Cylinder head center bolt access tricks wanted

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Duane

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i am sure some of the members here with racing cylinder heads with large diameter valve springs have run into this problem. How do you tighten or loosen the center head bolt that is in between the two exhaust valve springs. I have always had to remove one spring with the engine still on the motor to get a socket on that bolt or in my case the stud nut.
Does anyone have a trick or special tool they can share with me to get at that bolt without having to remove a valve spring?

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12 point nuts helps but there are times when you have to pull,the springs with the heads on. SBC's have the same issues.
 
Smaller diameter head bolts normally do the trick. At work, we modify our tools to suite the job sometimes and grinding down a sockets diameter is one of them.

Perhaps! A 3/8th drive socket is slimmer than a 1/2? Also different manufacturers have different diameter sizes. Perhaps another brand socket?

Good luck. I KNOW this is a pain.
 
Might be costly, I've never checked into it, but female hex head fastners would solve that problem.
 
crackedback said:
3/8 drive helps a bit.
Click to expand...
3/8" drive , deepwell socket , turned down. Worked on my sbc, and my alum. head 440/505. Gotta be a way! I even remember prying the springs over a hair to spread them. They usually will move some in the heads spring cups.
 
famous bob said:
3/8" drive , deepwell socket , turned down. Worked on my sbc, and my alum. head 440/505. Gotta be a way! I even remember prying the springs over a hair to spread them. They usually will move some in the heads spring cups.
Click to expand...

I've got a Snap On 3/8 drive deep socket I use if needed ...and/or using ARP head bolts...
 
RustyRatRod said:
Might be costly, I've never checked into it, but female hex head fastners would solve that problem.
Click to expand...
Like Allen bolts or socket head cap screws? I'm sure they are made in the correct grade, sizes & lengths. You'd have to piece together what you need. Here is a metric set made by ARP for a VW 1.8 L engine.
arp-204-3902_w.jpg
 
Lots of current engines use head bolts w/an Allen or Triple-square head on them, unfortunately they are all metric, and most are much longer than older apps. The ones
above would be triple-squares which require like bits, and excellent quality ones at that. Hyundai/Kia and others are using the same, and they are all TTY fasteners.
Go to McMaster-Carr and look up reduced head fasteners, they are made for these very situations.....................................

Someone else already mentioned ARP, those are reduced hex-headed......
 
Never heard “Triple Square” before. We just call them “Star Key.”
 
Killer6 said:
Lots of current engines use head bolts w/an Allen or Triple-square head on them, unfortunately they are all metric, and most are much longer than older apps. The ones
above would be triple-squares which require like bits, and excellent quality ones at that. Hyundai/Kia and others are using the same, and they are all TTY fasteners.
Go to McMaster-Carr and look up reduced head fasteners, they are made for these very situations.....................................

Someone else already mentioned ARP, those are reduced hex-headed......
Click to expand...

Toyota has used them for years. I always just use a 10mm allen tool, because it fits perfectly. No reason you cannot piece together the same style bolts for the heads on a Chrysler.....it may not be very cost effective, but it surely would eliminate a frustrating problem.
 
Right, most foreign OHC heads have used 'em because clearance is at a premium, as long as You've got quality bits You're good to go.
BTW, You only need 2 fasteners at the position between exh. valves. Even tho' I'm sure the ARP bolts are a reduced head, You probably gotta buy the set(not a bad idea),
but here anyway,......and get some grade 8 washers to go with them................
McMaster-Carr
 
Killer6 said:
Right, most foreign OHC heads have used 'em because clearance is at a premium, as long as You've got quality bits You're good to go.
BTW, You only need 2 fasteners at the position between exh. valves. Even tho' I'm sure the ARP bolts are a reduced head, You probably gotta buy the set(not a bad idea),
but here anyway,......and get some grade 8 washers to go with them................
McMaster-Carr
Click to expand...
ARP only makes sets of socket head capscrew-style head bolts for a few engines. Nothing for Mopars.
 
Won't a 12 point male head work? "as in" aircraft style bolts?

12pt-bolt__82047.1485549347.420.340.jpg
 
Removing one of the surrounding springs will usually give you plenty of room. Or grind down a cheap 3/8 drive deep socket, as said.
 
mopowers said:
Removing one of the surrounding springs will usually give you plenty of room. Or grind down a cheap 3/8 drive deep socket, as said.
Click to expand...
Yes trying to figure away around having to remove a spring. Especially these very stiff racing springs.
 
Killer6 said:
Right, most foreign OHC heads have used 'em because clearance is at a premium, as long as You've got quality bits You're good to go.
BTW, You only need 2 fasteners at the position between exh. valves. Even tho' I'm sure the ARP bolts are a reduced head, You probably gotta buy the set(not a bad idea),
but here anyway,......and get some grade 8 washers to go with them................
McMaster-Carr
Click to expand...

Those look good. Then there's these too! I just plugged in 1/2 20......I think that's it. My ols *** caint remember. lol They have all sizes though.

McMaster-Carr
 
Usually a 12 point socket is thinner, fits in more places...
I have turned down sockets in the lathe a few times for getting in somewhere.
Suprising how soft they are.
 
69_340_GTS said:
ARP only makes sets of socket head capscrew-style head bolts for a few engines. Nothing for Mopars.
Click to expand...
The ARP bolt kits I've installed had an undersize head, like 5/8 instead of the std. 3/4 for the thread size of the fastener.
 
The same craftsman 3/4 socket works on my stuff, but I stay with around 1.437 OD spring diameters, still have to shove it by them.
 
ARP's catalog for 5-packs shows the reduced head size for 1/2" bolts at 9/16"......................................
 
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