Machine J heads for dual spring?

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EP87

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Hi
Anybody know whats machining is required to install dual valve springs on J heads.
We've installed a comp cams xe274h cam in my son's 360 and the heads are
currenty at the machine shop. comp calls for a #995-16 springs and #740-16
retainers. there was a foot note. that said "machining require" I Called comp and asked if that ment just machining the guild for positive seals which the machine shop is already doing, and the guy said that was all but didn't sound to confident.
That would make sense since the outside of the comp spring is 1.437 and the
stockers look like there 1.5.
Anybody know for sure?
Thanks Richard

PS the guy from comp also said the stock retainers would work? but I have my doubts.
 
hi, the best thing is, use the 926 spring and 744 retainers. this is a single spring and is very tough. the machining required with dual springs is removal of the small pad at seat. the 926 is more than enough spring for your cam.
they will drop in. do not use stock retainers or locks.also, you can use rubber seals with the 926 spring. I use this spring on a 340 stock elim motor, they will last 5 yrs.
 
perfacar said:
hi, the best thing is, use the 926 spring and 744 retainers. this is a single spring and is very tough. the machining required with dual springs is removal of the small pad at seat. the 926 is more than enough spring for your cam.
they will drop in. do not use stock retainers or locks.also, you can use rubber seals with the 926 spring. I use this spring on a 340 stock elim motor, they will last 5 yrs.
Click to expand...

Thats sounds like a good idea, but I'm a little concerned about the installed height comp shows the 995 as 1.700 and the 926 as 1.800 would that be a problem?
thanks for your help .
Richard
 
hi, that will not affect anything, only seat pressure. I run mine at 1.730 installed height. even at 1.800 or 1.700 is ok.
 

Well I machined my heads for a triple spring, had to put in a narrow guide boss and they got replaced anyway becasue I went with the smaller stem size valves. I also gut the spring seat to install a spring seat cup and did all this with the corect installed height for the cam/valves/spring combination.

Cost a little more but if you need new guides it is the way to go. Also if you ever do break a spring you wont have a pistone swallowing a valve with dual or triple springs.

Something to think of..
 
I know you're not looking, but in the local area (look under the Buffalo, NY Craigslist), a guy is selling a set of 'J' heads with double or triple springs. I remember seeing them listed again, and again. The price was down to $100 last time I saw them.
Mike
 
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