I am getting close to getting my engines together and was about to order some carb spacers for my 496's with dart intakes.

Any suggestions regarding the two different types of carb spacers.

*the open type
*or the 4 hole ones

personally I would think the open type considering their going on a open plentum single plane?

Any dyno results as to either of the two???

Thanks,
John

The open spacer is better for top end speed because it inceases fuel / air fogging in the manifold prior to the runners. The 4 hole / individual runners are better for lower speed transition in the same fashion as dual plane manifolds (so I've read and been told). I've got one of each and I plan on figuring out which one works better. The 4 hole style might take up some mid range slack where my single plane manifold might cause hiccups. The open spacer I'll try when the engine is broken in and I want all out speed so I can see if it makes any difference.

I'd love to see if anyone has any dyno results or other flow data.

Another question I'd like to throw into the ring is: is there any bennefit to a 2" spacer instead of a 1" spacer? And is it worth trying both at the same time? (4 hole, then open, then manifold)

Thanks GR... with all the dyno time i had down state years ago i never can recall checking these. Raylar among others probably has this data. Perhaps we can get him to post regarding our discussion. Maybe I'll PM him to see if he can post. It's always good to hear right from the guys who have the knowledge and the data to back it up. As you know I'm sure there are many factors that may apply. I have used them in the past and they were always the open ones and only an inch. Never really expermented much to really give myself as well as anybody else an honest aswer. Of course you'll hear from time to time that it will raise your top RPM by 100 to 200 RPM. Probably doubtful however I don't honestly know. Seems though in a sense it would be like simulating a runnel ram.?

Try a HVH super sucker, you'll like the dyno results, but' try it after testing with-out it first.

Agreed.

All the open spacers will do is move the power into higher rpms. The open ones work better on dual plane intakes.

I use the HVH on my 496. I believe it picked me up 100-200 RPM. According to my "seat of the pants dyno" I dont feel there was any negative impact by using it. I am using an 850 Demon carb and a Victor Jr intake with the 1 inch spacer. The condensation that forms on it when running is pretty interesting too.

I guess a good thing to do would is buy one and run with it and with out it to see if it helps out. The design appears to make good sense (HVH Super Sucker). The results will be another. I'll be sure and post the results. Thanks for the input guys.
John

Please see post #22 here:
http://www.offshoreonly.com/forums/g...-i-need-3.html

Feel free to read my article here:
http://marineperformancetechtalk.com/carb_spacers.htm

If you do an advanced search in OSO's search under 'super sucker' and for author put in 'sb' you'll see much of my ramblings.

Also, feel free to ask questions but you'll need to tell me all engine specs including your top rpm / carb / flame arrestor man and size for me to make a suggestion for you.

Carb spacers are a part of my daily life. I eat, sleep, and drink the stuff.

Thank you for the great info. Much appreciated.
John

I gained 25hp Dyno HP but using a HVH 1" one.800 hp 632.
So they work.