Briggs 17HP Twin Intek - Broken Rods

[Tinkerer200]

If you search you may find a picture of the chewed up pushrod from my Intek in this forum. The part that went down the flea hole into the digestive track was broken like yours, but also had a lot of nibble marks where the gear was tasting before biting. :laughing:

While this does happen occasionally most of the time the push rod is simply lying there waiting for someone to invent a way to fish it out. I tried. I have also thought of putting a screen in the drain hole to prevent push rod from going down as a preventive measure.

Walt Conner

 

[motoman]

Walt, and a confession I made once before....when the engine was apart the first time with a pushed guide and rounded exh cam I thought. "How sloppy of the casting house to leave a spider web over that oil return hole. Here , let me open it a little to help with oil return." Probably was there on purpose to inhibit the pushrod as projectile. Who'da thunk?? But I still wonder how that whole bloody pushrod was launched completely into the sump. Perhaps it jumped out of the lifter recess and the rocker return launched it through the bullseye. Or maybe once the tip reached the timing gear it chewed, swallowed, chewed,swallowed? :licking:

 

[Tinkerer200]

I don't think it is a matter of launching, I think vibration causes the push rod to work its'way thru the drain hole. All I have had were intact when removed from the sump.

Walt Conner

 

[ILENGINE]

Of the last three pushrods in the crankcase jobs that I have done, I have had one bent but still in on piece in the sump, one broken into pieces in the sump, and one wrapped around the camshaft.

 

[motoman]

One final word on my one event. ( I see now it is a pattern-Briggs are you reading this?). When my pushrod entered the sump I was mowing uphill with full grass baskets. That says high demand on Intek so I think the engine was running on both cylinders or it would not have been performing. Suddenly a loud "ka-ching" and I immediately shut down. Does't seem to have been enough time for movement of the pushrod via vibration. This is a reallly odd event not to have been designed out by the engine designers. What a trip. :laughing:

 

[Tinkerer200]

The steel pushrod (Exhaust) is used on the exhaust side due to the amount of heat it can endure compared to the aluminium push rod (Intake). So always make sure that each push rod goes to its corresponding side should you ever take apart the valve train.

-Jeff

Well actually it has to do with expansions and contracting. B&S uses an aluminum push rod on the valve involved in compression release. On Intek it is on the Intake valve because the Intake Valve is used for compression release. On Vanguard V twins the Exhaust Valve is used for compression release and an aluminum push rod is used on the EXHAUST valve. Some people are substituting a steel push rod for the aluminum and seem to do OK. When an aluminum push rod bends it is because there is a problem you need to find and solve. Many times it is because a valve guide has slipped up and that because of a cooling problem, plugged cooling fins and or cooling shroud. Sometimes it is because a valve is sticking. Top cylinder lube is called for then.

Walt Conner

 

[Tinkerer200]

With all due respect brother I work at the VTwin plant and the aluminum pushrods that go into our Vanguards also reside on the intake side. Steel pushrods can still be found on the exhaust side.

Japanese Vanguards used aluminum push rods on the EXHAUST valve which relieved compression and steel on the Intake. As a B&S expert you should have been well aware of that, check the Service Manual. What you guys did after moving production to the US, I have no idea.


"Install Push Rods
NOTE: All models except 540000, 610000 –
Exhaust valve push rods are aluminum.
Models 540000, 610000 – All push rods are
aluminum."

Sort of shots down your theory. Section 6 Page 124.

Walt Conner

 

[Tinkerer200]

Well seems I have learned something new also. I would be very much interested in the model number(s) of US made V Twin Vanguards using aluminum push rods on the Intake valve AND the Service Manual number for such engine. Also, does the US made Vanguard V twin relieve compression using the Intake valve or the exhaust valve? Is it a true Vanguard or a warmed over Intek V twin which does relieve compression via the Intake valve?

Thanks for any enlightenment.

Walt Conner

 

[Tinkerer200]

I will look into that for you. The Vanguards we manufacture here are the 810cc Vanguards. Both Carb and EFI models. I wanted to double check with a few other sources about the push rods. According to them, it is due to the expansion of heat and the steel is used to prevent the valve lash from changing like mentioned before. With it being much cooler on the intake, the aluminum is used. We are not sure why the Japanese made Vanguards have aluminum push rods for exhaust since we do not make them but we believe they are much larger and beefier than the ones we utilize. We would have to get an answer from a product engineer that calls that plant home. I don't want to argue, just want to make sure the right info is put out there. If you could, do you have supporting documentation showing that the aluminum is on the side of whichever the compression release is to be performed?

I attempted a previous reply but since I do not see it here, I will try again. I said besides my personal experience working on them, I will send you a Service Manual but do not believe this site supports that so if you will contact me at this address - wconner5 at frontier dot com - I will be glad to send it to you. Put address in proper format and remind me what you want. I get a lot of requests and have a poor memory. I would appreciate a Service Manual for the V twin Vanguards you make in return.

It has been my experience that cell phones may not accept a file the size of a Service Manual.

Walt Conner

 

[Tinkerer200]

"From what I have been telling you from the start, the steel handles the heat better and does not expand as much so it prevents a drastic change in valve clearance, which is why it is found on the exhaust side. Guess I am still a Briggs expert after all."

You did read the excerpt I sent from the official B&S Vanguard Service Manual and I offered to send you the complete manual not have you go searching around some place. B&S does not give away Service Manuals you know.

Folks, when in doubt of what you read here, check the B&S Service Manual.

Walt Conner