1927 Buick Master Cam Timing Diagram

[dibarlaw]

My friend who is in the midst of rebuilding his 1927 engine has been studying his timing diagram he has concerns about errors on the duration of valve opening and closing. Or was that just how they designed it.

He was the person who bought the 1925-49 cobbleation with a variety of changes including a 1927 engine, radiator, headlights, a 1930s style top and bad body wood. But it did have wire wheels. He is turning it into some sort of Speedster. 

 He is rebuilding the 1927 Engine and is stumped by the cam timing. He has had it reground and new aluminum pistons. He has been studying the timing diagram for the 1927 and is concerned things are not correct. I do not have reference to the 1927 diagrams. I only have the 1925 Standard and Master diagrams. New computer here so my scanner has not made friends with it yet so I do not have a scan of my diagrams for comparisons.

I thought I would post the question on the forum for him.

 

 

 

 

Edited April 25 by dibarlaw
Added content (see edit history)

[Lee H]

Here’s the spec, at least for the intake valve. Is the problem that the intake is opening before TDC? It’s quite possible that the cam regrinder put a generic, or more modern grind on it, and having the intake opening some number of degrees before TDC may be the intent.

[Hubert_25-25]

Larry, 

     Attached are the pages about setting the valve timing.  The first 4 pages are from the 1926 Buick Export manual. 

In essence, valve timing is correct and checked by

a) putting a piece of paper in the #1 inlet valve gap area where you check with a feeler gauge. 

b) Put slight tension on the paper.

c) Another person Rotates the engine slowly.

D) As soon as the paper is let go.  Stop.  The engine should be on the 1-6 line or less than 1 flywheel tooth width before (above) - the 1-6 line is just below the center mark in the timing window.

I am also assuming that someone put the flywheel on correctly and 1-6 is TDC for the engine on #1.  I have known engines to have been assembled with the flywheel on the wrong bolts.     

 

This is the page from the 1925 Buick export manual.  Same instructions.  So you can use what you know from your engines. 

This is the layout on my 1925 Buick Standard.  I do not know if the teeth count is the same for a Standard and a Master, as the crank and camshaft gears are different sizes.  The final check is the paper check on the #1 intake valve.      Hugh

 

Edited April 25 by Hubert_25-25 (see edit history)

[32buick67]

From the Buick 27-4x manual, 120" WB:

 

 

[dibarlaw]

Thanks all:

 I will forward to Rob.