Isky valve springs

[RootesRooter]

I installed Isky valve springs during my SV restoration. I've forgotten the spring pressure, but it's not a huge amount higher than stock.

With resurfaced lifters and lobes on the KB cam, I expected the 1725 to be like-new quiet. Instead, the valve train is noisier than before. The clatter doesn't seem to be confined to any one valve or lifter. Oil seems to be going everywhere it should along the rocker arms.

Is more noise normal with stronger valve springs?

 

[RootesRacer]

I installed Isky valve springs during my SV restoration. I've forgotten the spring pressure, but it's not a huge amount higher than stock.

With resurfaced lifters and lobes on the KB cam, I expected the 1725 to be like-new quiet. Instead, the valve train is noisier than before. The clatter doesn't seem to be confined to any one valve or lifter. Oil seems to be going everywhere it should along the rocker arms.

Is more noise normal with stronger valve springs?

The spring rate usually doesnt impact the sound much, what does is the lack of "quieting" ramps as the cam rotates from the base circle into the lobe.

More aggressive cams have less transition and are noisier.

 

[Bill Blue]

Do you have the correct lash for the KB? It is not unusual for cam grinders to specify a lash different from stock.

Bill

 

[Ragg Mopp]

I installed a KB grind cam in my car and used the grinder's recommendations of 014 for both intake and exhaust vs the factory 012 and 014 and have found it to be noisy. I used a length of hose and my tuned ears and decided that the noise was coming from the intake valves only. I plan on setting the intake back to 013 to see how this does but expect to be back to 012 before I am done.

 

[agmason54]

My 1725 lump runs Isky valve springs,lifters and pushrods. I set my intake lash at 10 and exhaust at 12 thou.Tiger Tom himself gave me this tip.It seems quite and but still sounds British.
Agm

 

[RootesRooter]

Is there real science to lash settings or did the factory just find by number of customer complaints that 12 and 14 didn't seem to burn many valves?

10/12, you say per Tiger Tom. 14/14 per the KB cam grinder (Delta?). 13/13 per Rootes for the H120 cam.

I'm tempted to try Tiger Tom's numbers developed using Isky springs, but was he using a KB cam or a stock cam - or does it matter?

My 1725 lump runs Isky valve springs,lifters and pushrods. I set my intake lash at 10 and exhaust at 12 thou.Tiger Tom himself gave me this tip.It seems quite and but still sounds British.
Agm

 

[mbruskin]

I also have the KB grind on my cam and Delta Cams told me to use .014 on both intake and exhaust, but with the engine COLD, This was just last month and with 250 miles on the cam it is very noisy.

Murray

 

[agmason54]

I set all my engines at 10&12 regardless of Isky cam and lifters. I have set my valves only twice in over ten years.Once when I put the engine together and about 100 miles later. I have not touched them since in over 10 years and many cross country trips. Hardened exhaust valve seats is why. It's the only way to go.That is if you really want to go anywhere in an Alpine.
AGM

 

[Tom H]

I have the KB grind and set my valves using the Std 12 and 14. And they are reasonably quiet when fully warm. But I find getting the lash set right is a bit of an art.

I remember going back into the adjustment process a week or so after initial setting and after re-torque of the head bolts. And typically I find that after setting the lash as carefully as possible there is still a couple loud ones. Then I will choose a feeler of, say, 4 thou or so, and one by one slip that feeler into the gap of each rocker while the motor is idling. I usually find one or two that get quieter when I slip the feeler in. It's a bit tricky as the whole system is pretty noisy with the cover off. But slipping the feeler in and out you can detect a very specific decrease of "click" on a couple of the valves. Note those down and shut off the motor, go back to the sequence of adjustment as in the manual, but without making any adjustments, until you get to the offending valve. Then recheck it. I usually find that the offending one, especially now with the motor fully hot, is slightly looser than I previously thought I set it - the feeler slips in and out easily, almost no drag. So then I'll reset that one, maybe a bit more drag on the feeler than the others, but just slightly. Once I've rechecked and reset any noisy ones, I usually find the whole valve train reasonably quiet.

Tom

 

[WildBill]

It is also quite possible that with grinding cams and lifters and changing out the springs that you should eyeball very carefully your valvetrain geometry to make sure your not experiencing coil bind or that your pushrods are the correct length. This could be viewed with your valve cover off and by watching the springs as the engine is turned over slowly by hand.

When you bought the springs, were they advertised to be the same height as stock? Was any machining needed to install the springs? Did you need to install shims? If any of these answers is yes that could represent a change in the valve train geometry. Definitely the cam grind and the lifter grind would represent a slight change.

William Ramsey
1974 2800 5 Speed Capri
1973 2600 4 Speed Capri
-------------------------------------

I installed Isky valve springs during my SV restoration. I've forgotten the spring pressure, but it's not a huge amount higher than stock.

With resurfaced lifters and lobes on the KB cam, I expected the 1725 to be like-new quiet. Instead, the valve train is noisier than before. The clatter doesn't seem to be confined to any one valve or lifter. Oil seems to be going everywhere it should along the rocker arms.

Is more noise normal with stronger valve springs?

 

[RootesRacer]

When you bought the springs, were they advertised to be the same height as stock? Was any machining needed to install the springs? Did you need to install shims? If any of these answers is yes that could represent a change in the valve train geometry. Definitely the cam grind and the lifter grind would represent a slight change.

William Ramsey
1974 2800 5 Speed Capri
1973 2600 4 Speed Capri
-------------------------------------

Spring shims dont affect the stem to rocker (valve) geometry.
They impact the closing force on the valves as well as increase potential for coil bind, but shimming should not change the sound of the valves unless they are floating at high RPM.

Items that DO change geometry are pushrod length, amount the head is milled (or block decked), valve seat recession, valve length and pedestal height.

 

[WildBill]

A number of items were changed in the setup, springs, grinding a cam, surfacing lifters and a change in lash setup.

My point is that carefully checking the valve train geometry would possibly help determine valve bind isnt happening. A couple of the items changed could change the geometry, removing material from the lifter faces and the cam - could effect geometry via the pushrod. If a spring was purchased that was too short and spacers were employed bind is possible - better safe than sorry I always say.

Personally my money is on the lashup change - but it doesnt hurt to check the geometry since changes were made, unless you can afford to learn through your wallet!

William Ramsey
1974 2800 5 Speed Capri
1973 2600 4 Speed Capri
------------------------------------

Spring shims dont affect the stem to rocker (valve) geometry.
They impact the closing force on the valves as well as increase potential for coil bind, but shimming should not change the sound of the valves unless they are floating at high RPM.

Items that DO change geometry are pushrod length, amount the head is milled (or block decked), valve seat recession, valve length and pedestal height.

 

[RootesRooter]

Definitely no spring bind. I had that happen when I installed an H120 cam years ago. The stock springs bound up and broke two rocker arms and bent half the push-rods.

I had the KB in the car before the restoration. It sounded fine for the first 10,000 miles with stock spirings. I took it off the road four years ago because I started to notice more valve noise after a long trip which turned out to be one badly scored cam lobe. Delta cleaned up the lobe and all the lifter faces at the same time, hence my amazement that it now makes soooo much noise, even after two rounds of lash adjustment (12/14).

I may try the suggested 10/12 settings this weekend. (I had hardened seats installed years ago, so I'm willing to roll the dice per the second-hand advice from Tiger Tom and others.)