Magnum timing chain with LA timing cover, and fuel pump eccentric

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prorac1

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we are building a new engine for Jasons @Prorac2 63 valiant.

The block is a 1994 magnum 360. With LA cylinder head oiling provisions.

We are using the factory crank and rods and a set of weisco pistons.

For heads we are running edelbrock performer rpm aluminum heads.

Obviously we’re running a roller cam. We’re retaining the mechanical fuel pump for simplicity, along with the LA accessory drive.

Here’s the question.

We are looking for a good billet double roller adjustable timing chain. I’m reading that the LA and magnum use different timing chains.

Would like an adjustable timing set for degree in the cam.

But all I can find are non adjustable cheapies.

What’s everyone running on their magnums.

Thanks. Eric and Jason.
 
I just put an LA T-chain on a mag block I am building this week. It is an early one too with the rocker oil holes. Same thing is in my middle son's magnum in his truck. Both motors used long snout cams.
 
LA and magnums use different timing chains?

The reason we’re asking is because we saw this on an advertisement for a roll master timing chain. And it made us question it.

BA41F1B5-9076-4817-B669-B40B048A2AAD.png
 
That was our thoughts as well. That’s why I figured we would ask you guys what your experience was.
Well like you I have seen a lot of typos especially on sites like Summit or Jegs.
Spring specs for instance, all over the place. Mic the crank snout
 
The reason we’re asking is because we saw this on an advertisement for a roll master timing chain. And it made us question it.

View attachment 1715588826

I have never heard of that before...

Can you measure the crank? I am not sure if the magnums I mentioned had a magnum or LA crank, The cranks came from my stash in the shop.The one I am building now's original crank had issues where the main seal rides. I do have that crank out there and will check if an LA gear works on it tomorrow.
 
OK, for what it's worth, I just got off the couch and went out to the shop. I used an old double roller gear and it fit on a 360 magnum crank and 3 360 LA cranks. It also fit a 318 magnum crank. Your results may vary.... but I doubt it,
 
OK, for what it's worth, I just got off the couch and went out to the shop. I used an old double roller gear and it fit on a 360 magnum crank and 3 360 LA cranks. It also fit a 318 magnum crank. Your results may vary.... but I doubt it,

Awesome! Thank you very very much sir. We greatly appreciate it.
 
Awesome! Thank you very very much sir. We greatly appreciate it.

Well. I hope I don't steer you wrong, but that is the best info I can give with the cranks I have here. I honestly never heard of a difference before.
 
OK, for what it's worth, I just got off the couch and went out to the shop. I used an old double roller gear and it fit on a 360 magnum crank and 3 360 LA cranks. It also fit a 318 magnum crank. Your results may vary.... but I doubt it,

Awesome! Thank you very very much sir. We greatly appreciate it.
Same chain set for LA's and Magnum's. You're good.
 
Well FWIW, Summit lists several timing sets for the Magnum separately from the LA, so SOMETHING is different.
 
Well. I hope I don't steer you wrong, but that is the best info I can give with the cranks I have here. I honestly never heard of a difference before.

No worries brother. I’m going to have the machine shop Mic the crank for the magnum and we will compare findings.
 
No worries brother. I’m going to have the machine shop Mic the crank for the magnum and we will compare findings.
I should have taken my cheaters out with me and I could have mic'd them.

Well FWIW, Summit lists several timing sets for the Magnum separately from the LA, so SOMETHING is different.

I wonder if it has anything to do with the tensioners on the magnums?
 
I should have taken my cheaters out with me and I could have mic'd them.



I wonder if it has anything to do with the tensioners on the magnums?

It just might. I was also thinking maybe it had something to do with the timing covers.....they ARE different.
 
This is what I am running in my 1993 magnum with LA style Trick Flow heads. It's a Cloyes Street True Roller with 9 degreeing slots. According the Cloyes the difference between the LA and Magnum sets is that LA set is the camshaft sprocket is balanced to work with a fuel pump eccentric. See the picture below that might help. I am not using the eccentric, but put it in to get the correct spacing since my cam is a LA based long nose cam.
Cloyes Street Billet True Roller Timing Sets 9-3503X9

20200902_195934.jpg
 
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