intake lift rod not moving that much
- Thread starter Michael_Gee
- Start date
bertsmobile1
Lawn Royalty
Actually it costs a lot more to make a one piece forged camshaft than to make a built up one
The price would be least double if not more
A forged crankshaft in a motorcycle accounts for a touch more than 1/2 the entire cost of making the engine
This no doubt is why Kohler switched from a forged crank in the Command series to a cast malleable iron crank in the Courage series .
And once you start down the high volume low margin road there is no turning back till you get to the end , bankrupt .
So halving the cost price of a million cams is significant
Add to this B & S most likely buy the cams in so it is a case of he who supplies the best price gets the order
When B & S were a manufacturer rather than just an assembler then the cost of tooling comes into play
Once they become a bought in item it is the problem for the supplier not the purchaser
The price would be least double if not more
A forged crankshaft in a motorcycle accounts for a touch more than 1/2 the entire cost of making the engine
This no doubt is why Kohler switched from a forged crank in the Command series to a cast malleable iron crank in the Courage series .
And once you start down the high volume low margin road there is no turning back till you get to the end , bankrupt .
So halving the cost price of a million cams is significant
Add to this B & S most likely buy the cams in so it is a case of he who supplies the best price gets the order
When B & S were a manufacturer rather than just an assembler then the cost of tooling comes into play
Once they become a bought in item it is the problem for the supplier not the purchaser
Last edited:
Michael_Gee
Member
Sorry for taking so long to get back to you all. The grass was starting to slow its growth and so I was using my walk behind to take care of the areas that are still green (and get a bit of well-needed exercise)
So, the one that isn't moving much is on top and I expect it to be the exhaust, NOT the Intake that was incorrectly mentioned previously...and @StarTech caught
. I took my digital calipers to try to get an idea of how much they open.
Exhaust:
Low: 25.91 mm
High: 27.31 mm
The valve opens approx 1.4 mm
Intake:
Low: 27.40 mm
High: 31.85 mm
The valve opens approx 4.45 mm
Now, I guess it's possible that the intake and exhaust don't open the same amount and this fact is making me think this is the reason why power is dipping from time to time but.
So, the one that isn't moving much is on top and I expect it to be the exhaust, NOT the Intake that was incorrectly mentioned previously...and @StarTech caught
. I took my digital calipers to try to get an idea of how much they open.Exhaust:
Low: 25.91 mm
High: 27.31 mm
The valve opens approx 1.4 mm
Intake:
Low: 27.40 mm
High: 31.85 mm
The valve opens approx 4.45 mm
Now, I guess it's possible that the intake and exhaust don't open the same amount and this fact is making me think this is the reason why power is dipping from time to time but.
bertsmobile1
Lawn Royalty
Firstly valve lift is not a good measure unless you set all of the valve lashes identical
Resting ( fully closed ) height is what you measure to verify that the valves are seating properly & the valve guides have not shifted
You slip the rockers off the pushrods then rotate the engine to check cam lift to verify that the cam lobes are OK
AFAIK all mower engines use the same valve lift & same valve lengths so your measurements if they are correct show a cooked engine with soft heads that have allowed the guides to shift
SO it is off with the heads to check them properly .
Resting ( fully closed ) height is what you measure to verify that the valves are seating properly & the valve guides have not shifted
You slip the rockers off the pushrods then rotate the engine to check cam lift to verify that the cam lobes are OK
AFAIK all mower engines use the same valve lift & same valve lengths so your measurements if they are correct show a cooked engine with soft heads that have allowed the guides to shift
SO it is off with the heads to check them properly .
StarTech
Lawn Royalty
With both rocker set at zero clearance both rockers movement should be the same as the cam lobes are identical.
This zero clearance is when the valves are closed. But with the rocker clearance being at .003-.005 IN and .005-.007 EX they should be nearly identical with setting at zero; unless, you just want be nit picking.
Now back to my Strawberry/Kiwi drink and the party.
This zero clearance is when the valves are closed. But with the rocker clearance being at .003-.005 IN and .005-.007 EX they should be nearly identical with setting at zero; unless, you just want be nit picking.
Now back to my Strawberry/Kiwi drink and the party.