Bonehead is back to work

It is running, but not the way I want it to. We are changing a few things to get it to idle, then I can get it to run. Too much air in the intake, and not enough gas. So I am necking down the runners, and switching to bigger carbs.

Looking good, nice to hear it running. Is it possible to reduce the size of the plenum? That may help, though larger carbs may not necessarily help getting it to idle right - they may just leak to much air to start with. On my 472 with my homemade intake, I used Holley 600 vacuum secondary factory rebuilt carbs (cheapest!), right out of the box, no jetting changes and it would idle right down to 750 rpm - Crane 500 lift, 300 degree advertised duration cam, so it had a real lumpy idle. Otherwise the engine was stock, ran the carbs straight up, no progressive linkage.

How big in diameter are the runners BH?

2-1/4 but I am reducing them down to 1-3/8ths. ZZ, I can reduce the plenum size if I have too. I am pretty close, just need to dial in. We put the larger carbs on, and it seemed to help.

sounds like air speed in the runner is a big issue with that big of a runner yes?

I have a couple of experts working with me on this. A long time drag racer engine builder, says it is a great set up for a drag car, because you could dump all the fuel you wanted into it. But to idle, it is too much. We are knocking around some new ideas, but probably necking down the runners will work best.

Bonehead said:

I have a couple of experts working with me on this. A long time drag racer engine builder, says it is a great set up for a drag car, because you could dump all the fuel you wanted into it. But to idle, it is too much. We are knocking around some new ideas, but probably necking down the runners will work best.

Click to expand...

can you just sneak a reduced pipe inside the runners? that way you don't have to rebuild the entire manifold.

That is the plan, and thee reducers are built. I am also getting the intake machined, to get it to seal a little better.

Great truck!

Bonehead said:

It is running, but not the way I want it to. We are changing a few things to get it to idle, then I can get it to run. Too much air in the intake, and not enough gas. So I am necking down the runners, and switching to bigger carbs.

Click to expand...

Not to change the subject,but was wondering do you mount the cab directly to the frame or did you use some type of rubber mount?

The cab on this one is welded right into the frame. With the cab being so cut up, the best thing for this one, was to mold the cab right into the roll bar.

How rough on the butt and back does that feel without any dampeners between the cab and frame? I've always wondered how that would affect ride.

The suspension takes all the bumps, but you do get the vibration. It is a real seat of the pants kind of ride.

This is really a process, not for the faint of heart. So here is what has gone down. We fired off the truck, and it was rough. I have dealt with two outside people on this build, the machinist, and the engine builder, (oh and the upholster). At any rate the engine builder told me it has to be the intake. We talked about it for a while, and I agreed to re build the intake. After I got the intake re-built, the engine builder finds out part of the problem was a stuck valve. He pulled the heads and found the rockers were crap.
Even though they were new, they had a lot of side to side slack. The valves were shot, after the car ran for 20 minutes. Not only that, further inspection found debris, had gotten into the main bearings, and everything else in the engine. There was also some surface rust inside the engine, that is a mystery. I just got the truck back from the engine shop, and the machine shop after almost 3 months. The engine was totally rebuilt, and re-machined, and my checking account got cleaned as well. Now the engine starts and runs every time, and sounds great. Now that I have it back, I am working on it every night. The punch list is getting smaller. But while I didn't have the truck, I was thinking about the truck, so now I have a few more things to add to the build. More on that later. The following pictures are the reducers for the intake, the intake, and the seats. Also a new and larger wire for the starter has been added, which will be inside copper tube tomorrow. The really cool badge radiator cap leaked, and had to be replaced. So I have a new one to build.

Glad to hear the engine woes have been solved, the re-worked intake looks great. I had the same trouble with the stock Caddy rockers when going with a 500 lift cam, chewed them up and beat up the valve stems, solved it with a set of adapted SB Chev roller rockers and new valves.
So many kool details on this build, I could spend hours looking at it and still miss things. [cl[cl[cl

That really is a bummer on the engine issues... Did they not inspect the bore size for the lifters or what was the end issue that caused the size issue?

Thanks ZZ. DR, the problem are these rockers shown on the upper right. They are junk.

The other sets look much more robust =)

Bonehead, enjoyed following this build lot's of imagination
glad you got the engine woo's worked out.

I hate having problems with engine builders! Had several issues with my nailhead that ran me up the wall & preformed a walletectomy on me as well! Always good to get that straightened out but frustrating because it shouldn't have ever happened in the 1st place! I hate paying for the same work twice!

BoB

Did the guy who did the first rebuild do the second rebuild? Debris and rust left in the engine sounds like it never got cleaned after machining. Very disturbing.