Valve springs/specifications for a 40 Merc

F1 Flathead

F1 Flathead

Member
As mentioned in another thread, I have my 40 Merc motor down for a valve job since it appears I have some valves hanging up. I'd like to check the valve springs for proper load. Does anyone have the spec? Also can I get a recommendation for buying replacements if needed? The previous owner said that he installed a "3/4 race" cam so it may not be stock. I plan to check the lift to confirm. I see that it already has adjustable lifters. Should I buy some higher load springs if the cam is, in fact, a performance version?
Thanks,
Dan
 
My Motors Auto RepairManual calls for ("minimum valve spring pressure, pounds @ inches, length new --- 37 @ 2 1/8")

Vergil
 
F1 Flathead said:
As mentioned in another thread, I have my 40 Merc motor down for a valve job since it appears I have some valves hanging up. I'd like to check the valve springs for proper load. Does anyone have the spec? Also can I get a recommendation for buying replacements if needed? The previous owner said that he installed a "3/4 race" cam so it may not be stock. I plan to check the lift to confirm. I see that it already has adjustable lifters. Should I buy some higher load springs if the cam is, in fact, a performance version?
Thanks,
Dan
Click to expand...

If you do in fact have a "3/4" cam it might be cheap insurance to put a set of Zephyr springs in.
 
Thanks guys. It took me forever to get the LH head off last night. I hammered, Kroiled, made up some pullers that fasten into hollowed out spark plugs, even tried the old "rope trick". Finally got it off after about 3 hours. I will get the valves and spings off this week and give everything a good going over.
Dan
 
Pete said:
If you do in fact have a "3/4" cam it might be cheap insurance to put a set of Zephyr springs in.
Click to expand...

I agree, Valve springs are cheap so install some new ones.

I use Zepher Springs in all my engines with a after market cams. They work very well unless you are running a full competation cam, which would be too wild for the street.

If your engine in fact does have an aftermarket cam, stock springs may not be enough.

Chris
 
CWPASADENA said:
I agree, Valve springs are cheap so install some new ones.

I use Zepher Springs in all my engines with a after market cams. They work very well unless you are running a full competation cam, which would be too wild for the street.

If your engine in fact does have an aftermarket cam, stock springs may not be enough.

Chris
Click to expand...
Chris,
Thanks for the feedback. Where's the best place to get a set of Zepher springs?
 
I checked the lift on my cam and it is nearly stock lift. I can't check duration but my guess is that it is an Isky 77 or 88, not a Max 1 or 400 Jr which both have much higher lift. I checked the valve springs and they all measure over 40 lbs at 2 1/8 inches so I think I will try and use them. The lifters and guides were all covered with a real sticky substance (old, overheated oil?). I'm thinking that my problem will be fixed when I get it all back together.
 
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