porting and polishing heads and look at what i found!

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porting and polishing heads and look at what i found!

Post  NITROUS FORD on December 27th 2015, 7:54 pm

Shocked I have the motorsport a460 heads with 2.300 int 1.88 ext valves. started taking them apart to port and polish them for more hp( heads flowed 390 cfm int @ .800) (280@ .800 ext) porting to get the int in the 430-440cfm range and ext in the 300-315 range and while I was taking them apart I found to inner valve springs were broke on two valves Shocked thank GOD i decided to do a port job on the heads or i wouldn't have found out until i tried to rpm the motor or a valve mite of let go Evil or Very Mad bought these from a guy who had them on a bbf 477 dragster! so he probably was rpming the heck out of the motor! all in all putting a brand new set of pac-1224 spring on the heads with the new port job so should work out good! Very Happy comp cam .835 int 786 ext dur @ .050 int 285 ext 300 lsa 115 santa

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Re: porting and polishing heads and look at what i found!

Post  rmcomprandy on December 27th 2015, 11:39 pm

NITROUS FORD wrote:Shocked I have the motorsport a460  heads with 2.300 int 1.88 ext valves. started taking them apart to port and polish them for more hp( heads flowed 390 cfm int @ .800) (280@ .800 ext) porting to get the int in the 430-440cfm range  and ext in the 300-315 range  and while I was taking them apart I found to inner valve springs were broke on two valves Shocked thank GOD i  decided to do a port  job on the heads or i wouldn't  have found out until i tried to rpm the motor or a valve mite of let go Evil or Very Mad bought these from a guy who had them on a bbf 477 dragster! so he probably was rpming the heck out of the motor! all in all putting a brand new set of pac-1224 spring on the heads with the new port job so should work out good! Very Happy comp cam  .835 int 786 ext  dur @ .050 int 285  ext 300   lsa 115 santa

If there are spring breakage problems, I would opt for the surface treated #1324 springs.

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Re: porting and polishing heads and look at what i found!

Post  NITROUS FORD on December 29th 2015, 10:03 am

well I measured the installed height on my  valve springs and  what do you know! they were set up at 1.950 and my cam requires a 2.000  install height. don't know how old the springs were (used heads)but I knew they were not up to the task on my new cam Shocked so with them being old and with the wrong installed height no wonder I found two broken inner valve springs Shocked remember installing new cam turning it over by hand and herd a pop! now I know what that was Mad
always check install height when buying used  heads! pirat

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