DOHC CAM INFO

[napatiger]

Hey guys I am trying to get a blueprint from my machinist who did two 'go-fast' rebuilds of the LQ1. Including regrinds from a guy who did Porshe stuff.

But here is some usefull info in the meantime....

From AERA (American Engine Rebuilders Association)
For 1991 - 1997 GM 3.4L Vin X engines. This engine uses a dual overhead camshaft (DOHC) design with four different camshafts per engine. Making sure each camshaft is marked prior to disassembly is crucial to reassemble the cylinderhead correctly. ....We all know that.....

..interesting part....
To further complicate the rebuilding process, there have been fourteen different camshafts used for the engines. Aftermarket camshaft suppliers have been reluctant to supply camshafts for these engines as so many variations are used. Inter-mixing of different year camshafts is not advised as lobe configurations vary. In some, but not all, instances camshaft casting numbers can be used to assist in identifying each cam.


1991-93
RIGHT SIDE
EX-CAST# * PART# * IN CAST# * PART#
1038 * 10130914 * 1036 * 10130912
LEFT SIDE
EX-CAST# * PART# * IN CAST# * PART#
1037 * 10130915 * 1035 * 10130913

1994
RIGHT SIDE
EX-CAST# * PART# * IN CAST# * PART#
NO INFO * 24503216* NO INFO * 24503212
LEFT SIDE
EX-CAST# * PART# * IN CAST# * PART#
NO INFO * 24503217* NO INFO * 24503213



I though that was pretty interesting seeing how the profile changes so much.

I have different casting numbers....95
2188 sshit I forgot if intake or exhaust. Anyways I marked them before disassembly.

What is your casting number?

[Mach10]

Just because the castings were different don't necessarily mean the lobe profiles are that much different.

In any case, GM is so inconsistant with it's manufacturing process as it is, I wouldn't be surprised to see more variation between individual cams of the same casting than what you would measure as an average over two casting runs.

Don't forget, some LQ1s were assembled in different places. Detroit and Quebec IIRC. Probable that they used different casting numbers to track where they were from?