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-   -   355 Vortec Tuning. Watch the videos. (https://www.offshoreonly.com/forums/do-yourself-boating-budget/309717-355-vortec-tuning-watch-videos.html)

MILD THUNDER 03-16-2014 11:56 AM

Tune it on the water. Put a load on it. Sometimes you think you got it all set on the trailer, and you get to the lake, shift it into gear, and it will stall. Idling at 1100-1200, is no good for the drive you have there, when shifting in/out of gear....

Idle Air bleed size, idle feed restrictor size, and that BG idle Eaz deal, all can play a part in where you're mixture screws will need to be. Theres a reason they are adjustable and not fixed. Not all engines require the same settings. :helmet:

Trash 03-17-2014 02:36 PM

Install the wide band to get the AFR readings. That will take the guess work out of that aspect. No computer needed. Many wide 'kits' come with the sensor and gauge so you can monitor the AFR real time.

SB 03-17-2014 03:09 PM

I'll warn you right now, shifting that Alpha into gear over 800, especially over 900 will break it. I've broken a few at 900 and 1000 within a half dozen shifts or so.

Just a big FYI.

BUP 03-17-2014 03:43 PM

recommended idle is 650 to 700 for alpha drive in the water. Dog clutch hates higher idle while going into gear.

Fenderjack 03-17-2014 04:04 PM

Is there a chance that is to much carb for a 350 ??



John jr

CDShack 03-17-2014 05:33 PM

Although I've found 650s are more responsive on small blocks, 750s are doable with a little tweaking and jet work.

SB 03-17-2014 06:53 PM


Originally Posted by Fenderjack (Post 4091290)
Is there a chance that is to much carb for a 350 ??



John jr

My question is almost the same but:

Is there a chance the flat tappet cam wasn't broken in yet with this carb fooling around?

BTW: In cold air and non-warmed engine that air gap intake will make it t idle not worth a chit. It will probably want a handful more initial timing.

MILD THUNDER 03-17-2014 11:26 PM

I thumbing thru an ''Engine Masters" magazine a little while ago. They had a 500HP small block chevy. They tested 4 carbs.

Holley 4776 600 Double pumper.

Holley 750 Ultra HP

Holley 950 Ultra HP

BG 600

They dynoed each carb on the engine. From 2500-6500RPM. Not only did the 950 Ultra make more peak power, it made more torque than the rest of them, even in the low rpm range of 2500-3000.

The entire point they tried to make in the writeup, was that back in the 70's, bolting on too large a carb just didnt work well. With modern carb technology today, a larger carb, properly setup, can be very responsive, efficient, and work well. A modern 1050 Quick fuel, is a far cry from an 80's 2 circuit Dominator.

CDShack 03-18-2014 01:03 PM

We dyno'ed my big blocks and actually lost alittle going from 750's to 850's. But, having said that, the 850s were Demons the dyno guy sitting there and weren't set up for my motors. We were running at 107%VE and he wanted to see if he could get more air. Didn't work/


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