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Discussion Starter #1
Well, the big day has arrived, and I am now swapping on my Edelbrock heads for my cast iron ones. I bought this pair of heads back in 06, while I was in Germany, at Stuttgart.
So my problem is, that the aluminum heads have springs that came with the heads. They are not the same height as the springs that came off the iron heads. The valves are the same over all length, and the measurement from the spring seat to the valve locks is the same as well.
So, as all the other measurements are the same, is my best bet to machine into the aluminum heads to ensure I retain the correct installed spring height?

Is there any reason to think that the springs that came on the aluminum heads are designed for the softer material, and there for meet the same requirement, even though they are longer over all?

The only thing I didn't compare was the installed height of the Eddy springs on the iron head.... I can get pictures if you think it might help. Of course cost is a concern, and I was hoping to be able to use the springs off the iron heads, in order to maintain the correct valve train geometry...
 

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Probably will need new springs....you need to watch seat pressure/compressed height (based on your cam )to avoid spring bind --- which should be spelled out in the docs with your heads. Also double check your valve/piston clearance with heads bolted/torqued to specs. A few sets of head gaskets is best for getting it nailed down. Pics won't help much - you will need a dial indicator with a mag base to measure it though. HF has them cheap enough....I think you can find plenty of how to vids out there. Let us know it goes....
 

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I leave the head gaskets off for checking piston to valve clearence unless the pistons are out of the hole. I throw some fudge factor in there. felpro gasket compressed .038" also buy a couple solid lifters to check piston to valve.
 

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Discussion Starter #5
I don't have the correct valve spring height measuring tool to get you the correct measurement. But, an eye ball is almost a quarter of an inch.
My buddy says that they should be fine, as the springs are softer, yet shimmed for the aluminum. I say BS, the springs that came off the iron heads should go on the aluminum heads. The only difference is the steel cup, that goes under the springs on the aluminum heads. It is .080 of an inch....
The other distances are all the same.
 

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Set the spring height of the springs specified by the cam card. If the installed height is more than specified then the springs can be shimmed. If the installed height is less, offset retainers or locks are available.

A spring cup or at least a steel shim should be used to keep springs from digging into the aluminum spring seats.

A set of snap (telescoping) gauges, a dial indicator and a valve spring compressor are the tools needed to set installed height.

Eyeball and guessing is a sure-fire method of putting a valve in the oil pan.
 

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Discussion Starter #7
Art, you are right. I have been down this valve train path before, and that is why I am asking now. The springs that came on the aluminum heads has that offset retainer. I know that summit sells a dial indicator for valve springs,
http://www.summitracing.com/search/?keyword=cca-4928&dds=1

I am just trying to make sure my thinking is straight, and how much is it going to cost me to keep things the same!
 

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Discussion Starter #8
Heads at the machine shop...
 

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Set the spring height of the springs specified by the cam card. If the installed height is more than specified then the springs can be shimmed. If the installed height is less, offset retainers or locks are available.

A spring cup or at least a steel shim should be used to keep springs from digging into the aluminum spring seats.

A set of snap (telescoping) gauges, a dial indicator and a valve spring compressor are the tools needed to set installed height.

Eyeball and guessing is a sure-fire method of putting a valve in the oil pan.
Meant dial calipers instead of dial indicator.
 

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Discussion Starter #11
I've already had to put two cams, three sets of pushrods, and two sets of roller rockers on this stupid motor. I don't have the valve spring tool, that shows you when a coil will bind, or what the open and closed spring pressures are. As I recall, the machine shop (different one, long story) had to install longer valves to hit the numbers, the last time I went through this. I was concerned that I would have to get longer valves, but I hadn't thought about the spring cup on the aluminum heads.
Regretfully, sometimes you have to take stuff to somebody that does this for a living. I will report back when I get the heads and a plan...
 

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Discussion Starter #12
Update:
As of today, the springs that were on the aluminum heads were for a roller cammed engine, and would have wiped out my poor hydraulic camshaft. The springs on my iron heads, that I thought were 'correct', were only half right, and I was within .010 of failure at specified height. This was evidenced by the bent stud in the head....
The new machine shop gives me waaaaaaay so much gooder vibes than what I got from my last experience. A new set of springs are on order for the aluminum heads, and I will report when the exercise is over!
 

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Your valve springs need to match the camshaft profile regardless of what cyl heads your running. The cam manufacture can tell you what the opening and closed load should be. Install a valve with the keys and spring retainer. Use a dial idicator and measure from the cyl head spring cup to the top of the retainer and then minus the retainer thickness will give you the closed height. To get open spring height go by the cam lift x rocker arm ratio will give you valve open lift at the valve tip. Them take the closed height minus the the valve lift at the valve tip will give you the valve open height. Once you have the two number then the springs need to go to the machine shop and be check at those heights on a spring checker to get the loads of the the valve springs at the two given heights. All valves springs should be check this way. You would be shock that most advertised and actual valve spring loads can be very different as manufacturing tolerances for spring aren't very good especially for the aftermarket.
 

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Discussion Starter #15
I went to these guys,

http://www.meridianautocare.com/machine-shop.php

Very clean shop, very meticulous work. I get a very good consumer vibe from them! The guy that I have been dealing with, explained the spring problem to me the same way. They get lots of springs either new in the box, or off of factory heads, that don't meet the companies own specifications. I should pick up the heads on Friday, and they will be able to tell me everything that I have. What the springs bind at, open and closed seat pressure, everything! I really do feel good about this place!
 

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Yeah - sounds like they got you under control. I can personally atttest to the fact that springs have a high degree of varaiability - brand does not matter. ALWAYS - ALWAYS - ALWAYS test them prior to install. Anything more than 10% out of tolllerance should be replaced IMO....
 

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Judging from the shop pictures it looks like you went to the right place! They have some big money invested into some of the machine centers. The valve seat and guide cutter they have is top of the line! If they have good personal running the machines I think your in good hands.
 

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What Brian said, you don't see many shops that clean, organized and with that caliber of equipment!
 

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Looks like a good facility, I think you made a good decision. Lots of stuff to check and confirm when it comes to heads and valvetrain, most of engine "blow up's" are from broken valvetrain parts. Not the place to cut costs or use questionable parts.

Be sure to use a good break in additive or break in oil designed for flat-tappet cams.
 

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Discussion Starter #20 (Edited)
Well, I picked up the heads Friday right at closing time. COMPLAINT: When you and I agree on "around a hundred and a half", what does that mean to you all here?
At Meridian automotive, it means the bill will be 280.00.
Other than that, the new springs are installed. I did a P2V check with playdough, and had a mile with the new 2.02/1.90 heads, and the valve stem wear was nice and skinny,right in the middle. So, we are working on the brake assembly, and the heads will be back on the car and the whole thing wrapped up, hopefully, by the end of the week!-) More pics to follow in case you didn't catch my 'update' pictures a few days ago....
 
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