Well, I have had the jones for better mileage, cooler running and of course, more power now since I bought my Barth.

I always thought I had 'adequate' power until last years trip through the mountains of PA gave me the dreaded position of "RV lumbering up hills, holding everyone else up behind him".

Hate that.

Well, on our last voyage, I blew the seal between the drivers side exhaust manifold and the exhaust pipe.

Tried to tighten it on the road *just to reduce the noise* and managed to break one of the studs.

Drove home sounding like a ghetto cruiser.

Yesterday began the project in earnest.

Managed to round off not one, two but three exhaust manifold bolts. I guess them not being touched since it was built in '87 was not a good thing.

Thank God I had previously purchased an extractor set from Craftsman, and it made short work of them all.

The manifold fell free and a couple bolts pulled the obnoxious AIR injector off.

Found out there are TWO A.I.R. pumps not one, and wondered how much HP they suck off the crank.

They have a short life expectancy once I get the headers installed. I'll keep everything in a box in case it goes someday to a buyer who needs it, but in my state big trucks are emissions exempt.

It took me about 15 minutes to figure out the dipstick was a very tight press fit, lol.

The exhaust piping goes from a reasonable 2.5 inches dual exhaust to a bewildering 2 inches after the muffler.

Whose bright idea was that?

The mufflers themselves are HUGE, must weigh 30 pounds apiece. I plan on replacing them with Flowmasters as soon as I can measure the offsets of the pipe.

Can't do much about the tail pipes, figured they would be $$ to have redone in a bigger diameter..dang it all.

Hope the headers and lower restriction mufflers do something positive, plan on fabricating a second cold air intake for the air filter too.

Wish me luck!

quote:

Originally posted by Windsor Dalrymple:
Managed to round off not one, two but three exhaust manifold bolts. I guess them not being touched since it was built in '87 was not a good thing.

Thank God I had previously purchased an extractor set from Craftsman, and it made short work of them all.

What extractors were they, exactly?

quote:

They have a short life expectancy once I get the headers installed. I'll keep everything in a box in case it goes someday to a buyer who needs it, but in my state big trucks are emissions exempt.

Rules change and smog law areas get expanded. Those pumps like to freeze up sitting. The vanes get stuck. I would spray some sort of moly oil in the intake while rotating the shaft to try to avoid the freezing.

quote:

The exhaust piping goes from a reasonable 2.5 inches dual exhaust to a bewildering 2 inches after the muffler.

Whose bright idea was that? Can't do much about the tail pipes, figured they would be $$ to have redone in a bigger diameter..dang it all.

I use a 90 degree 2 1/2 turnout at the back of each muffler? You could do it yourself. The exit is ahead of the drive axle.

quote:

I plan on replacing them with Flowmasters as soon as I can measure the offsets of the pipe.

I know a guy who had trouble with Flowmasters on his MH. I always listen to what he says. The little ones were loud and the big ones hurt power. He went to Dynomax and is happy.

Now would be a good time to consider an H or X pipe. For torque and quietness.

quote:

Hope the headers and lower restriction mufflers do something positive, plan on fabricating a second cold air intake for the air filter too.

Are you sure you need a second air intake on the filter? I would suggest making a manometer and checking. Or buy a Filter Minder. You need one anyway. Everybody needs one. It will pay for itself in the money you will save by replacing the filter only when it is necessary.

Just figured out that the second filter is probably a spark arrestor for backfire protection, so it can stay.

The extractor set is a Craftsman piece, and I further purchased a stud extractor by Lisle.

I am definitely building an H pipe.

Probably going to go with either dynomax or magnaflow.

I am going to evaluate the stock exhaust, but if it does not please me, I will go the turnout path.

Before I found my Barth (1993 32' Regency 300hp Cat) I dealt with your P-30 problem with a 454 Chevy Truck engine powered SOB. I installed headers and large mufflers because I wanted quiet rather than Flowmaster sound. After completing the plumbing I dyno'ed the beast and found little improvement in torque or hp. I then replaced the HEI ignition with MSD High Power transistor ignition module/coil and 8mm wires. These are available just about anywhere. I saw an increase of 30% in torque (hill climbing) and about 3-4 mpg in economy. The reduction in back pressure made possible by the headers tends to scavenge the cylinders causing a lean condition that changes the optimum firing point of the plugs. You might talk with a race shop about this, but my SOB greatly improved after this change. The MSD change cost me just about $300.
Good luck
Tom

My cardiologist has forbidden mileage checking, but I am very happy with my MSD 6A. I also use their adjustable timing add on for the 6A, allowing me to adjust my ignition advance according to temp, grade, load and fuel quality.

I have used the MSD on a number of vehicles, and it has improved every one. The full roller rump-rump 502 in my boat will not run for very long between 2000-3000 RPM without it, due to fuel puddling issues and cam overlap.

Thanks for the advice.

I put in a Moroso HEI cap and large cap wires made especially for RV's. They are made of high temp silicone and I used Bosch Platinum plugs.

Hopefully, this will head that issue off at the pass.