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Title: Valve seat pressure Post by: Tumbles on June 17, 2005, 10:18:03 AM Have been toying with the idea of stainless steel red motor valves in my grey head, this so far has been workable. I want to uprate seat pressure, how far can I go before I start breaking stuff?
Tumbles Title: Re: Valve seat pressure Post by: HYSTERIA on June 18, 2005, 02:42:53 AM Hey Tumbles, I have just rebuilt my grey using red motor valves and 350 chev valve springs, from memory the spring pressure was 95lb ???. I also had a mild cam and head work done, twin carbs fitted and a set of extractors. the motor made 95 rwhp on the dyno and runs like a dream. I also took 80thou of the head to up the compression.
cheers J Title: Re: Valve seat pressure Post by: cer444 on June 18, 2005, 09:23:10 AM Hi Tumbles,
Your average standard Holden 253/308 V8 runs a spring pressure of about 110-120ibs Stainless valves are stronger because they are 1 piece,harder and basically desighned to have the living snotter revved out of them. As for a Grey motor I personally wouldn't go more than about 90-110ibs for a Grey motor(Unless your reving it hard all day) as you may start to chew lifters,cam lobes & timing gears. To give you another example my LC Torana drag car runs a roller cam with a seat pressure of about 240ibs with a ferrea brand stainless valve.(getting a bit away from greys here but you know what I mean!!) Title: Re: Valve seat pressure Post by: Tumbles on June 18, 2005, 11:51:06 AM Hysteria, the 350 chev springs were they the old or new motor, if they were new what make are they ie: crow cams ect? I am still undecided, do I use the twin or tripple strommies....If you don't mind me asking how far did you go with the red valves?
Thanks for the feed back on the pressure though (what is your redline when you douple seat pressure) I'll start doing some more sums..Yay! cer444, I know what the stainless valves are all about I had them in a stroker 186, my main concern was the rocker arms and bushes/bearings as I haven't found a suitable mod or upgrade in that department yet. Am designing eng to work between 2500 and 5500 with 500 oops facter built into it, like I said befor more mathes.... Tumbles Title: Re: Valve seat pressure Post by: HYSTERIA on June 20, 2005, 09:38:18 PM tumbles, Not sure of exact valve spring brand, I believe they are from a carbie fed 350 (early 80's). I'll check with my mechanic in the next couple of days and get back to you. I'll check on the valves for you too.
I've been told my motor will rev at 5500 all day but reving past 6000 will put a lot of pressure on the crank so that's a no no. ;) cheers Jay |