63 409 overheating & other issues

[427John]

Yeah, I'm confused by the "springy" lifters too. I have never seen anything like it. It was only on 3 or 4 of them. Last night when I did the settings they were not springy. Maybe the rods were bent a little and pushing against the slots in the heads and not centering in the rocker?? I did notice a couple are tweaked and I will be replacing them.

The carb and all the casting numbers I've checked match the 340HP, so I don't understand why I would have solid lifters. Not really knowing the history on this motor, anything is possible. If I somehow had a set of 16 bad hydraulic lifters, would they be expected to function exactly like solids? It seems like a stretch to me.

The lifters click away as regular as a clock now, they aren't even trying to take up the slack.

I did try 12 on the intake and that dropped my compression down to 145 so I went for 18. I didn't mess around with the exhaust, it might not hurt to drop it down a little. Since I have to replace my valve cover gaskets, I think I will get my hands on a dial indicator and see what the lift is. That would at least tell me if the cam is a stock lift or not.

I do intend to go ahead with a rebuild on the other block I have this winter. I'm going to keep my eyes out for a set of the 11:1 heads. Anyone know of any for sale?

Thanks again for all your help...

There may even be a possibility of some one installing a solid cam with a set of hydraulic lifters it wouldn't be the first time.It wouldn't even be a problem unless they adjusted the valves like it was a hydraulic cam,if that were the case it would explain a lot of what your seeing.If you get a dial indicator do some checks at the top of the pushrod with the rocker removed,this will give you lobe lift not valve lift but you will be able to see any lash removal ramps indicating a solid lifter cam.

 

[409newby]

A friend in High School bought a 57 Corvette it never seemed to run right an older friend of his came over to see if he could help, turned out it had 1 solid lifter in a hydraulic lifter engine he just replaced the one lifter and all was well.

 

[427John]

The difference is the ports and valves are larger.This will require an intake dedicated to large port heads.By the time you find a set of the 690 heads which in core form are going for about 750-1,000 each then pay for the necessary valves,guides,springs and such as well as the machine shop labor,you'd be better off with aftermarket stuff.Put a modern forged piston and aftermarket rods in it,a modern cam,and stay away from the factory 881 intake.You'll have a sweet running,long lasting engine that'd totally embarress anything that came out in 63,Z-11 not included.

Don would a set of clean bare virgin 690 cores with 1 cracked rocker stud boss for $1200 be a decent price?

 

[Phil Reed]

My name isn't Don, but I would think so.

 

[Don Jacks]

Yes I believe it would,John.,

 

[427John]

Thanks guys.