Burnt valves???

[jagarra]

Hi,
I am a new member without a truck yet, but I do have a commitment to get one from a friend of mine. It is a 64 or 65 Fleetside with the V6 and 4 speed, SWB. It does not run right now and I am being told that it has burnt valves from unleaded gas being used.
The burning question is, is that problem common or is he mis-informed?
when I get the old darling home I plan to do a compression test to see how solid that area is, but I was just wondering if unleaded gas is an issue.

I have been working on cars since I had one, about 52 years so I do have some experience in repairing many items. I current have a bunch of old Jaguars and a 52 Willys Aero Ace couple that my grandfather bought new.

Looking forward to discussions problems and sharing this new iterest for me.

regards,

gerard

[BarryGMC]

I have had dozens of those v 6 gmc engines. I have never seen any evidence of seat erosion from unleaded Gas. I have seen valves burnt from not enough lash quite a few times. I will add I rebuild engines regularly. I have a full machine shop with two head mills. Plus everything else. Hardened seats take an hour or so and some engines require them. But I have never done them on a v6. Even a turbo 305 running 12 pounds of boost with some really high EGT numbers has been fine. Check the lash and then compression test. Barry.

[jagarra]

Barry,

Thanks for the advise. I figured something else may be at fault. Any idea what to statically set the valves when cold. My book says to set them .012 on the intake and .018 on the exhaust when engine is warm and idling slowly. A feat kind of hard to do on an engine that may not start.
I am not sure if I should compensate for expansion by reducing the lash or increasing it.

thanks,

gg

[FetchMeAPepsi]

Hi Jagarra and :welcome: to the club! For cold, you should add 0.002 to the lash, but really you need go back and set them hot for a better running engine. You won't burn yourself up or burn your house down, just take it around the block a couple of times till it gets warm.

[jagarra]

Going to check out the truck again this afternoon. My friend, was telling me the symptoms were that the truck was losing power, not running properly over a period of time, until the point where it would not start.

Of course this information is 2nd hand as he got the truck from the widow of another acquantence, as a non running vehicle.

Could be zero valve lash, or something a bit more complicated.

[FetchMeAPepsi]

Get some pics. For no other reason than that we love pics here :D

You might take a movie too so you can remember how it sounded, how it looked, and anything that might be out of place. We can help with that and more details. You might have one of those where you pay $500 for the old "dead junker", swap the battery and drive away while the PO scrapes his jaw off the ground in your rearview mirror!

:lolsmack2:

[jagarra]

I went over to check the truck out a little better Monday. Body is pretty straight, the usual rust in the lower corners of the front fenders. The wood in the bed really needs some help. probably replacement will be the answer. Glass is good, engine compartment looks all complete with not a lot of any hash work done to it. Interior is good condition, just needs a good cleaning.
Wheels are after market, chrome spokes ones, will keep those, he has the stock split rims if I want them. May pass on those as I remember changing them when I worked in a sevice station in the 60s, not too bad, you had to be careful when you inflated them up to insure the ring was seated properly.
So far for the money he is asking the truck will be a good project, like I really need another one.
The trim strips on the door are both damaged, I think I have a question about those as I was looking on vendors sites that sold replacements, seems some had a single strip while other had a double with another thinner one on the lower portion. Milage on the odomater was 67K, not too bad. Found out that the PO before the one I am talking too had 2 of these trucks, this one which he used as a work around the place one, going to dump and such. The other which has been garaged since new and was used very little.
Forgot to take pictures, my bad, will take some when I drag it home.

gg