Do Briggs V-twin engine have valve seat problems?

[Fordiesel69 269]

Like the onan engines, do the briggs twins have the same issue with valve seats loosening up?

[Kelly 1,031]

The older L head briggs twins did, but I have never heard it being a issue in the V twins.

[Fordiesel69 269]

This would be a more opposed twin like in the 1980's. Not in a v config.

Which seat would loosen and what were the symptoms?

[Kelly 1,031]

Ok your title said V twin, I've had a few that the seats came out, on the old flat heads, two was the exh. seat, one was a int. I only had one running it popped and ran like crap, the others came not running with heads off and the valve seats hanging on the valve.

[Don1977 604]

I ran a Briggs Vanguard 16 from 1990 to 2010. What killed it was low on oil. I went off a bank and broke one corner off the oil pan. Had it welded back ran it for years until it open up a crack and dumped the oil out.

[buckrancher 2,694]

a co worker of mine lost a exhaust valve seat on his v twin last week the old mouse nest in the blower housing

Brian

[Fordiesel69 269]

So I read on here and on other engine forums that the onan twins require frequent valve lash adjustment. Do the briggs L head twins also needs this?

Why do the onan go out of ajdustment. My kohlers are NEVER out of adjustment. I know some engines the valves need to be ground down as there is no adjustment.

[Bow_Extreme 545]

Onan engines have an aluminum block and steel valve seats. The expansion and contraction rates are different between the two materials. The engines are air cooled and surrounded by sheet metal. This sheet metal can trap debris in the cylinder fins. The rear side of the engine is blocked in more so than the front side.

Bottom line, If you don't keep your Onan clean and serviced more than likely you will have valve issues. It's a great engine with all kinds of power and torque, rather expensive when it comes to parts and rebuild.

[Fordiesel69 269]

I am asking about a briggs L twin. I own 2 of them. I want to know if I also need to service the valve lash as frequent as on onan.

[Rooster 191]

I am asking about a briggs L twin. I own 2 of them. I want to know if I also need to service the valve lash as frequent as on onan.

Nope!

Once you set the lash it should stay! Setting the lash on them is a pain though....you have to grind the valves to set it. Which entails installing and removing the valves multiple times.

Briggs twins had valve seat problems on some of the older models due to a poor cooling arrangement.

They redesigned the tins on the engines and the problem pretty much went away.

You will get most of the problems on the #1 cylinder, due to some of the fins being machined down for starter clearance and the starter restricting air flow. #1 will almost always run hotter than #2. Many have mus-diagnosed this as a lean condition in the cylinder which is not the case.

That also invariably ends up being the cylinder stuck behind tin work of some type on the tractor!

On your Briggs opposed twins, I suggest turning the governor up to about 4K, they will actually run cooler and have a noticeable power gain. The increased power "lugs" the engine less and the increased RPM's move more air, both keeping the engine cooler.

[Fordiesel69 269]

4K on all aluminum. Sounds interesting. They sound scary at 3600, I wonder what 4000 would sound like.......................

[Rooster 191]

4K on all aluminum. Sounds interesting. They sound scary at 3600, I wonder what 4000 would sound like.......................

All aluminum??

Not sure what you mean there?

And I can tell you what 7000 sounds like on a Briggs Opposed, lol!

ALso the opposed engines are much more balanced than a single or a V-twin, the increased RPM is not really scary at all.

Though when you get into the higher performance builds, the opposed are not high rev engines, they build low end torque much better than they build high end power.

[Fordiesel69 269]

4K on all aluminum. Sounds interesting. They sound scary at 3600, I wonder what 4000 would sound like.......................

All aluminum??

Not sure what you mean there?

Aluminum in block, heads, cylinder walls.......

I have no prob bumping it up a bit to 4k, but will that increase overall wear?

[Rooster 191]

Ahh..

Most of the opposed twins are cast iron sleeved bores, there were some "cool bore" engines that you do want to stay away from.

As for wear, not really, I have run them at that speed for years.

Alot of racers turn aluminum block engines much tighter than that...8000, 11,000...13,000!!!(No joke, on a kohler V-twin!)

I have built low budget race engines with stock rods and parts that held 5k just fine.

[Fordiesel69 269]

Mine is the following:

Model 402417

Type 066501

Code 82042912

Any idea if this is a cool bore? It does not say I/C on it so I do not beleive it is a cast bore. I have never had the head off, but I know it has less than 1000 hrs.

I just tore the shrouds off and cleaned the fins. Nice and dirty. So im glad I did...........

[Fordiesel69 269]

So, anyone know if this is a cast iron sleeve engine or "cool bore"? It is not tagged "I/C" anywhere on the decals.

[Rooster 191]

That'll be a cast Iron Sleeve engine.

I don't know that they made the 40 Cube in a Cool Bore?