Cutting valve spring seats.

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dgibby

dgibby

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Anybody cut your own seats? The comp cams cutter that goes on a drill was what I was looking at, but no sure if its worth doing myself or take them to a machine shop. Over $100 bucks for the cutters for one time use might not be worth it but thought I would try to get some feedback. Thanks.
 
Double springs. Thinking about a cam upgrade and just about any comp cam above the XE268 require a double spring.
 
It can be done. Use a good drill with a t handle and go slow. Its not the best way to do it, but in a pinch it can be done. If you have any droughts at all, dont do it, take it to a shop.
 
I had a machine shop do it one time and when I went to fill the radiator to start the engine, I could never get the radiator topped off! Turns out the spring seats were cut too deep and the bottom of the valve spring punched a hole right through the cylinder head and into the water jacket. In other words, there is a limit on how far you can go. This was a stock 1965 273 motor.
 
Simple procedure, but like Mike said, go slow and be careful. Also don't cut the seats deeper. Only cut them for a larger diameter spring. The head in that area is very thin in relation to the water jacket. You do NOT want to cut them deeper.
 
MRL Performance said:
It can be done. Use a good drill with a t handle and go slow. Its not the best way to do it, but in a pinch it can be done. If you have any droughts at all, dont do it, take it to a shop.
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No doubts about doing it but seems like it might not be worth the risk. Funny how they make it look like you just pop the tool in your drill and go for it.
 
dgibby said:
No doubts about doing it but seems like it might not be worth the risk. Funny how they make it look like you just pop the tool in your drill and go for it.
Click to expand...

Actually, that's just how it's done. As long as you're careful, you'll have no problems.
 
So you buy $100 the tool, try it yourself, break through the casting, and have to buy new heads....

Then have to get the new heads freshened up....


What have you got to loose???
 
It's not the cutter, but the drill that's the wild card. Use a drill press, or have a shop do them. It won't be much more than the price of the tool...
 
krazykuda said:
So you buy $100 the tool, try it yourself, break through the casting, and have to buy new heads....

Then have to get the new heads freshened up....


What have you got to loose???[/QUO


I could skip the tool and drilling b.s and go straight to the new heads since that would be my preference, but then there is the money issue...bummer

Guess I'll get some machine shop quotes.
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With limited machining skills using this set-up I would be thinking about using spring cups, they would "take up some slack" of not having to cut down as far in order to get a good clean cut all the way around.
Well hell this was sounding like a good thing till I thought about having to shim if needed then the shims go under the cups LOL....hmmm might still work out good.
 
I get the feeling this is to fit dual spring assemblies - not to allow for taller installed heights. So a cup won't do much. You have to remove the top of the guide and the inner step of the spring seat. I've always had those operations done whenever a set of heads get s valve job. At least then it's done if you want to run something more aggressive later.
 
A drill press is nice, but not necessary. The cutting tool's pilot is the same size as the valve guide, so you cannot tilt the tool. It stays on center in the guide. I've done literally hundreds using a hand held cordless drill. It's very easy to see when the job is done. As long as you don't have your face hangin out, you won't mess it up.

If you shop around, you can get whichever tool and arbor for right around 50 bucks.
 
Check to see if a beehive spring is available for your cam selection and just cut the guide down. You should be able to get a 1.7 installed spring height setup with a +.050 valve lock.
 
I was wondering about Bee Hive springs also. What I am putting in my 400

How much lift before you have to cut your guides down?
 
mderoy340 said:
OEM head tolerance are all over the place so you need to measure every retainer to guide. No telling how many valve jobs have been done in 40+ years. .480 normally is safe on a j head but you need to measure.

Comp Cam 1.7" installed height beehive spring and retainer included in premium option kit for XE274 and up.
http://www.summitracing.com/parts/cca-26995-16
http://www.summitracing.com/parts/cca-795-16
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What he said ^^^^^

There's no hard and fast rule about when to cut guides. You simply have to mock up the valves in the heads minus the springs and measure. There's no other way to be certain.
 
What size cutter and seals are needed? I get the 3/8 arbor, but the cutter and seals are different sizes. Is the .530 the correct cutter for the heads?
 
gliderider06 said:
What size cutter and seals are needed? I get the 3/8 arbor, but the cutter and seals are different sizes. Is the .530 the correct cutter for the heads?
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That's totally dependent on which springs you use. There are several different sizes. You should make that determination based off the spring's ID and OD and from the measurement between the guide and retainer.
 
I did this on a couple sets of our heads and it is as easy as it looks in the videos.

The first time was a bit scary but after a couple of cuts you'll feel like a pro.
 
RustyRatRod said:
That's totally dependent on which springs you use. There are several different sizes. You should make that determination based off the spring's ID and OD and from the measurement between the guide and retainer.
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RRR correct on spring seat cutting. Spring seat cutter selected depending on spring ID/OD. I was only talking about guide cutting to increase valve seal to retainer clearance.
 
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