360 Magnum springs

[sledger46]

I recently purchased a used 320 HP, 360 Magnum crate engine. I am trying to determine what valve springs are on the heads. The springs on the heads do not look conical to me at all.

Here is a LA 360 "J" head with .500" lift springs for comparison to the Magnum head below:

360 Magnum head:

Based on some research the later 320HP crate engines came with the big valve RT heads with heavy duty springs. I am guessing they are the MP .525 lift springs. Anyone familiar with the RT heads or MP springs?

 

[66dartgt]

Off the top of my head these look like the 340 type springs which are good to around .500 lift. If you pull a couple springs off the heads - take them into your favorite machine shop and have them measure the open and closed pressures. Thats the best way to find out what they are.

 

[sledger46]

The top (first) picture was of a "J" head with .500" lift springs for comparison. I fixed the labels on the pictures so hopefully it is clearer.

 

[UOP]

I run the .525" lift springs in my magnum. Looks the same, but that doesn't mean anything.

 

[sledger46]

I run the .525" lift springs in my magnum. Looks the same, but that doesn't mean anything.

On the bright side, I won't have to hunt down retainers for MP .600" lift springs ;-). How do you like your Comp XR265HR camshaft? I contacted Comp for recommendation and they cam back with 230/236 .050, 110 LCA and .577" lift. Seems a bit over kill for stock Magnum heads.

 

[UOP]

On the bright side, I won't have to hunt down retainers for MP .600" lift springs ;-). How do you like your Comp XR265HR camshaft? I contacted Comp for recommendation and they cam back with 230/236 .050, 110 LCA and .577" lift. Seems a bit over kill for stock Magnum heads.

It's not the right cam for my combo. It was spec'd by Comp because I told them I was going to hang a turbo on this motor. It's a mild mannered cam and would be better suited for a daily driver.

I agree, that is overkill for the heads since they peak before .500" lift. I asked them to spec a cam for me later on and they cam back with 231/234, .534"/.531",112. My engine is 100% stock other than the induction and valve train. I don't know if it would have worked or not since I never bought it.

 

[sledger46]

I am working with Comp on a custom cam. I grabbed lobes for Ford 302/351 since they are already on 1.6 ratio rockers. Right now I am planning on 224/230 @.050 with .513" lift to use the .525 lift springs. I found another intake lobe that would make a 230/230 @.050 with .513" lift as well.

 

[Abodybomber]

Both good choices.Good idea,on the Ford Lobes,been looking at the Viper grinds,for lobe choices.

 

[bad440]

Both good choices.Good idea,on the Ford Lobes,been looking at the Viper grinds,for lobe choices.

???????????really

 

[Abodybomber]

Really..... RHS/EQ heads,peak .525/.550 ish, unless absolutely insane..Stock castings,.470/480,on really clean castings. The magic number ,seems to be 224 to 234@ .050,for a stock bottom end. The H.P/ RPM ,is there ,if you want it.....