Have some family matters to attend to so have not even been in 71 for a week. Hope to get back to work soon.

Well ole 71 has been sitting for over for 2 weeks, went out fired it up and stepped on the brakes, pedal went to the floor! Filled the master cylinder and bled it, the pedal returned. So got a leak somewhere, looked under 71 and no drip spots, but the frame is wet near where the new remote power brake modules were installed, gonna have to jack it up and find out what's going on, funny hard pedal does not seem to give way under pressure but 2 weeks of just sitting the rear master cylinder fluid reservoir was completely drained.

Love this coach!!!

I have faith that you will get this coach back to camping

Thanks for the faith!! H,C,& S!!!!

Went out today fired up ole 71 to put it up on the wood ramps to look for brake line leaks and another push rod had popped off the rocker arm, looks like more rocker arm studs are coming out of the heads, push rods are straight and the top of the studs are higher than the others. Must happen on start up when it is shut off it seems fine.

Off to the hot rod shop Monday to get more threaded studs, guess I will just get the complete set, seems this is going to continue to be a pain in the behind. Wonder why GM just pressed the studs in the head with no locking device, accountants do anything to save a buck!

Like old Tom McCahill said when they asked him long ago, "Why do the auto companies sell you a car for $5,000 and give you a two dollar jack?"

Answer: they ran out of one dollar jacks....

the engineering dept reports to the accounting VP. always have.

Went over to the hot rod shop, they had cracked open a set of treaded rocker studs and so far, sold me three. Bought the whole set of 16! May not use them all, but one day maybe do the both heads and avoid future problems. A smart guy would do that for sure!!

For now believe will only fix the two that have come loose. Probably not today, super hot out!!!

Added:
Well it is hot but went out and got started on the stud replacement, got the loose ones out and threaded one about half way, heat got to me and went back in the house, love A/C!!!

Replaced the valve studs, and did an initial engine turn over, broke a push rod!! Yes; one of the valves was stuck in the open position. Tried to free it up with a tappy-tap hammer, no luck, now the spring is completely depressed and even with that spring load it does not return the valve to closed position. now I am afraid to turn the engine over for fear of piston and valve interference. gotta try to get that valve back up,,,tomorrows job!!!

Looks like a big job, remove and replace the heads. Not a good day for ole 71!!!

Not a fun job , but I bet replacing the heads will stop a lot of your headaches

Soon you'll be

Pull em off, get the valves ground, guides checked, exhaust manifold bolts replaced if they break. Put in the rest of those threaded bolts and you'll never have to work on them again.

quote:

remove and replace the heads. Not a good day for ole 71

Duane!

It might be a great day!

A few thoughts... Next time you look at the cylinder head, get the casting number. That is an identifier to the mold that Chevrolet used. "Engine guys" use that number to assess the power and torque potential of the casting. Factors about that include the valve size, the combustion chamber volume, intake runner volume. I recall that the "041" head on the 350 used in the 1970 El Camino, with the 64cc combustion chamber, gave a 10.25:1 compression ratio, with flat top pistons. Your engine probably has dished pistons. So, my idea is you want to assess what you have before you go for the rebuild. If you have something that gives a low compression ratio, you might want to "up it" a little bit by changing to a different casting number, and having those built. Intake valves range in size from 1.72" to 1.94" to 2.02" diameter. Generally larger is better for air flow, but you don't need the 2.02 and might not want them either. They are considered a high HP feature and you want torque. If you have 1.72" you might want 1.94". Cylinder head castings from the 1950s to 1987 will work.

You will also want to be sure the rebuilder uses hardened valve seats for the modern unleaded fuels.

If you yank the heads, you might want to consider having the exhaust manifolds checked for planarity, and have them resurfaced if they have warped. Probably while off, you can also have new studs put in the output side, at the flange.

Jegs is offering an "041" head for $265. Summit is offering a new casting with 72cc combustion chamber for $400. These come loaded with valves and springs for both. Free shipping too. You can also find "locals" that do rebuilds and might have a stock of different casting numbers to choose from.

If the heads come off, can we help you pick out a new intake manifold?

Happy Motoring,
Matt

There is a local hot rod shop here, they have several sets of 350 heads, the owner is retiring and wants to sell off as much stuff as he can.

The heads he is really fond of have been rebuilt, with stainless steel valves and new seats. he has other sets that are less expensive, just to confirm, does anyone have experience with stainless steel valves?? Not sure about the year or origin of the heads what should I look for?? He will sell me the set for $350 and will probably toss in an upper engine gasket set??

If a smart guy was doing this he would probably go to headers instead of the manifolds, one is newer than the other has ports for AIR pumps.

It is super hot here, cooler days for the weekend maybe get started pulling the heads then, but next week back to the oven!1

I have no experience with stainless valves, perhaps others can comment.

However, I am a real fan of headers. They will make the engine run smoother and stronger. They are much lighter and easier to install. They really cut down on the heat soak after shutdown. Instead of hundreds of pounds of cast iron to cool down you have thinner steel tubes.

They sound good too.

quote:

Not sure about the year or origin of the heads what should I look for??

the big thing about the heads is the casting number. the picture shows the 041 heads.

there are some index files on the internet about the heads, this is an example. https://outintheshop.com/faq/casting/heads.html

One of the files shows that the 041 heads does not have bolt holes in the ends of the heads, but the set I had did. Make sure the holes you need for mounting the alternator are in place, and the PS pump.

"The main advantage to stainless steel valves is that they can stand the high heat ranges and lack of cushioning that unleaded fuel creates." I read that on the internet, that sounds good. You want to be sure that the valve seats are compatible, I guess, I don't really know. You want to be sure that there were no cracks around the valve seats. A good machinist will be sure of this. Find out what valve springs are in place, you probably don't have to worry about binding with the high lift cams, but ask anyway.

Chevrolet changed intake manifold bolt positions and angles in 1987. If you want to run your stock manifold, that is a concern. If you know that you want to buy an aftermarket manifold, you have choices of both designs.

I think I heard that the castings of more recent decades are thinner walls, trying to reduce weight. Thicker is better for my perspective on the Barth.

One more thing: if you go with the post 1987 heads, you not only need the later model intake manifold, you will also need different valve covers. These are the center bolt for hold downs. You presently have the 4 perimeter style hold downs.

Happy Motoring!
Matt

Well the heat wave has slowed down, still warm but was able to get a bit done on the head job for 71. BTW that stuck valve did return to its seat so the engine can be rotated.

Got the exhaust manifolds loose, they used anti-seize, although they were tight, but broke free with the electric impact. Have not started on the intake yet. Maybe tomorrow. Draining the engine.

Probably not able to lift it or the heads from the doghouse. Grandson said he was free this weekend so will get him to do the heavy lifting. Will try to get all the bolts and stuff out of the way in the next few days.

Went to the hot rod shop, they sold the heads with the stainless-steel valves, but he has a set just rebuilt for a customer, that he feels the customer may just sell and get aluminum for his hot rod. This one has normal sized valves and harden seats. A rebuild on my heads will take several weeks so I hope these are a go! Glad it is Iowa, some hot-rodders here still like that 350 Chevy engine over the LS. The shop does do a lot of LS work, but a few guys still like the 350 I guess.