Re: Removal of 496HO restriction plates
 

Thank You. No, we had GM use special rework to a special GM racing block so we could configure it as what we now call a GEN 7 symetrical aluminum head engine foundation. We are very proud of this motor and its mild manners, affordable pricing and phenominal braod torque based power. This new engine will also usher in something new to the industry. A motor that is delivered to the owner with its own ECM programming software so an interested owner or builder can take his laptop and fine tune his motor on the "fly" if he so chooses.

Re: Removal of 496HO restriction plates
 

Ray,, what about the stock exhaust re-work questions.. mainly price and expected hp gains..

Re: Removal of 496HO restriction plates
 

Chris:
Patientence my man! We are doing the flow testing now and what I can tell you at this point is that there are four seperate exhaust passages in the stock Merc (Gil) 496 manifold. All three are substaintilally different in the size of the openings under the riser. One will flow 240 cfm, one 202 cfm, one 180cfm and another 205 cfm. This in-balance coupled with low flow on three of the four ports hurts horsepower and is definitly improveable. We have done some minor porting on these in the past and seen 5-10HP gains on our 525Hp motors on the dyno. We are now carefully studying and reworking all four ports to flow about 250 cfm and in the next week or so we should get back on the dyno with a pair and really document the gains. Once we have done this and confirmed there is some realistic power improvement here for the dollar spent, then we will release the real gain numbers and the cost for the exchange manifolds. I suspect its going to be in the $400-$500 per pair exchange range, but thats a guesstimate and only if its worthwhile. Nothing before its time! Stay tuned I'll keep you guys posted.

Ray @ Raylar

Re: Removal of 496HO restriction plates
 

As always, thanks for the info Ray !! :)

Re: Removal of 496HO restriction plates
 

I'm still interested in some ideas on who to try calling around here out of the phone book for polishing the risers out?

Re: Removal of 496HO restriction plates
 

Does this info apply to the older Gil bbc manifolds as well?

Re: Removal of 496HO restriction plates
 

No, not the older Gil HP manifolds. they are a different design than the new Merc 496 manifolds and do not have the same port restrictions. The Merc 496 manifolds were designed and built by Gil for Merc.

Ray @ Raylar

Re: Removal of 496HO restriction plates
 

Thanks for the reply, not familiar with the new stuff.

Re: Removal of 496HO restriction plates
 

Ray, hows the progress on the reworking of the stock exhaust manifolds for the 496ho's? great idea, hope it works. Lets us know as soon as you get anything.
Thanks.

Re: Removal of 496HO restriction plates
 

Ray, any update on the worked exhaust manifolds? Went to your website, and found no info.

Thanks