Slant *        6        Forum
Home Home Home
The Place to Go for Slant Six Info!
Click here to help support the Slant Six Forum!
It is currently Sat Nov 30, 2024 5:43 pm

All times are UTC-08:00




Post new topic  Reply to topic  [ 2 posts ] 
Author Message
PostPosted: Tue Mar 06, 2007 2:26 pm 
Offline
Supercharged
User avatar

Joined: Sun Nov 03, 2002 9:20 pm
Posts: 13060
Location: Fircrest, WA
Car Model: 76 D100
Hi gang, been awhile since I posted.

I am working on my brothers van (again) and have a question about the camshaft centerline.

The motor is a 225 out of a 76 Volare (forged crank) rebuilt using a factory 76 camshaft. When I put the motor back together I used one of the old MP double roller timing sets. Ever since the motor was built it has had poor gas mileage and poor power. Vacuum is down around ten inches and timing has to be pretty retarded to avoid pinging under load.

All of this leads me to believe the camshaft is installed a few degrees off from the correct setting. So, what is the correct camshaft centerline degree for a 76 stock cam, and would I get some low RPM power by advanceing or retarding the cam in any direction? I have never degreed a cam before so speak slowly. :)

Thanks.


Top
   
 Post subject:
PostPosted: Tue Mar 06, 2007 5:01 pm 
Offline
Supercharged
User avatar

Joined: Sun Nov 03, 2002 9:20 pm
Posts: 13060
Location: Fircrest, WA
Car Model: 76 D100
Okay, I think I figured itout. Duration = 244, intake opens at 16 BTDC. 244/2 = 122. 122 - 16 = 106. Centerline on a stock cam = 106 degrees ATDC.

It looks like the cam gear was misdrilled on the timing set since the cam is coming to TDC at 102 degrees.

I also took this opportunity to check if the vibration dampener timing mark had slipped and it had- the timing mark was retarded by 8 degrees.

I also dug around and found that advancing the cam timing is good for low RPM torque and performance, and that is what I am looking for since this slant is in a van.

So if the cam is centerlined at 102 degrees, isn't this already four degrees advanced? Should I get the cam gear drilled out and use one of the MP advance bushings?

Thanks for any suggestions. There is a good seal on the timing chain cover and I don't want to break it if I don't have to.


Top
   
Display posts from previous:  Sort by  
Post new topic  Reply to topic  [ 2 posts ] 

All times are UTC-08:00


Who is online

Users browsing this forum: Ahrefs [Bot], Semrush [Bot] and 4 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Limited