Moralesrx7

iTrader: (1)

i have a 408 being built right now should have it by the 3rd anyway i changed to the 408 in middle of building up a 346 my question is that i have p&p casting 806 5.7 heads that flow 298@600 on a std. bore one do i need to have these cnc to a 4.03 bore or will they work (im using a graphite gasket)and two these heads have a cc of 69cc ? or 66.7cc like the rest of the 5.7 heads because my cr seems to be 11.5 - 11.7 at 69cc. anything higher will be hard to run on pump gas.
i running a tsp giant cam,
ported tb,
ls6 intake,
42s inj,
jtr long tube 1 7/8 headers,
slp 85mm mafs
255 pump
ls6 port pump
and 100 dry shot
in a 93 fd rx7 w/ t56 and carbon driveshaft
thanks for any input also any ideas on rwhp would help

Richard@WCCH

iTrader: (3)

Unshrouding the valves will help slightly. You'll see a minor loss in compression ratio due to the larger chambers. I'm not sure what your budget is, but upgrading to larger valves (2.08"/1.600") will help out your combination. The larger bore of the 408's accomodates the larger valves well. Trading some compression ratio for increased airflow is ok in my book when running pump gas, especially when cr is in the 11.5:1 range.

Enjoy that hot rod :-)

Richard

Demon SS

iTrader: (3)

these will work ok, but IMO the combustion chambers need to be opened up to match the bore.

2c5s

iTrader: (11)

Any relief in the pistons?

Moralesrx7

iTrader: (1)

2cc reliefs, so the heads have to be cnc d to a 4.03 to work and do the 806 have a 69cc chamber? i did a search and cant find a postive answer thanks

Richard@WCCH

iTrader: (3)

All the stock 806's we've cc'd had a chamber volume of approx. 69cc. They'll probably grow to 71-72cc's after unshrouding.

Richard

Moralesrx7

iTrader: (1)

thanks any idea on power off the juice

kumar75150

what cam are you using?

Moralesrx7

iTrader: (1)

tsp giant cam http://www.texas-speed.com/item_deta...?ProductID=186