valve spring clarification needed

[barnboyz]

reassembling 1941 9-n #59777 engine valvetrain, need confirmation on which valve spring i should use, it appears that archives call out for 2n6513 valve springs (longer) rather than 8n6513 (shorter) which was sold to me to be used as replacements.

 

[Bob]

All part numbers aside, if you have any experience around valves you will know when you are using the right spring. For this low compression, low RPM application, the correct spring will snugly seat the valve without a tremendous amount of pressure when closed, yet no looseness.

 

[NOXJohn]

Call Don or Derrick at nnalert. I can not seem to be able to keep it straight which spring goes on which type of valve but they always seem to remember.

 

[Dan]

You use the longer 2N part number springs EVEN if you upgrade the valves. I am the one who researched this and discovered MANY parts suppliers are sending the wrong valve springs for the 9N/2N engines when they are upgraded to adjustable valves. It is because the webbing between the top of the block and where the springs meet are thinner than the 8N versions - which were increased for cooling impriovements.

HTH,
Dan

 

[barnboyz]

thank you all for replying, this is what i observed after making a mock up assembly of both the long and short valve spring assemblies. i,d also like to thank hobo who took out the time to walk me thru the valve seat replacement procedure,which as it turned out wasn,t necessary. i had reground the valve seats to remove heavy pits and due to the stock removal from the valve faces/valve seats found little contact between the both of them. i did some checking into a sealed power valve spec chart from rock auto online and found that part#v2188(.312 stem dia.) was dimensionally close to the size of 8n6505a(.340 stem dia.) with the exception of the valve head dia.( 1.337 v.s. 1.277) the larger valve head dia turned out to make an excellent contact between the valve and seat, these were bought on a parts close out sale and also used the same valve spring keepers as 8n6505a. i used the old split guides and reamed them to .313 for a .001 clearance fit along with the 2nc6513 valve springs.