1972 LT-1 numbers questions

[Ed H.]

Re: 1972 LT-1 numbers questions

Christian, I should be able to get you photos tomorrow (Tuesday).

[Christian R.]

Re: 1972 LT-1 numbers questions

Joe,

Thank you for this information.

I've thought the double nuts are here for adjusting and block the adjustement of rockers : it is possible ? This goes perhaps with the SERVIVE heads ? It is like you said : as long the engine runs well...

I've another question :

My AC had broken during my return trip from buying....
The compressor was really hot and smells burnt... (maybe the clutch ?)

I would like to do a complete revision of the compressor and, if possible, convert it to R134.
I've read somewhere that it is mandatory to change other elements.

Maybe it is the moment to inspect all major components of AC for a trouble free operation. The AC seems completly original.

Do you know where I can send my AC for a rebuild of it (and not a replacement, because I want to keep the original one !)

Regards
Christian

[Joe L.]

Re: 1972 LT-1 numbers questions

Joe,

Thank you for this information.

I've thought the double nuts are here for adjusting and block the adjustement of rockers : it is possible ? This goes perhaps with the SERVIVE heads ? It is like you said : as long the engine runs well...

I've another question :

My AC had broken during my return trip from buying....
The compressor was really hot and smells burnt... (maybe the clutch ?)

I would like to do a complete revision of the compressor and, if possible, convert it to R134.
I've read somewhere that it is mandatory to change other elements.

Maybe it is the moment to inspect all major components of AC for a trouble free operation. The AC seems completly original.

Do you know where I can send my AC for a rebuild of it (and not a replacement, because I want to keep the original one !)

Regards
Christian

Christian-------


There's no reason, at all, why SERVICE heads would require double nutting of the rocker nuts. It's just someone's idea of a way to provide locking of the rocker nuts. I've never seen it done before, at least with stock-type rocker arms. Perhaps, someone thought that this would be a more positive way of locking. The best thing to use for stock rocker arms are stock-type lock nuts.

I don't have any information on your AC questions.

[Michael W.]

Re: 1972 LT-1 numbers questions

I've thought the double nuts are here for adjusting and block the adjustement of rockers : it is possible ? This goes perhaps with the SERVIVE heads ? It is like you said : as long the engine runs well...

All Chevrolet overhead valve engines are adjusted via the nuts (or similar) on the rockers, irrespective of whether the engine has hydraulic or solid lifters. Some previous owner chose the unusual double nut arrangement on your engine. No idea why.

[Terry M.]

Re: 1972 LT-1 numbers questions

All Chevrolet overhead valve engines are adjusted via the nuts (or similar) on the rockers, irrespective of whether the engine has hydraulic or solid lifters. Some previous owner chose the unusual double nut arrangement on your engine. No idea why.

I can tell you why.

Back in the day when solid lifter SHP small blocks were daily drivers the valve train would get noisy after about 3000-5000 miles of operation. Readjustment of the rockers quieted the valve train for another 3-5k miles or so. Some folks thought double nutting or the use of taller rocker nuts with a set screw in the end lengthened the time between rocker adjustments.
We won't get into the need for frequent spark plug changes brought about by Chevrolet's specifications for too cold spark plugs.
SHP engines took a lot of maintenance to keep them running right. If you want to play, you have to pay.

[Joe L.]

Re: 1972 LT-1 numbers questions

I can tell you why.

Back in the day when solid lifter SHP small blocks were daily drivers the valve train would get noisy after about 3000-5000 miles of operation. Readjustment of the rockers quieted the valve train for another 3-5k miles or so. Some folks thought double nutting or the use of taller rocker nuts with a set screw in the end lengthened the time between rocker adjustments.
We won't get into the need for frequent spark plug changes brought about by Chevrolet's specifications for too cold spark plugs.
SHP engines took a lot of maintenance to keep them running right. If you want to play, you have to pay.

Terry------


In my opinion, the absolute best nuts to use on the rocker arms are the factory-type lock nuts. In fact, I really wish they could be used on roller rocker arms instead of the set screw locking type. Unfortunately, they cannot. However, the lock nuts can lose some locking ability over time. When that happens, the best plan is to replace the lock nuts.