TR2/3/3A valve springs

[TFB]

I am assembling my head after a skim and valve job.
I started with an installed h of 1 5/8" ,the previous setting.The 3 spring exhaust had a opening pressure about 75lbs.I was thinking about 95 lbs would be good.Adding even .060 shim didnt change much and it looks like I dont get up to 95/100 until valve is more than 1/2 way open.
So the question is does anyone have any experience with the original or moss triple spring set or other suppliers.Im not sure if I can run the tr4 2 spring set and new retainers with my 3/8 stems.
I really dont get the 3 springs on such a small relatively low rpm valve.
I did run this head previous with these springs and no problem other than grooved ex.valve faces after 20k miles,so maybe im overthinking this.
Thanks
Tom

 

[CJD]

Your shooting way high for stock springs. The engine section of the service manual specifies 71lbs for intake on the seat and 84.5 for exhaust with the 3 springs. The manual also specifies the installed length for each spring, which are different because of the different steps on the valve keepers for each spring.

The 3 springs on the exhaust is so the valve would not hit a single spring resonance and begin bouncing at high speed. High speed in 1953, when these engines were first designed was 5k, not anywhere near the 10k on a modern Vette!

 

[sp53]

I had my tr3 head rebuilt at a shop and they went with 3/8 stems and 2 springs. I have about a 1k on the car and everything seems fine.

steve

 

[TFB]

Thanks Steve.I am checking pressures and installed hieghts with the info in the service manual(Thanks John for that reminder about service manual),and will install the springs I have if things check out.
I figured the 2 springs would work since the top stems are all 5/16.I think the lower retainer on the exhaust gets eliminated.
Thnanks again
Tom

 

[sp53]

Tom over the years when I got heads rebuilt for tr3s I saved everything. This Time I want to it my self, so I will be watching the thread to see how things go, so please keep posting.

Thanks Steve

 

[TFB]

After checking an assembled exhaust valve pressure,and now measuring all free hieghts using the Service manual specs I am going to replace the springs.
Outer springs ranged 1.900-1.940 should be 1.980
So I will probably just replace the triple springs but wish there was a brand name option.Moss is an easy return if they dont measure up.
This a stock cam and I dont want uprated springs.
The only reason I can think of to switch to the daul springs is availability of springs and alloy retainers.
Any thoughts on Moss's triples,duals or other options.
Thanks
Tom

 

[mctriumph]

Spring pressures can cause lifter failure if too high. GET the lifters rockwelled if you plan on
doing anything nutty.I have seen bad batches of lifters sold by good houses. These would NOT have held up to
even 75LBS Byer beware!!
Mad dog

 

[TFB]

Thanks Md.Yes high pressure springs can accelerate cam and lifter wear.And rob horsepower.Not a concern for me.Racing friend once said he wanted the weakest springs possible that worked.Isky list springs but the installed height is1.625 with 100psi installed pressure.I dont think theres room for an installed hieght .065 over stock.Luckily cam and lifters look like new after 24k,so trying to stick to original specs.
I havent been able to get any feedback on the Moss triple springs so Ill just order them tomorrow and check them out.
Tom

 

[TFB]

Thanks Md.Yes high pressure springs can accelerate cam and lifter wear.And rob horsepower.Not a concern for me.Racing friend once said he wanted the weakest springs possible that worked.Isky list springs but the installed height is1.625 with 100psi installed pressure.I dont think theres room for an installed hieght .065 over stock.Luckily cam and lifters look like new after 24k,so trying to stick to original specs.
I havent been able to get any feedback on the Moss triple springs so Ill just order them tomorrow and check them out.
Tom

 

[CJD]

When I rebuilt my engine I had a pile of at least 100 spring sets. I found that very few of those were still up to spec. I found enough for my rebuild, but would have been hard pressed to find many spares out of the pile. I don't think the quality was very impressive, even with the oem springs.

 

[TFB]

Thanks John,I wish I had a pile of used oem to sort thru.(If It was for an Indian I have a drawer full.)
My Moss triple springs came and they are all longer than the specs in service manual.
Outer 2.030 spec 1.980 +50thou.
inner 2.180 spec2.080 +100
Aux ehx. 1.699spec 1.54 +127
I assembled one exhaust valve shimmed .015 to the 1.560 installed hieght.
Opening pressure is 100psi,which is higher than 84 spec.
I asembled ehx.without shims @ 1.575 and get 90psi opening and 140psi @ .400 lit(not sure exact valve opening hieght.)

My thoughts are installing with no shims to give install H 1.575 ,or send back and install the old springs where one is .080 under,but car ran fine.
Or try a set of dual springs.
I wonder if the dual springs are the same without the aux exh.I will have to experiment leaving out the lower aux spring seat and the aux spring.
Thanks Tom

 

[CJD]

I would not worry about the 100lb seat pressure. The difference is not enough to hurt anything, and may help the engine run smoother at the top end. (better valve control)

One thing to test is that there is no coil bind at full open. We don’t have terribly high valve lifts, so it should not be a problem, but the results if it does happen is very bad…so worth taking a few minutes to check on your lowest installed height spring.

 

[sp53]

Thanks you guys for posting the information. How do you measure the spring pressure? Do I need an expensive set up for that?

Thanks Steve

 

[TFB]

Thanks John.I am checking the triple x and dual intakes I got and I think I can get things in the desired range with a liitle more installed height.
The aux exh. spring when installed by itself gave a 10-12 pounds , so even though its .160 or so over length of original spec free lenghth the pressure seems ok.

Steve,I use a method I have used for years on motorcycle cylinders that has proven surprisingly accurate when checked against a more expensive gauge.
I use an old analog bathroom scale on drill press.The old spring scales are better than the junk they sell today.
,Place the scale on the drill table,then the head on the scale.Center the head on the scale and the valve stem to the spindle.Put a spacer,socket etc. over the retainer and lower to contact.Adjust the stop for about .020 travel.Lower the spindle.the weight minus the starting head weight is the open pressure.You really dont even need the stop as you can feel the valve open.Set stop for about .250 and that will be to open pressure.
I usually do motorcycle cylinders and dont have the issue of the outer valves being harder to center on the scale.So for the triumph head I am measuring pressure on valves 3-6,and that will give me enough info to set up 1,2,7&8.
Tom

 

[CJD]

Funny, Tom. I bought a bathroom spring scale from Walmart that went to 350 lbs to do mine. It did double duty…weighing the Wife and me plus the occasional valve jobs for over 25 years. It finally died and was retired.

 

[sp53]

Thanks Tom that is so simple and straight forward that I think I got it. Now I need to find that old scale we got somewhere. I knew I was a pack rat for a good reason.

steve