Thanks for the info. Sounds like just the outer should be ok. on the uninstalled height I was just showing how much taller the iskys were.

Kenny  Onalaska, Texas

The stated pressures are with the inner springs in place.  Without a new set of Isky 6005 valve springs sitting here in which to measure, I can’t say for sure exactly how much pressure the inner springs are worth in both seat pressure and over the nose pressure.  What I did have here was a used 6005 spring and while it measured 130 lbs. at 1.800” with the retainer in place, with the inner spring removed the pressure is 90 lbs. at the same 1.800”.

 

The uncompressed spring heights really don’t do much for knowing what the final tension rates will be.

Lorena, Texas (South of Waco)

talk about a blond moment. forgot all about the step in the retainer.

Kenny  Onalaska, Texas

Kenny:

The valve guide boss has to be machined smaller all the way to the outer spring seat to use the inner spring.  The spring is shorter because there is a step on the spring retainer which reduces the installed height of the inner spring.

John - "The Hoosier Hurricane"

 

I know this is a old post but it kinda fits my question. Ted was this using the inner and outer springs. If I leave out the inner spring do you know about how much this will change the spring rate on the 6005 springs. The following measurements are uninstalled lengths. My stock springs were 2.080 tall. The isky outer is 2.440. The isky inner is 2.075. Is this shorter length on the inner because of the valve guide boss.

Thanks,Kenny

Kenny  Onalaska, Texas

Prior to installing a Isky E-4 into my engine I was hassling with the spring pressure issue.  Past posts here by Hoosier and others indicated the Isky recommendation for pressure was excessive.  I looked at JMs recommendations on his mildest cam and saw stock was OK, VS95 recommended.  So the stock spring heights were set for 90lb seat.  Then a passage in a 1956 shop manual surfaced, stating not to overshim springs or breakage could result.  That piece of info combined with the realization that these stock springs were 50 years old led to the ordering of the JM VS95, which were adjusted in height for a seat pressure of 90-95 lbs., with 90 being the target.  Valve train is stock 1.92 intake and 1.52 exhaust valves, with slight weight reduction in one piece keepers and after market pushrods.  The use of lighter stainless valves, or either of the two lighter and smaller stock intake valves, should make the higher spring pressures even less important, I think.  The truck and engine will be driven very conservatively with redline of 5000, rarely to be achieved. 

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

Tim: I just checked J. Mummerts Spring listings & std. stock valve springs are listed as 70 lb on the seat & 165 lb open. Next he lists springs c/w damper, at 95 lb on seat & 235 lb open.

Paul

Mike.  As you mentioned, Iskenderian lists the p/n 6005 valve spring for use with all their Y camshaft offereings regardless of intended usage.  But digging deeper into the Isky catalogue, the same p/n 6005 spring is also being listed for the small block Ford V8’s, 6 & 8 cylinder scrub offerings, and Ford 240/300 sixes.  Considering that I just don’t have any problems with Isky cams and lifters when using these springs just means Isky is doing something right on their end.  But playing with the rocker arm ratios does net some different over the nose pressures for the Isky Y cam lineup with the p/n 6005 springs while maintaining a 135 lb seat pressure.

 

With 1.43:1 rockers.

Isky E-4             264 lbs

Isky RPM-300   271 lbs

Isky F-300         269 lbs

Isky 505-T         285 lbs

 

With 1.5:1 rockers.

Isky E-4             270 lbs

Isky RPM-300   277 lbs

Isky F-300         276 lbs

Isky 505-T         292 lbs

 

With 1.54:1 rockers.

Isky E-4             274 lbs

Isky RPM-300   281 lbs

Isky F-300         280 lbs

Isky 505-T         297 lbs

 

With 1.6:1 rockers.

Isky E-4             280 lbs

Isky RPM-300   287 lbs

Isky F-300         286 lbs

Isky 505-T         304 lbs

 

With valve spring rates being linear, then installing the Isky p/n 6005 springs at a 1.800” height instead of 1.750” will give a seat pressure of 118½ lbs. if it was originally at 135 lbs.  This reduction of 16½ lbs in seat pressure is then also a 16½ lb reduction in over the nose pressure.  And that’s enough fun with numbers this early in the morning.

Lorena, Texas (South of Waco)

It has always been a curiosity to me that Isky calls for the same spring pressures on all of its 4 Y cam offerings, which range from a high rpm of 7000 rpm using the most radical cam, to 5000 rpm on its mildest:  135 seat 285 open. 

Mike, located in the Siskiyou mountains, Southern, OR 292 powered 1946 Ford 1/2 ton, '62 Mercury Meteor, '55 Country Squire (parting out), '64 Falcon, '54 Ford 600 tractor.

Paul,

What I listed did not come from a book, We have a box of springs in the shop (we buy them by the gross) so I took one spring and measured it at those heights, and that is what I posted. I guess we put a  little better than stock springs in our rebuilds.

   God Bless.   Tim                           http://yblockguy.com/

350ci Y-Block FED "Elwood", 301ci Y-Block Unibody LSR "Jake", 312ci Y-Block '58 F-100, 338ci Y-Block powered Model A Tudor

tim@yblockguy.com  Visalia, California    Just west of the Sequoias