Valve cover, spring retainer clearance?

Discussion of the 331-354-392 HEMIs.

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NE57
Posts: 192
Joined: Fri Mar 27, 2009 12:54 pm

Valve cover, spring retainer clearance?

Post by NE57 »

I was doing a mock up and discovered that the stock steel valve covers interfere with the spring retainers. Now that my attention is drawn to it, I can see the outside edge of the retainers overhang the cover rail by about half: that is the retainer goes about halfway over the rail surface, more so on the intake side than the exhaust side. Looks like simply 'taller' covers won't do the trick, they need to be 'wider'. I bought these heads finished, they are what they are. I'll guess the springs are larger diameter than stock and maybe the valve stems are longer. The valve heads are certainly quite large.
I was planning on getting some aluminum covers anyway at some point. So my question is.... is there more clearance built into all aluminum covers generally or must I look for some specific make/model? And/or is there enough material to grind out some clearance? Its not ALOT of interference...I can snap the covers over the valves but needed to pry them off again.

Thanks
dan miller
Posts: 86
Joined: Wed Dec 27, 2006 5:05 am

Re: Valve cover, spring retainer clearance?

Post by dan miller »

This a common issue, and there are (at least) two ways to resolve it. Most cast valve covers can be ground for clearance - Hot Heads cast valve covers require about a half hour of fitting/grinding when using large valve springs and long valves. Valve cover spacers can also be utilized with the stock valve covers (my favorite, but problematic, as they have a tendency to leak), but they're expensive and require special spark plug tubes

Another thing to keep an eye on is intake rocker arm to spark plug tube interference. I made a tool, and we smack a dent in the tube for clearance. We also notch the tube flange at the 12 o'clock position for orientation.

Danny
NE57
Posts: 192
Joined: Fri Mar 27, 2009 12:54 pm

Re: Valve cover, spring retainer clearance?

Post by NE57 »

Thanks Danny.
NE57
Posts: 192
Joined: Fri Mar 27, 2009 12:54 pm

Re: Valve cover, spring retainer clearance?

Post by NE57 »

Problem solved. I got a pair of PAW finned covers and they have room to spare. And damn they look good!
But they are big, so big I hope I don't have a fitment problem with the fenderwells. Well, that's what torches and hammers are for, right?

When I get the chance I'll post a side by side comparison pic.
NE57
Posts: 192
Joined: Fri Mar 27, 2009 12:54 pm

Re: Valve cover, spring retainer clearance?

Post by NE57 »

Ok here's the pics, mainly for any other newbs who might run into the same situation, you hemi greybeards already know this I'm sure. You can see how the retainers left light scratches in the steel cover, the PAWs don't interfere at all. You can also see how the overall sizes compare, wider, taller.
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392heminut
Posts: 488
Joined: Sat Nov 30, 2002 2:16 pm

Re: Valve cover, spring retainer clearance?

Post by 392heminut »

BIG difference in height! Do the PAW covers use stock spark plug tubes or 426 tubes?
Owner of the Poor Man's Hemi Cuda
NE57
Posts: 192
Joined: Fri Mar 27, 2009 12:54 pm

Re: Valve cover, spring retainer clearance?

Post by NE57 »

PAW sells tubes that fit these covers. I don't know if other tubes might fit. I'll measure them and post. Yeah height has me a little concerned because if they're taller they're also wider once installed in a really confined engine bay. Plus, IF I do fab a crossram the height may have an impact on fitting a plenum and maybe runner angles, dunno till I try. Oh yeah, and there might be master cylinder issues beyond what I've read about so far., Glad I decided on hydraulic lifters. We'll see what we see.
NE57
Posts: 192
Joined: Fri Mar 27, 2009 12:54 pm

Re: Valve cover, spring retainer clearance?

Post by NE57 »

Here's the tubes , side by side. You can see the stock tube has a flare and the PAW has a stepped end.
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392heminut
Posts: 488
Joined: Sat Nov 30, 2002 2:16 pm

Re: Valve cover, spring retainer clearance?

Post by 392heminut »

Not sure if it's the same length, but the PAW tube looks like the 426 hemi tubes.
Owner of the Poor Man's Hemi Cuda
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