Heymow - Lawnmower Racing Forum

Engine Help => Briggs Flathead => Topic started by: JGC403 on March 13, 2018, 11:01:31 pm

Title: Briggs 40ci Engine specs
Post by: JGC403 on March 13, 2018, 11:01:31 pm

I'm having a difficult time trying to find engine specs on these engines.  The specs I'm looking for aren't published or they aren't consistent from different places.

Engine ID 402417  0660  01

Bore: 3.438"
Stroke: 2.156"
intake valve lash: 0.005"
exhaust valve lash: 0.008"

I need:
connecting rod length
compression ratio
Intake and Exhaust valve diameter
Intake and Exhaust valve steam diameter
Stock camshaft specs:
-valve lift
-duration @ 0.050"
-LSA
-degreed centerline
-exhaust port length

I would appreciate any info I can get.

Title: Re: Briggs 40ci Engine specs
Post by: PJG56 on March 15, 2018, 09:34:16 am

Just curious,do you have this engine you want all therse specs on???

Title: Re: Briggs 40ci Engine specs
Post by: JGC403 on March 15, 2018, 03:02:42 pm

Yea, haven't torn it apart yet.  Most of the information I need i can get once I pull it apart, was just hoping someone already new most of the answers.  The camshaft specs will take some time to figure out, but I think I can do it with a degree wheel and dial indicator.

Title: Re: Briggs 40ci Engine specs
Post by: PJG56 on March 15, 2018, 05:27:19 pm

If you know how to use a degree wheel you can,but not sure why you need all the stock info

Title: Re: Briggs 40ci Engine specs
Post by: JGC403 on March 15, 2018, 07:21:08 pm

I have exhaust header design software.  All of the above info is needed for it.  I have seen a couple threads on exhaust length and diameter, trying to see how close those are compared to the software. 

Title: Re: Briggs 40ci Engine specs
Post by: PJG56 on March 16, 2018, 08:44:08 am

If I remember right,the couple of stock cams I maped out a number of years ago were 225 dur@.050 lift and around .290 lift if not mistaken and LCA was like 114 I think ,this was a 42ci cam