Thanks for the info, and pics! The valves are TA stainless, from what I see the exhaust valve is back it already.
Ordered valve seals, while waiting I figured I’d check to see spring pressure @ installed height and open. For 140 lbs on the seat I have to install @ 1.60 Open pressure is 335 @ 1.042 I’m pretty close to coil bind, but think I’ll be fine, coil bind is listed @ .990 I measured at bit less than .990 They’re TA 1450 350 super dual springs.
Unless my eyes are fooling me, that exh valve is not back cut , it’s tulip shape kinda makes it look like it’s back cut. sit the seat area on a flat surface with it back lit and you will know for sure. 335 psi open for a flat tappet hydro cam is going to require you to break the cam in on just the outer springs. If you can get at least a .010” feller gauge in between 6 of the coils at your max valve lift then your golden!
WOW thanks Steve for the detailed explanation, and pics! I was wondering how to smooth that short turn, your sandpaper sounds like the solution. I just received my new valve seals, but unfortunately can’t do any heavy lifting due to hernia surgery I just had, this sucks just sitting around.
In combination with the length of sanding strip I use tapered sanding roll’s , but I screw them on the mandrel backwards. They do not last as long like this, but it really helps to get that area cleaned up and blended into the apex of the short turn.
Jim your post makes no sense to me whatsoever! Are you talking about removing the flat wire damper that some spring set ups have? If so, are you making up for that lost pressure, but even if you are you can not compensate for the loss of surge control / stability that a flat wire damper provides. If your removing the damper for the sake of getting seal clearance and you are running a .530” type seal and 11/32” valves then you need to get the guides cut for a .500” seal, or just plain run a different spring set up with a bigger OD which will allow a bigger ID. Please note that I hate spring packages that use flat wire dampers as they will always become a problem sooner or later! I would sooner spend more money on a duel or if needed triple spring package to get rid of the flat damper,
I believe hes talking about the small coil spring on the seal itself. I had thought the same thing initially
If that’s what he’s taking about such is only done with the White Teflon seals for exh valves since they can run exh stems too dry especially in race motors where the lifters or push rods are restricted. These blue seals are not Teflon. Also a whole bunch of Aluminum aftermarket heads do not drain oil as fast as needed from the rear of the head with the typical angle that motors sit on. If you do this on the last two exh valves on each bank then you need to confirm that those 2 rear plugs are not showing signs of oil when the other 6 are not. Many times at the track with someone’s car with aftermarket heads I see light smoke out the rear of the car at the 1000 Ft mark, and this is a sure sign of overwhelmed rear valve seals, and maybe Intake valve wise also,
Did some spring measurements, height and pressure. My installed height of 1.74 that’s with retainer and spring cup/seat gives me less than 100 lbs. on the seat. If I reduce it to 1.55 with shims it gives me 135/140 lbs on the seat. But @ /1.55 spring height and .568 valve lift, that puts the spring height at .982 and 350 lbs over the nose. Coil bind is at .990 Another thing tripping me up was measuring spring pressure WITHOUT the retainer thinking “ spring height is spring height” BUT the retainer has an inner step for the second inside spring, so checking pressure @ height without the retainer was giving me bogus readings, I’m thinking “Why is this changing” then realized and looked at the retainer and WAAALAAAA. So I need new springs that have more beef
Was just looking at TA’s valve springs and wondering if I were to use the TA 1125 springs INSTEAD of the 1130 springs I have now if I could achieve my desired 140 or more pounds on the seat with NO shims just the retainer and spring seat. The 1125 springs say 125 lbs @ 1.90 height, my set up has the spring @ 1.74 installed height, OOOR would that push the on the seat and open pressure too high?????? Both springs use the same retainer. The reason I’m critiquing this is when I ordered the roller cam from TA they told me I could use the same springs I was using for my 413 flat tappet hydraulic cam, Tim said this was uncharted territory for the 350, and it’s probably why I see no other “Roller cam” specific springs listed for the 350. The TA 1130 springs I have now are only a few years old, they just don’t seem to last pressure wise, and wondering if my last time at the track the engine was laying over close to 6 grand, which was the first time it did that with the roller cam. These springs Peter out this fast?
Mark, What is the outside diameter of the outer spring and the inside diameter of the inner spring? I may be able to find a good alternative.
Mark, these would work good. The extra length will probably put the closed pressure around 150, have to measure to be sure. You could have the spring pockets cut deeper too. The seals in the kit wont work but you already have new seals: LS Series Beehive Valve Spring Kit, Complete Kit, 137 Lb Seat, .625" Lift, Vsk3P-Q (alexsparts.com)
