Can J heads bee used with a roller cam?

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Dmopower

Dmopower

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Can anyone tell me if SBM 915 J heads can be used with a Hyd roller cam? What if anything needs done to make this work? Is there an issue with the push rod hole?

Thanks.
 
You’ll need to clearance the pushrod hole. The shorter pushrod has a more severe angle. A die grinder and bit for the iron is needed.

The valve spring needed may take some work for use. The inner spring may interfere with the valve seal and the springs installed height can be an issue.

Comp Cams (and other places) sell valve seat cutters that narrow the seal area for different seals and lower the step as well as make the seat bigger which normally is tan issue with an OEM head because MoPar uses wide springs.
 
Cam manufacturer should be able to match some beehive springs with the proper pressures. They would provide plenty of rocker-to-spring/retainer clearance even if you have to with slightly bigger diameter springs.
 
Any head work done so far? Factory valves or .100 longer 11/32 stem chevy valves? Number of valve grooves if factory? Exhaust rotators? I've seen several stock trucks with J heads and rotators before...
 
Well of course they can. You can set them up for an .850 lift solid roller if that's what you want. The key is "set them up correctly".
 
Locomotion said:
Cam manufacturer should be able to match some beehive springs with the proper pressures. They would provide plenty of rocker-to-spring/retainer clearance even if you have to with slightly bigger diameter springs.
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I love the beehive springs. The solve a lot of problems with clearances
and I use them everywhere = if I can find the right spring pressure for the application.
The hold up their pressure very well over time.
 
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Garrett Ellison said:
Any head work done so far? Factory valves or .100 longer 11/32 stem chevy valves? Number of valve grooves if factory? Exhaust rotators? I've seen several stock trucks with J heads and rotators before...
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I picked up a set of J heads. I'm going from 1.88 to 2.02 They have good thick wall 3/8" bronze guides and polished chambers. I'm having hardened seats installed, Vinton seals. I'm using Hughes stainless 2.02 and 1.6 valves. Std length. Both single groove locks. I wanted to be sure there was no issue with the pushrod that can't be addressed before having the seats installed. They are cleaned and checked for cracks and all is good.
 
That’s very good! I don’t know what your installed height is going to come in at (probably between 1.65 to 1.75) but you’ll have plenty of options for springs and retainers. What cam and rockers do you intend on running?
 
Garrett Ellison said:
That’s very good! I don’t know what your installed height is going to come in at (probably between 1.65 to 1.75) but you’ll have plenty of options for springs and retainers. What cam and rockers do you intend on running?
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Im running the little 222 226 @.050 roller and the springs they recommend and I have Comp cams Pro magnum roller rocker arms. Its a 3.79" 6.125" street engine. 383" But I'm planning on putting a NOS kit on it.
 
You will have to grind the push rod holes in the head towards the valve cover rail at the top and towards the cylinder at the bottom. You will want to make the holes into pill shapes at each end top and bottom so that by the time you're done you essentially have an hourglass shape push rod hole.
 
MOPAROFFICIAL said:
You will have to grind the push rod holes in the head towards the valve cover rail at the top and towards the cylinder at the bottom. You will want to make the holes into pill shapes at each end top and bottom so that by the time you're done you essentially have an hourglass shape push rod hole.
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Can this area be machined, and a bronze sleeve put in? I read something about that. Also Are there any pics out there of the work someone has done to accomplish this feat. Pics are great. Thank you.
 
You could but it will not be required in that modification.
Usually, the bushing is put into pushrod holes
mainly on the later engines for when the intake
is ported larger as i recall.
 
Absolutely, any LA head has things that make it not a “throw them on and you’re done” but sure. Like stated above. You need to fit a spring that is correct for the cam. In a pretty narrow envelope. Certain characteristics of the LA make it, not hard, but you need to pay attention. My real question is why roller? If you already have it, ok, but I’m running solid flat tappet at E/T levels I should have a bar. Now there is performance to be had, but are you chasing every last HP? I would be more worried about the roller lifter (aftermarket?)dumping oil pressure.
 
In reality, for me I’m forced into the same “small envelope” but the upper end. I’m limited in gross valve lift, but if I can snap the valve open to a useable lift quicker…….bob’s your uncle! Roller is on my list.
 
Roller is the bees knees for throttle response.

Atm I would rather have a roller in the .550 gross lift... than a solid .
If you want little bit of extra ... go solid roller.
 
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