big block valve wsprings

[Wayne M.]

Re: big block valve wsprings

the bad retainers had a "O" on them and the later ones have a "T" on them. ......

Clem -- Yet the '65 thru 'July '69 P&A catalogs show the "T" stamped retainer #3859909 as being for '65-9 Pass (396) (exc. Sp. H/Per.), and '65 (?)-'69 Pass., corvette (427) [no mention of whether all performance versions or not].

but, surprisingly, the "O" is still around:
'65 [only] Pass., Corvette w/Sp. H/Per. (396) is the only year that still, in July '69, calls for the "O" stamped retainer # 3864900.

Below is a thumbnail of the "T" stamped retainer, off a set of January 1968 oval port "215" heads with the single spring and flat damper, and which I believe to be original to the heads.

[Clem Z.]

Re: big block valve wsprings

Clem -- Yet the '65 thru 'July '69 P&A catalogs show the "T" stamped retainer #3859909 as being for '65-9 Pass (396) (exc. Sp. H/Per.), and '65 (?)-'69 Pass., corvette (427) [no mention of whether all performance versions or not].

but, surprisingly, the "O" is still around:
'65 [only] Pass., Corvette w/Sp. H/Per. (396) is the only year that still, in July '69, calls for the "O" stamped retainer # 3864900.

Below is a thumbnail of the "T" stamped retainer, off a set of January 1968 oval port "215" heads with the single spring and flat damper, and which I believe to be original to the heads.

GM never threw anything away till the supply was used up. i guess they had run the numbers and found it was cheaper to have some blow up rather than throw out all the bad inventory. they still have parts in the performance catalog that have not been used since the 60s.

[Don L.]

Re: big block valve wsprings

what are the valve springs used on the new Chevy BB crate engines

(Exact) Original design springs cannot be made today. The wire that was used in springs 40+ years ago isn't used (or likely even made) today. Today, the wire is much higher performance and sometimes even a different profile (not round). Processing methods are much, much more advanced today too.

GM doesn't make valve springs. At work, my company makes engine valve springs for most all OEMs, including the General. Last year, more than 60 million.

Custom springs are designed and manufactured every day. Not a sales pitch - let me know if I can help. I'll sick one of the techs on it and see if we can help get something for this application.

[Keith B.]

Re: big block valve wsprings

yes I just bought a GM cam 24502611 used in the new crate 454HO. and would like to know what valve springs should be used with this cam

[Clem Z.]

Re: big block valve wsprings

yes I just bought a GM cam 24502611 used in the new crate 454HO. and would like to know what valve springs should be used with this cam

how about these springs ?? http://www.race-mart.com/GM_Performa...-14097002.html

[Clem Z.]

Re: big block valve wsprings

yes I just bought a GM cam 24502611 used in the new crate 454HO. and would like to know what valve springs should be used with this cam

remember this roller cam requires the use of dist gear 10456413

[Patrick B.]

Re: big block valve wsprings

The napaonline.com buyer's guide lists it for use on what looks like all big blocks from '65 into the seventies, so it appears to be an OE replacement, but unfortunately no force/rate data is listed for it.

Someone will have to buy one and have it tested to be sure.

It's a dual spring with a damper sandwiched between the two springs... interesting.

Duke

The Northern Auto Parts entry for the VS-1581 gives the detailed specs below, and it does not mention any damper- just an inner and outer spring like the GM spring. It has the same open and closed force specs as the GM spring, except that the open pressure is measured at 0.62" valve lift instead of at 0.50" valve lift in the case of the GM spring. This makes sense because the GM spring rate is 450 lb/in while the Speed Pro spring is 370 lb/in.


Speed Pro Chevy Big Block Performance Valve Spring with a 1.460" O.D. good to a .590" max lift.
Valve Springs represent the most commonly overlooked item when rebuilding your engine or replacing your camshaft. A new cam offers limited performance improvement if you have weak springs. It is always a good idea to check your springs or replace with the recommended aftermarket spring.

Specifications
Type . . . . . . . . . . Performance Valve Springs
Position . . . . . . . . Complete Assembly
O.D. . . . . . . . . . . . . . . . . . . . ...1.460
Max. Lift . . . . . . . . . . . . . . . . .. 590
Closed Pressure (Lbs.) . . . . 105
Closed Height . . . . . . . . . . . . 1.88
Open Pressure (Lbs.) . . . . . 338
Open Height . . . . . . . . . . . . . .1 .25
Coil Bind Height . . . . . . . . . . 1.200
Approx. Rate/inch . . . . . . . . . 370
__________________________________

Type . . . . . . . . . . Performance Valve Springs
Position . . . . . . . . . . . . . . . . . Inner
Closed Pressure (Lbs.) . . . . 29
Closed Height . . . . . . . . . . . . 1.78
Open Pressure (Lbs.) . . . . . 118
Open Height . . . . . . . . . . . . . .1.15
Approx. Rate/inch . . . . . . . . . 140
__________________________________

Type . . . . . . . . . . . . . . . Performance Valve Springs
Position . . . . . . . . . . . . . . . . . O. uter
Closed Pressure (Lbs.) . . . . 76
Closed Height . . . . . . . . . . . . 1.88
Open Pressure (Lbs.) . . . . ... 221
Open Height . . . . . . . . . . . . . .1 .25
Approx. Rate/inch . . . . . . . . . 229