5.9 Magnum Street Build - with dyno numbers

[mgoblue9798]

I put a pair of Indy LAX heads on my 360 back in 2012. They of course are (were, since I believe they are no longer available) Magnum type heads with provision for rocker arm shafts like a pre-Magnum small block. I put them on as delivered except for port matching. With less than 100 miles on them, the #7 intake valve stuck open. I drove it the five miles to home. Popped the driver's side valve cover and the problem was obvious.

View attachment 1716483012

The #7 intake valve looked like this:

View attachment 1716483013

Fortunately, I had factory replacement cast pistons that were .090 below deck at TDC. Also, the cam was a mild Mopar Performance grind with .450/.455 lift. Once the valve bent, it cleared the piston - without even leaving a mark on it. The valve seat in the head was undamaged. Bought one new intake valve from Indy, the machine shop opened the guide a tad, and put it back together. I don't think I even had to replace the pushrod, but it's been a while, so maybe I'm just not remembering.

That was before I ever heard of FABO. If I had been able to read this post back then, I probably would have gone ahead and installed bronze wall liners, but I did not. Anyway, it's been fine for more than a dozen years now.

Thanks for sharing this. It is the first I have read about the Indy RHS heads having guide issues. Guess it is time to get bronze guides installed in the set I am using on a new build.

 

[TT5.9mag]

Well, got my heads fixed. Ended up getting some valves from Pro Stock in the size the shop requested.

I had other valves starting to fail other than the one that actually got stuck like Ram mentioned.

If you have the older EQ heads, I would run bronze guides!

The culprit is pictured below.

View attachment 1716526496

Man that took a while. I’m glad you’re getting back together. When is dyno day?

 

[DMC_78]

Man that took a while. I’m glad you’re getting back together. When is dyno day?

Likely be another few months. I need to order a few more parts and button things up again.

I can’t wait, hearing the engine on the dyno is addictive.