Dropped my '56 off at Cnut's today

[hutchenc]

I think GM makes a set like this for LS motors Rocky. See here: http://www.jegs.com/p/Chevrolet-Perf...30561/10002/-1

[NickP]

I honestly can't tell how much space I need...I'm thinking it's close to a half inch (vertically) which I can get by moving to a short valve covers. I'm not real thrilled about the idea of modifying the motor mounts at this point vs. changing valve covers. Just gotta find a set that fits.

Well, the alteration is simple and far less expensive than new covers but regardless, keep us posted - good stuff. How's the balancer clearance now?

[hutchenc]

I think I have a solid 1" clearance to the R&P. If I knew how to weld I might attempt the modification, but I don't

[chevynut]

Hi Chad, just got back from the mountains chasing wapiti.

If your balancer is 6 3/4" and we planned for an 8" balancer, that's a 5/8" difference in radius. Add our roughly 5/16" designed balancer to rack clearance and you're at 15/16". If you're higher than that, something is still wrong.

You say you have 4 degrees now...is that counting the 1.5 degrees for the frame? Or is the engine now 5.5 degrees relative to the frame?

If you want to bring the car down here I'll modify the mounts for you to drop the engine down or forward some, if that helps. I still don't understand why with so many SBC applications nobody's had this issue...maybe they cut the firewall out or fixed it some other way. Is it just the tall covers? Maybe other guys use short ones.

What would have helped prevent this? Should we put the SBC engines a little further forward? Looking for some feedback since we have a couple projects coming up with SBCs, and I don't want any of these issues.

[hutchenc]

Hey Laz...the angle is 4 degrees relative to the ground, not the frame. Frame is still at around a 1.5 degree slope going forward, so the motor, relative to the frame is now at 5.5 degrees (which is where it should be I think).

Let me re-measure the distance between the R&P and the balance...it's close to an inch, but I only eyeballed it so I could be wrong. I'll measure it.

As far as the clearance...I think it's the covers. The tall ones are just too tall with the motor up a bit higher than it was before. It was tight before, especially to the battery box (in fact it was so close to the battery box that I couldn't run a breather on the rear of the cover on the passenger side).

Let me pick up a set of short covers and report back. If it fits (and I think it will), I'm not gonna worry about it.

[55 Rescue Dog]

Don't forget to leave some room for engine movement too, especially with the power that engine looks to put out. I think the driver side it the one that will want to raise though.

[hutchenc]

So I measured the interference point from the rear of the passenger side head to the firewall using a standard credit card (which is 3 3/8" long). Looks like I have 3 inches of clearance so a standard short SBC valve cover will work fine, but the taller ones that are over 3 inches tall, just no way. Anything over 3" is gonna hit the firewall on the passenger side. I think I could maybe squeak a 3" tall valve cover under there...barely. Driver's side is not an issue as long as the motor is at the right angle, which it was not at first.

I also measured the highest point that my rockers' poly locks get to from the valve cover rail...it's right at 2 1/8 inches so a stock cover at about 2 1/2 inches should work just fine. This is on a set of big AFR heads...I don't think this would be the same on a set of stock SBC heads...nor would the interference with the firewall. The AFR heads have .750 deck...I think that's at least 1/4" more than a standard SBC head. Point is, they're taller than stock heads so all of this will vary by application. I should also mention that I'm running a Dart SHP block, not a stock SBC block...I think the dimensions are the same, but I could be wrong.

I ordered a set of die cast Billet Specialties short covers that are supposed to be 2 1/2 to 2 5/8" tall.

I also measured the clearance between the damper and the rack...it's just under 1" so it's spot on at the 15/16" that Lazlo said it should be at.

Lazlo...I'm not gonna worry about the height of the motor and I don't think you should either, but you might warn any of your future SBC customers that a tall valve cover might present some issues unless you lower the motor a solid 5/8". At that point, the oil pan (well, mine does anyhow, but it's also not stock, it's a custom Milodon pan) gets pretty close to the cross-member though so I'm not sure that's a great option. No worries here though...the tall ones I have will go on my '72 Camaro

I'll post pictures when I get the new covers on.

BTW...I spent my evening watching the Texas vs. ND game, suck it Domers!!!

[NickP]

I also measured the highest point that my rockers' poly locks get to from the valve cover rail...it's right at 2 1/8 inches so a stock cover at about 2 1/2 inches should work just fine.

During normal operation, do the rockers exceed this 2-1/8" during their motion?

[chevynut]

During normal operation, do the rockers exceed this 2-1/8" during their motion?

My observation is that the rockers never come anywhere near as high at the polylocks. In fact, I don't know why they don't make the polylocks fit completely inside the rockers so you can use a socket on them and so they don't protrude above the top of the rocker. Something like this made to match the rockers would be nice so they're not so damn tall. The locking stud can be a lot shorter than it is, and it usually sits way down in the nut anyhow:

[hutchenc]

Yeah Lazlo is right...the tip of the rockers never gets close to being as high as the poly lock. I guess Comp makes some shorter ones, but I don't think I need to worry about it. I *think* part of the reason they're so tall is so one can use a stud girdle on the rockers, but you'd think that it would only be an option.

I had 1.6:1 rockers on my old 383 with short covers and they fit just fine, so I'm not worried.