Checking valve spring heights.

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prorac1

prorac1

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Engine - 1983 318, stock heads, rotator style exhaust retainers (replaced with some used intake retainers).

Camshaft - 214/224 @.050, .444/.466 112 LSA, 108 ICL, installed at 104 ICL.

Installed height for new springs is 1.65

Measured seat to retainer height on one head. Here's our findings.

IMG_3527.JPG


As you can see, the intakes are almost perfect.

But, because the lock grooves are lower on the valves, the exhaust installed heights are WAY lower than installed height spec.

Is this going to be a problem? Obviously the at seat spring pressure will be higher.

Haven't been able to check coil bind or retainer to guide/seal clerance.

Thoughts? Thanks. Eric and Jason.
 
prorac1 said:
Engine - 1983 318, stock heads, rotator style exhaust retainers (replaced with some used intake retainers).

Camshaft - 214/224 @.050, .444/.466 112 LSA, 108 ICL, installed at 104 ICL.

Installed height for new springs is 1.65

Measured seat to retainer height on one head. Here's our findings.

View attachment 1715132861

As you can see, the intakes are almost perfect.

But, because the lock grooves are lower on the valves, the exhaust installed heights are WAY lower than installed height spec.

Is this going to be a problem? Obviously the at seat spring pressure will be higher.

Haven't been able to check coil bind or retainer to guide/seal clerance.

Thoughts? Thanks. Eric and Jason.
Click to expand...
When it comes to springs.....050 is one thing, but what you need to know is the spring psi at those heights before you slap it together. At .080 or almost .100...It could be 40+lb diff with a double spring and could hurt something on break in...or use it up and coil bind at max lift.

1st off, which spring is this?
901 comp? Probably at 130 @1.60... should be okay.
 
Last edited:
prorac1 said:
Engine - 1983 318, stock heads, rotator style exhaust retainers (replaced with some used intake retainers).

Camshaft - 214/224 @.050, .444/.466 112 LSA, 108 ICL, installed at 104 ICL.

Installed height for new springs is 1.65

Measured seat to retainer height on one head. Here's our findings.

View attachment 1715132861

As you can see, the intakes are almost perfect.

But, because the lock grooves are lower on the valves, the exhaust installed heights are WAY lower than installed height spec.

Is this going to be a problem? Obviously the at seat spring pressure will be higher.

Haven't been able to check coil bind or retainer to guide/seal clerance.

Thoughts? Thanks. Eric and Jason.
Click to expand...


How many grooves are in the valves. You can use some locks that give you .050 more installed height.

You also need to check the stem height and see where those are at.
 
The springs are Elgin "901" springs.

I'm told they are the same spring as a Comp 901. Specs are identical
 
I always buy 8 regular exhaust valves and get a valve job done when removing rotators off a head. You can then buy a pack of .015 and .030 spring shims to even the spring heights.
 
2 grooves per valve. Both intake and exhaust.

As you can see the exhaust valve grooves are lower on the stem than the intake. Hence the installed height difference in my opinion.


IMG_3528.PNG
 
Where would a fella even start to find those locks?

Are they application specific or by size?
 
What kind of shape are the exhaust valves in? You may need to replace them anyway. If that's the case, you can just get the longer valves. Rock auto has engine tech exhaust valves for about $25 for 8.
 
mopowers said:
What kind of shape are the exhaust valves in? You may need to replace them anyway. If that's the case, you can just get the longer valves. Rock auto has engine tech exhaust valves for about $25 for 8.
Click to expand...

They are a little rough. What year valve would I look for? Like 1973 ish?

It would be a total hack job. Lol. Hand lap and cross fingers. Lol
 
The +50 installed height stuff from Comp is only available in the 10* Super lock, in single groove form for a 3/8 stem. Pioneer offers 7* locks in single grove. But this is useless info. Your not going to find a 2 grove offset keeper. ^^^^ mopowers said, get new 4 grove valves and the keepers to go with The 4 grove exhaust.
 
Looks like the rotator valves were 2 groove and the non rotator were 4 groove.
 
Max1196 said:
The +50 installed height stuff from Comp is only available in the 10* Super lock, in single groove form for a 3/8 stem. Pioneer offers 7* locks in single grove. But this is useless info. Your not going to find a 2 grove offset keeper. ^^^^ mopowers said, get new 4 grove valves and the keepers to go with The 4 grove exhaust.
Click to expand...

Thank you. We posted at the same time. Lol. Sounds like that's what we're going to do.

Think there's a chance in hell that a hand lap will get em to seal.

Thanks again. Eric
 
I have gotten some pretty grody lookin valves to lap in before. Never know till you try.

prorac1 said:
Thank you. We posted at the same time. Lol. Sounds like that's what we're going to do.

Think there's a chance in hell that a hand lap will get em to seal.

Thanks again. Eric
Click to expand...
 
Shims wouldn't change the spring height would it? Unless springs are so weak they are sloppy? Just asking...and still learning lol
mderoy340 said:
I always buy 8 regular exhaust valves and get a valve job done when removing rotators off a head. You can then buy a pack of .015 and .030 spring shims to even the spring heights.
Click to expand...
OP, did you check the installed height with springs removed?
 
prorac1 said:
They are a little rough. What year valve would I look for? Like 1973 ish?

It would be a total hack job. Lol. Hand lap and cross fingers. Lol
Click to expand...

Mic the valve stems too. They may be pretty worn.

Enginetech V1589 are good replacement valves and pretty inexpensive. As stated, you'd just need a set of 4 groove keepers to use with them. Sounds like you've already got retainers covered.
 
4spdragtop said:
Shims wouldn't change the spring height would it? Unless springs are so weak they are sloppy? Just asking...and still learning lol

OP, did you check the installed height with springs removed?
Click to expand...

You can only shim the spring if the installed measured height is to tall.

My intake valves height is almost perfect.

The exhaust, because of the rotator style grooves, are far to short.

Measured without spring
 
mopowers said:
Mic the valve stems too. They may be pretty worn.

Enginetech V1589 are good replacement valves and pretty inexpensive. As stated, you'd just need a set of 4 groove keepers to use with them. Sounds like you've already got retainers covered.
Click to expand...

I can tell from thecwiggle test that the old exhaust valves have a little slop. Nothing horrible. But not great.

Our plan is to run these heads for a year or two and than get another set of heads, teach jason how to port heads, and get a valve job, and guides if needed.

But it looks like we will only have $50 into replacing the valves and locks
 
Better a little loose, IMO than too tight.

prorac1 said:
I can tell from thecwiggle test that the old exhaust valves have a little slop. Nothing horrible. But not great.

Our plan is to run these heads for a year or two and than get another set of heads, teach jason how to port heads, and get a valve job, and guides if needed.

But it looks like we will only have $50 into replacing the valves and locks
Click to expand...
 
That was my line of thinking, but wasn't sure, shims bring up spring psi.

prorac1 said:
You can only shim the spring if the installed measured height is to tall.

My intake valves height is almost perfect.

The exhaust, because of the rotator style grooves, are far to short.

Measured without spring
Click to expand...
 
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