I will have a 406 roller motor
with 10 to 1 comp.
226/236 540/ 560 lift 112LSA
forged pistons with a 125-150 shot of NO2
Edelbrock RPM heads
and a Superram with 30 lb. injectors
and a totally custom ship its a MAP set-up

I don't know if this matters but I have a T-56 with 3.73's
thanks for the help

 

Defenatly 58mm. If you can find a bigger one go for that.

 

58mm, no doubt.

 

AS&M Monoblade

 

WOW I was expecting to hear that the 58 is way to big or something like that. Thanks for clearing that up. I especially like the comment about if I could find one bigger go for that! LOL!
The monblade was a good one too! Can you link me to the page that has the monoblade? I would like to see it

 

If you can find a link to arizona speed and marine they've got the monoblade in their inventory.

 

Try www.azspeed-marine.com

With 406cu inches, I would definately go with the 58mm TB.

I'm thinking about a 395 stroker, with that stroker I will buy a 58mm TB.

 

even on my engine the 58 isn't overkill.

 

Hey i'm building similar motor!! Anyrate where is this mono-blade i looked at AS&M and i can't find it on there site. A mono-blade would be usefull even though im using the factory Plenum

 

I couldn't find it at first either. You got to click on new products and look under there. Its pricey though $550

 

58 for that engine definetly.

 

Curious, if a 406 requires a 58mm TB, why does GM sell the 502 RAMJET with a stock 48MM, and it makes 500+ HP. You'd figure for the cost of that crate engine, if a 52 or 58mm produced more HP, GM would have sourced it from one of the aftermarket suppliers.

Would it make sense to say the larger displacement can draw more air through the same TB? Granted on a flow bench, the 58 will flow more than a 48, but when you put a larger vacum source behind the TB, the flow rate changes as does the velocity, correct? I believe the flow bench uses xxx CFM at yy inches of mercury, right? If the mercury reading changes, so would the flow.

Comments?

Mark.

 

For a good price on TBs, go to Summit Racing (www.SummitRacing.com) or Excessive Motorsports.

Summit Racing carries Edelbrock, BBK, and Holley TBs 52mm and 58mm. But I think that Excessive Motorsports has a slightly lower price on the Edelbrock TBs.

Hope this helps,
Doc

 

is that webiste excessivemotorsports.com? I was thinking about the monoblade maybe if I save up for it

 

Please do us all a favor and run the 48mm and then switch to a bigger one. If that 502 doesn't need one (58mm), you don't.

 

It would probably make more power with the 58mm TB. Probably at higher RPM.

 

I found that mono blade. It's under new products.

http://www.azspeed.com/newitems-8.html

They recommend you do not use it on a small block!

 

Correct me if I'm wrong but I believe TPIS also offers a monoblade TB. They advertise it flowing 1300CFM. Of course it could just be them stealing the AS&M one and raising the price, they enjoy doing that sometimes.

 

BTW.... Mark_ZZ3 made an excellent point. TB ratings never consider the changing vacuum of the engine. Maybe these monstrous TB's are not need. GM didn't seem to think so on the Ram Jet.

 

true but I bet that a 350 could make 1hp/per cubic inch with a 48mm as well. Maybe they messed around until they got the advertised 502 hp from it

 

GoFasterFirebird, what role do you think plenum volume plays in TB selection? For example if you had a 406 LTR TPI and a SuperRammed 406, all else being equal, assuming ideal air delivery after the plenum, which one runs out of breath first?

 

I could be wrong, but I dont recall that the 502 Ramjet has any claims that larger TB's did not improve the power output. The air demand of that engine is also entirely different and hard to compare straight across to a 350.