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SeanF

Valve springs and lower collars

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Hello All,

 

I am re-building my engine which is a 1972 CP unit (in a 1974 CR car). This includes a new standard 150 hp cam (Newman) which is a straight replacement for the old one.

 

I was planning to re-use the double valve springs which appear to be in excellent condition. They have a vertical yellow stripe painted on each spring (see pic from before strip down). Does this signify anything, eg are they some sort of uprated spring and if so should these have been paired with a standard cam? Also they do not have any lower collars or spacers fitted. Is this correct? There was no wear on the head around the guides where the springs sat and the springs appear to have flat polished or hardened ends on the coils.

 

So my questions are:

1. Are these springs OK with standard cam and

2. Is it correct to have no lower collars or spacers.

 

Many thanks in advance for advice.

 

Cheers,

 

Sean

 

 

 

 

 

post-12473-0-66168200-1528326621_thumb.jpg

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Sean,

I think the std springs are red marked so yours are uprated.

I just finished my cp head

I tested and measured my old springs, which were the double springs.

Springrate was according to the BB, but they were 1-2 mm shorter, so this affects closed (seating) force in particular.

I bought a new set of double springs from Chris Wittor, as recommended on here.

They measured ok, although the springrate of the inner springs was slightly lower.

I too do not have shims at the bottom, just the small ring to center the inner springs.

Waldi

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Sean

Which followers are you using for your new camshaft, have just done mine and used the Tuffrided ones, newman recommendation.

Before you put the cam in measure the diameter of the cam journals and compare to the one you take out, I didnt measure mine and have a much reduced oil pressure with only this one item fitted. You will notice that the newman cam has much larger oil grooves in their journals, perhaps that's the issue.

Engine runs much better now as two of the original lobes where much reduced in height + damage to the two followers.

John

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Senior moment, double post

Edited by Waldi

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TriumphTune specified that their uprated springs should NOT have lower spacers or collars, but their catalogue doesn't say what colours they use to ID the springs, if any.

John

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I do not know what the yellow striped springs make them

sports springs but I learned not to do more on the springs

than required on a TR6.

So I left them out and took the red ones.

 

The inner springs of the yellow set are a bit longer,

amount of windings and wire diametre is the same

on small and big compared to the red ones.

 

So I would say if they are already fitted I would let them work.

 

If I buy new ones I would take the red ones because they did

their job in my TR6 engine with sports cam pretty well.

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Thank you all for the replies. I think I will refit what I have got using the "if it aint broke" concept. Currently absorbed in degreeing the new cam with a new chain and new sprocket wheels. Great fun...not.

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Hi Sean,

as was told to me (just in time) if you need to relate to #1 iNLET valve make sure that is what you are doing.

 

On my 4A I set up on #1 valve which just happened t be the exhaust - oops!!!

 

Roger

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Thanks Roger.

 

Yes I think I managed to get that one OK.

 

After much head scratching I managed to get it timed yesterday. The peak of the intake lobe should be at 105 degrees ATDC and I managed to get mine to 106 so I am calling that good. I've been trying to verify this by checking for equal lift on the intake and exhaust at TDC but I'm afraid I cant quite get my head around that one. I'll have one more go today and then give up gracefully.

 

Exciting times. I picked up my newly refurbed gearbox and overdrive from Bill at Hardy Engineering on Friday so hopefully I will be fitting engine and GB to chassis before the end of the week. Then its body back on!

 

Cheers,

 

Sean

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Hi Sean,

if you have the 'timing angle# for the cam then you shouldn't need to check for equal lift.

 

TRy and imagine what you would do if it was different :o:o:(

 

Roger

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