Valve Guide Clearance Question 5.9 cams
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Amateur
Joined: Sep 2023
Posts: 28
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From: Northern Virginia, USA
Valve Guide Clearance Question 5.9 cams
I was asking the wrong question in a previous post about different tolerances/clearances, so to put it plainly, what is the OE clearance from the valve spring retainer and the guide/seal to allow valve lift? And how does an aftermarket (hughes 1278) spring retainer make a difference in that number, if at all? I've seen dimensions that show the depth on the aftermarket retainer being shallower than that of others (8mm vs 11mm), so would that allow for more lift in theory?
I've seen claims that OE springs bind @.520 and will have retainer/guide contact at roughly .525". The hughes 1110p's will bind up @ .600", but I do not know if that retainer clearance remains unchanged or not. Not looking forward to removing heads if I don't have to, if so I'll probably compromise with the comp 20-745-9 instead of the 20-746-9 since it has 0.025" less lift
After all, just need it to smoke the tires and pull a 3/4 ton army trailer, while sounding good at the same time.
If this helps, here are the specs of the cam I'm getting:
.317"/.317" lobe & w/ factory 1.6 rockers .506"/.506" gross lift
Duration @.5" = 216int, 224 exh
114LSA because it's a daily
I've seen claims that OE springs bind @.520 and will have retainer/guide contact at roughly .525". The hughes 1110p's will bind up @ .600", but I do not know if that retainer clearance remains unchanged or not. Not looking forward to removing heads if I don't have to, if so I'll probably compromise with the comp 20-745-9 instead of the 20-746-9 since it has 0.025" less lift
After all, just need it to smoke the tires and pull a 3/4 ton army trailer, while sounding good at the same time.If this helps, here are the specs of the cam I'm getting:
.317"/.317" lobe & w/ factory 1.6 rockers .506"/.506" gross lift
Duration @.5" = 216int, 224 exh
114LSA because it's a daily
Administrator
Joined: Apr 2010
Posts: 87,453
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From: Clayton MI
3mm is about 0.12 inches. That's a lot when it comes to valve clearance. Stock heads are limited to .480 lift. That is likely retainer/guide contact. Never a good scene. Don't know if you will have to machine down the guides for that cam....... I would have a chat with the manufacturer, see what they say.
Also, keep in mind, you are going to NEED a tune, for that cam to run worth beans in your truck. The computer is forgiving, but, it ain't THAT forgiving.
Also, keep in mind, you are going to NEED a tune, for that cam to run worth beans in your truck. The computer is forgiving, but, it ain't THAT forgiving.
Thread Starter
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Amateur
Joined: Sep 2023
Posts: 28
Likes: 2
From: Northern Virginia, USA
Thanks for the feedback. I've been in contact with a guy who tunes mopars in my area, EFI Customs is their name 
I met another guy who cammed his otherwise stock 5.9 durango with a custom grind that gave him .513 lift, no head/valve work just cam and springs and says he has about .040" clearance with the retainers and guides. I'll verify measurements when I get everything on to be on the safe side, and contact Comp Cams see what they have to say
I met another guy who cammed his otherwise stock 5.9 durango with a custom grind that gave him .513 lift, no head/valve work just cam and springs and says he has about .040" clearance with the retainers and guides. I'll verify measurements when I get everything on to be on the safe side, and contact Comp Cams see what they have to say
