Aluminum Head Set-up Questions

[70rcode]

What is correct way to set V-spring instal height on new Bare Mp Hemi head ? The typical 0.060" thick spring cup/locater is causing my v-spring height too short issues..Planning to use new Manley valves..Thx for any info,...tom.

 

[493 Mike]

Machine the spring seats deeper.
Mike

 

[IQ52]

Machine the spring seats deeper.
Mike

Could be done. Not the first thing I would do. I would require a lot more information about the combination before I would hazard a recommendation.

 

[RemCharger]

I had use a combination of + .050 keepers and +.050 retainers to get mine worked out. In your case is there a thinner cup to start with?
Give IQ52 some more info!

 

[Fran Blacker]

A small butt in. What valve seals would you use on these heads ? To minimumize retainer to guide interference and some oil to guides?

 

[IQ52]

I had use a combination of + .050 keepers and +.050 retainers to get mine worked out. In your case is there a thinner cup to start with?
Give IQ52 some more info!

See.......already a potential solution or two that are far less invasive.

I like the quoted post except for the part about giving me more information. I don't really want to make the decision on what to do with these heads.

Remember......you have got to be smarter than your cylinder heads.

 

[70rcode]

Planning to use a standard 0.500" dia tap down on Viton valve stem seal unless someone knows better.

 

[70rcode]

Would it be asking too much for a factory spec engineer (or factory tech) to Know a spring cup is ALways used with alum heads & just factory mill the spring seat correctly to start with ? They're around 0.050" thick & i don't know Anything about alum cylinder head design..

 

[70rcode]

Hmm...+.050" keeper & + .050" locks sounds like good math to get taller V-spring install height fix as that Seems like its moving the retainer Away from spring seat & i need more separation didtance ?

 

[IQ52]

Let me quote you..........

i don't know Anything about alum cylinder head design..

And yet you presume that the factory machined the spring pockets incorrectly?

The spring pocket thickness is a critical area when porting a cylinder head. I've seen some substantial airflow gains in intake ports when working that area in conjunction with other areas. That information, with the fact that I've taken cylinder heads to .800" lift with never cutting the spring pocket at all, tells me I ain't gonna start whacking on the spring pockets as a first priority.

 

[69Bee]

How about 0.100" taller valves...

 

[IQ52]

How about 0.100" taller valves...

That is something that could work.........if it doesn't make the rocker arm unhappy. You gotta think these thing through.

 

[69Bee]

That is something that could work.........if it doesn't make the rocker arm unhappy. You gotta think these thing through.

Because they don't sell 0.100" taller valves... You can compensate with longer push rods, as long as you don't run out of stud length.

 

[IQ52]

Because they don't sell 0.100" taller valves... You can compensate with longer push rods, as long as you don't run out of stud length.

You can have valves made as long as you want.

Think some more.

What stud are we talking about?

On a hemi the longer you make the valve the farther the valve tip moves towards the tip of the rocker. And the higher you raise the rocker shaft/fulcrum the worse it gets also. Taller/longer valves may result in the need to design a different rocker or move the shaft up & towards the valve tip. Then do you have to move the push rod holes in the cylinder head? Does that then require grinding on the block?

 

[Fran Blacker]

The spring height is .050 to short. If you did nothing would you have coil bind or would retainer hit valve stem seal? If neither of these happen what's wrong with running as is? Damage from to much spring pressure or shorter spring life? I'm wondering about that, thinking of buying a pair my self.

 

[69Bee]

You can have valves made as long as you want.

Think some more.

What stud are we talking about?

On a hemi the longer you make the valve the farther the valve tip moves towards the tip of the rocker. And the higher you raise the rocker shaft/fulcrum the worse it gets also. Taller/longer valves may result in the need to design a different rocker or move the shaft up & towards the valve tip. Then do you have to move the push rod holes in the cylinder head? Does that then require grinding on the block?

Sorry, I am used to dealing with chebbies mostly at work (rocker stud). I digress...

 

[70rcode]

Was tryn 2 avoid disturbing the valve train geometry as i Do have good V-stem/rocker contact pattern @ 0.600" net lift & 1.86" instl height & my rockers are already runnin close to retainers, & + .050 retainer/locks Could agrivate that to actual rocker-retainer contact = Bad...Maybe i can source some 1.80" instl ht springs & just machine "tag" the spring seat as No port roof grinding is planned.How much spring seat depth milling can i safely do ? These advertized direct oem iron interchangeable alum heads don't seem exactly "bolt on" ready to use with spring cups & factory 1.86" spring height hardware & i sure can't afford to over thin mess up a new pair of heads !!

 

[451Mopar]

On the MW Victor heads we have PAC Racing Springs (#1326), and PAC custom machined the valve seats inside locator (not cup style) from the standard 0.060" to 0.030" thick.
Also had +0.100" retainers, and I think +0.050" locks too.
That did cause the retainer to just touch the underside radius of the rocker arms. We used a 0.060 lash cap on the end of the valve stem to get the clearance back.
We machined off the factory rocker stands, and used the Max Wedge style Rocker stand blocks so we could set the rocker shafts at the correct height.
Originally, I tried cutting the valve seat in the head down, but just barely broke through into the top of the exhaust port.

 

[70rcode]

Thx, 451M, 4 all that info...sounds like you really worked those heads over short of meltin 'em down & diy recasting ! I really like the custom PAC machined id locator base flat down to .030" (1/2 thickness) deal.

 

[70rcode]

Does anyone Know if the 1st g2 alum head ( '65 A990 race packge) even used Any steel flats under the springs other than a few std thin steel spring shims ?? Of the dozen magazine articles & the original A990 service bulletin, i dont remember any steel protective disc ever mentioned 4 the aluminum SS race heads !!