I will be testing the limits of a stock '68 Mustang block with the girdles soon. Read about the results in FSC magazine. I do think they will help, engine builder Chris Holbrook has had some experience with these and he says the do in fact work. I believe him. I am very anxious to make 650 with a stock block! I'll keep you guys posted. -Jake
Be careful about trying to prove something, Jake. You know....that whole "don't confuse me with the facts...my mind is made up" kind of thing. Any minute now somebody will ask you who Chris Holbrook is.
Just one little sidenote. There is a difference between ultimate strength testing and endurance or fatigue testing. A short deck W will probably hold up 800 hp or more for a couple times down the strip before it lets go. That's ultimate strength. Endurance or fatigue testing means that you could run the engine all day every day and not see a block failure. Since these valley girdles are more to improve endurance, testing should include a LOT of hours at either full power or something north of 90%. Just a recommendation for Jake.
Well let's put it this way, I made 530-550 on motor around thirty times on the dyno. And even before we did that I was told that couldn't be done. Granted I will be pushing this version of my 347 further than 550 (hopefully) with a fogger, I'm really just curious to see if what Horsepowersales says is true. If the block does give out I have another stock block I plan on filling halfway with Hard Blok. That, combined with a steel main girdle and valley girdle should hold up. I know a certain EFI Renegade racer that has the same setup going 8.50s. Not trying to prove anything, just want see what happens. I do think they will work up to 650, maybe 700, but I could be wrong. 550 is nothing to sneeze at either, from a stock block anyway. Also, this is an early block (possibly a Mexican block? Does anyone know how to tell?). I got my RHS heads yesterday, the fogger gets plumbed next week, and I hope to be on the dyno the first or second week in April, before the NMCA season opener.
Look for "HECHO IN MEXICO" cast into the valley. Also, main caps are thick. Same as the old HiPo 289 caps.
Mexican block ....and on the outside of the block there are usually 2 "nubs" that stick out from the face of the block, one on each bank just about an inch or so down from the deck surface. Once you see one that has the nubs, you can't miss them.
