Which valves/springs for my 360?

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'66Cuda

'66Cuda

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I am doing a home port and polish on my 915 1.88 J heads. I am going to go with larger 2.02 intakes and am going to replace the exhaust valves. I am not sure of the cam specs, as these heads are going on a motor that only has 3-4k on a rebuild, but has smog heads. The previous owner told me that it was not a giant cam as he wanted a good street machine. So in order to buy new valves and springs, what do I need to look out for? I was thinking Stainless valves (Milodons?) but some are different lengths. Also what would be a good spring? It is going in a '66 Barracuda with a 727, 3.55 geared 8 3/4 rear end.

Thanks!
 
Hard to recommend a spring without the cam specs. Pokin' and hopin' probably isn't a good idea.

See if you can find out what cam is in there. If the PO rebuilt it, he should know. Springs need to be properly matched to the cam.
 
The previous owner doesn't remember what he put in it. It was rebuilt about 10 years ago and he couldn't find the cam card. He said it was a Crane, and that it was a mild cam. I know springs go with cams, but didn't know if there was a rule of thumb with stock cams vs mild cams vs wild cams? I may just have to buy a new cam and springs. The valves I need to order this weekend.

Thanks!
 
Well, you "might" be able to use a dial indicator and figure out the lift, and then compare to some older Crane cam profiles and get close I guess. I don't know if there are any numbers on the end that would help ID it or not.

It would concern me though, not knowing what's in there and guessing. It could bite ya in the long run, er short run whichever comes first.

Where are the springs that were on it?
 
crane cams usually have info etched on the front of them.....
 
If you don't know and don't want to tear the front cover off to get a cam number, Comp Cams #901's are a safe bet for most mild cams. tmm
 
toolmanmike said:
If you don't know and don't want to tear the front cover off to get a cam number, Comp Cams #901's are a safe bet for most mild cams. tmm
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I would agree, the 901-16's probably. The problem is the PO says it's a mild cam. One mans mild, might be different from another mans mild.
 
This not unimportant to the health of your engine. Dial indicators are cheap. Buy one and measure the lift. Then you can choose an appropriate spring.
 
So if I just order some small block valves, will they work? Do I need to pay attention to the overall lengths and such?
 
RustyRatRod said:
This not unimportant to the health of your engine. Dial indicators are cheap. Buy one and measure the lift. Then you can choose an appropriate spring.
Click to expand...

I already have a couple and a magnetic base. I may try it.

Thanks
 
Do you have a valve/seat grinder available? Please don't just order valves and stick them in. It sounds like you need to make friends with a machine shop and get your check book out.
 
I was going to order the valves and then take them, along with the heads, to the machine shop. I can't cut the new 2.02's in myself. I have never heard of just ordering valves and sticking them in!
 
I suggest letting the shop that's doing your heads order them that way you won't be stuck with a set of valves you can't use in case you don't get the correct ones. As for the valve springs, I'd measure the lobe lift to see what it exactly is before I bought any springs.
 
'66Cuda said:
I was going to order the valves and then take them, along with the heads, to the machine shop. I can't cut the new 2.02's in myself. I have never heard of just ordering valves and sticking them in!
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Sorry, The direction the thread was going I didn't know how much you know. We get a lot of beginners here that can be led the wrong way. tmm
 
Just a thought,did the previous owner change the valve springs when he put the camshaft in...maybe able to re use the springs if they are the ones for your cam,off of the old heads,
 
TMM- I get it. I do appreciate your advice. Admittedly, this IS my first time reworking heads like this. My thought was to get the parts I wanted and take them to the machine shop, so I know what I am getting.

I have thought of taking the valve springs from the smog heads and putting them in my J heads. I just wasn't sure that he had replaced those along with the cam. I may just have to drop them off bare and let the machinist do his thing. I am sure it will make him happier. In that case are the expensive valves worth it on a mostly street 350-375 hp application?

Thanks
 
'66Cuda said:
I have thought of taking the valve springs from the smog heads and putting them in my J heads. I just wasn't sure that he had replaced those along with the cam. I may just have to drop them off bare and let the machinist do his thing. I am sure it will make him happier. In that case are the expensive valves worth it on a mostly street 350-375 hp application?

Thanks
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I'm shooting for just a tad more than that on my 360 build, and I'm staying with the 1.88/1.60's in my 915 heads.
 
'66Cuda said:
TMM- I get it. I do appreciate your advice. Admittedly, this IS my first time reworking heads like this. My thought was to get the parts I wanted and take them to the machine shop, so I know what I am getting.

I have thought of taking the valve springs from the smog heads and putting them in my J heads. I just wasn't sure that he had replaced those along with the cam. I may just have to drop them off bare and let the machinist do his thing. I am sure it will make him happier. In that case are the expensive valves worth it on a mostly street 350-375 hp application?

Thanks
Click to expand...

All the stock springs I've seen on 70's smog heads were a fairly small diameter. Most standard design aftermarket springs are in the area of 1.43" o.d. or larger. You can also verify if their correct (and good) by testing them. If you don't want to buy a spring pressure tester your machinist should be able to do it for you.

Good designed valves can aid in air flow. I learned that several yrs back when I swapped stock valves for a set of REV valves in a set of X heads. The numbers jumped up 15-20 cfm across the board without doing anything else. They also lowered the chamber volume 4 cc's which raised the compression ratio. For 350-375 hp you don't need 2.02 valves if the bowls and ports are prepped right. Since you say this is your first go around read up real good on what works and what doesn't so you don't do a bunch of work and end up with a pair of boat anchors. I have seen guys do that. A pretty port doesn't always mean an efficient port.
 
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