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I am running a set of the Retrofit Crane Roller Hydraulic Lifters in my 408ci stroker. I am having problems reving the engine. I cannot seem to get more than 7000rpm out of it before it flattens out. We have checked Keepers and valve springs, no sign of floating valves. I have tried a couple different cams and still the same thing. Any one else out there have any ideas??? I am thinking that the lifters are collapsing or something along that line??? Any help would be appreciated. Jeff [email protected]
 

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Whats the rest of the combo? 7000 RPM on a 408 is moving a little air.
 

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My Q exactly kim. .. good to see you are still at this. . . I would expect a 408 has a large intake valve (2.08), the valve is heavy. I would expect around 135# seat and 340# open on the spring pressure. Also to feed an engine with good heads to that rpm is going to be in the 700 lift range.

CStraub
 

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Hey Chris,

I posted in one of the other threads you were in recently... and I dont want to steal this one, but have you heard anything from Frances on the release of the NEW BT Big Block Ford head?

430 cfm out the box, supposed to be able to compete with the C460 head. There is a little engine building contest going on this year, and although the C head is in contention as a "Race Only" head, the BT's (didnt specify which one) is already approved.

Would be great to get ahold of a set of the new heads and use them in the contest.
 

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Yeah I know a little. . . wear do you want me to start. I had it in our booth at PRI. It should be in full production right now. There are 2 versions 4.600 bore and 4.360". The 4.600" will flow 550 cfm out of the box with a 2.500". The exhaust is a tru 75% of the intake. The 4.360 will flow 420 out of the box with a 2.350". Numbers are taken at 800 lift. The intake is being designed right now for an as cast piece. Sheet metal only. It is based of the C head, but quality far suppases what was then. Just looking at the head, it should flow 620 ported.

CStraub
 

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Ah the sheet metal thing is going to screw things up.

The 4.360 bore would be the ticket though.

Contest rules, max displacement, 477 cu in. Contest is best Torque/HP "average" between 2500 and 6500 RPM. Soooo long rod, good flow, "sharp" cam. And a cast 1 carb intake. It can be modified almost adnausium, but NOOOO sheet metal and no tunnel ram.

What rocker system is the big head using? My engine with the new cam will be on the dyno end of the month. If it doesnt see above 1000hp NA, there might be some ported Gen I BT's up for sale. Problem will be fabbing up the spacer plates to get the Tunnel Ram to bolt to either the new BT, or A C head.
 

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Spacers are in the works so don't worry. Forget the long rod on this head, you don't need it, the head is to good. Trust me... The intake is being done by one of my good friends and should be at the foundry by March.

CStraub
 
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