right now. Certainly want something that would be true to the period. The consensus between both Eric and my engine builder the current exhaust could be costing 80-100hp.

The exhaust may also help along the engine vacuum a little bit too (4" at an idle)

Crush 12-23-2022 05:25 PM

“my engine builder the current exhaust could be costing 80-100hp.”

Nice over 500 incoming?!

napa68 12-24-2022 10:48 AM

Quote:

Originally Posted by Crush (Post 1609122)
Nice over 500 incoming?!

:naughty::naughty::naughty::naughty::naughty:

TimG 12-24-2022 12:03 PM

Merry Christmas, Tim. I can't wait to see the end product.

napa68 01-04-2023 02:03 AM

2 Attachment(s)
Eric finished up the carb today. I must say, I was particularly surprised and impressed as he wanted to know some VERY specific things about the build. Including........

-header primary size
-header collector size
-exhaust size
-exhaust configuration
-muffler choice

That in addition to particular engine and vehicle specs. Once again proving there are no "bolt on" parts in a build like this.

I made the choice to make it look like it had been installed early on. My mindset was to give the appearance the carb received nothing more than a carb kit.

Below, is Eric's tutorial as written on Facebook.......

"Holley 4781 850 double pumper for Tim Schuetz of Boulder Motorcar Company.

This one's destined for a "Day 2" style '68 Camaro with a pretty hairy-chested 427 that's running an old school L88 bumpstick. As such, idle vacuum is almost non-existent, so the carb needed a few tweaks to allow it to function on the snotty 427.

Idle air bypass holes were added to the primary blades to allow the curb idle throttle position to jive with the transfer slots. The idle circuit was also recalibrated to provide a suitable range of adjustment.
Boy...all that sure sounds awfully familiar. .🤔...

All that explains why it's idling at 1400+ on my test engine--I wanted to set it up close enough where Tim could install it and get it running without having to futz too much with the adjustments.

This one's set up fairly similar to the 1000HP I built for my chevelle which probably has about the same idle vacuum as Tim's 427.
I've ran the Chevelle's 1000HP on the test engine several times, and obviously when it was adjusted for a nice 900 rpm 12.5-1 idle on the test engine, it wouldn't even THINK about idling on the 496 in the Chevelle--which is precisely why carburetors have adjustment provisions. 😁👍

Oh yeah, before I forget--we sourced this core off of eBay, and it had that big blob of orange silicone sealing off the choke rod hole when we picked it up. I mentioned I planned to remove it and install a brass block-off plate but Tim said he kind'a dug the look of the silicone, so we left it on there. 😉😁"

Xplantdad 01-04-2023 08:58 PM

Eric rocks!!:headbang:

napa68 01-05-2023 12:46 AM

Quote:

Originally Posted by Xplantdad (Post 1610327)
Eric rocks!!:headbang:

Yes he does:headbang:

RPOLS3 01-05-2023 01:16 PM

This car was crazy cool before - now it will be over the top.

napa68 01-10-2023 09:03 PM

1 Attachment(s)
Progress....... Happy with the preliminary pulls after getting everything broke in. Now run the valves, have a look around, check torque, and switch to Eric's carb.

Tomorrow, some tuning and power pulls


All times are GMT. The time now is 03:57 AM.

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2025, vBulletin Solutions Inc.


O Garage vBulletin Plugins by Drive Thru Online, Inc.