Export thread

33R877-002-C1 170227ZD
Craftsman 917255830 (t2500)

While researching about my mower, I found a lot of talk online about that the 330000 series OHV is prone to the head gasket blowing out at a specific place every time, example pic attached.
I'm wondering if this is due to user error or if it is due to bad engineering?
I'm not experiencing problems but I was wondering if it's smart to pre-emptively replace the head gasket or just leave it alone til it breaks?
I checked the oil to see if my previous carb may have leaked fuel into the crankcase. Oil didn't seem too runny but it did have a slight odor of what i'd describe as 'exhaust'. It didn't strongly smell of gas. Maybe this was dumb but I wiped down the dip stick except for the bottom and tried lighting it on fire away from the machine with no success.
I'll test compression tomorrow for good measure.
I purchased the oem gasket kit just in case, supposedly it has been redesigned to be thicker in the area it usually fails at.
I also downloaded the briggs workshop manual (PN 27681) and am aware of the basics like using the sequence to torque the head bolts and to do it in two steps, also have torque wrench.

Just keep a head gasket on the shelf is good enough.
The intek range was a copy of the Japanese designed Vanguard range and when it was done they make a dogs breakfast of it.
Too little metal on the bridge , too thin a head at that position & not enough clamping force.
The bolts nearest to the pushrod tunnel should be a little closer to tunnel , or been a bit bigger or had a large high tensile washer under them or an extra bolt at the tunnel .
Most are OK so if I was to be asked for a QC investigation, I would be looking at the casting carousel very closely plus the pouring furnace temperature control.
Some engines sail on forever while others are always blowing gaskets.
For problem ones I fit copper gaskets from Lanni@coppergasketsUS that are touch thicker than the B &S ones . lightly face the head & barrel and they never come back

The Head gasket issue isn't limited to the 33 series, It involves all the Intek vertical from 21 to 33 series engines . Like Bert mentioned, just not enough meat between the cylinder and the pushrod cavity. If they had engineered it with a bolt in the push rod cavity this problem wouldn't exist. Then you add in the warped heads and in some cases warped blocks just makes the issue worse. I have even had a few that you could see and feel the chatter marks from the milling machine on the block surface. Looked like a file magnified 1000 times.

Copper Gaskets Unlimited​

515 E. Carfree Hwy #673 Phoenix AZ 85085

coppergasketsunlimited@yahoo.com

623 340-4300

ILENGINE said:

The Head gasket issue isn't limited to the 33 series, It involves all the Intek vertical from 21 to 33 series engines . Like Bert mentioned, just not enough meat between the cylinder and the pushrod cavity. If they had engineered it with a bolt in the push rod cavity this problem wouldn't exist. Then you add in the warped heads and in some cases warped blocks just makes the issue worse. I have even had a few that you could see and feel the chatter marks from the milling machine on the block surface. Looked like a file magnified 1000 times.

Click to expand...

Not sure is it is deliberate but all of the latter models have had rough machined heads.
Triumph did this on the tripples at one time to stop the head gasket extruding out the sides , again the sealing surface was too thin, so I thought the rough finish was deliberate.
Weather it is on not it does make cleaning off all of the old gasket a chore .

Thanks for all the info and for pointing me towards the copper gasket, fellas.
May just return this briggs gasket set and buy the copper one. Atleast then my money will be going to a real US craftsman instead of briggs.

bertsmobile1 said:

Not sure is it is deliberate but all of the latter models have had rough machined heads.
Triumph did this on the tripples at one time to stop the head gasket extruding out the sides , again the sealing surface was too thin, so I thought the rough finish was deliberate.
Weather it is on not it does make cleaning off all of the old gasket a chore .

Click to expand...

The ones that have come into the shop looked like the surface mill was just a portion of a degree off level with the block and creates concentric circles across the top of the block.

I would also be checking either head or cylinder warpage if not both. The blowing of head gaskets seems to be worst with the 310000 series over the 330000 series; although, the 21 28, 31, and 33 all use the same style gasket for thier cross flow heads.

Copper Coat works well on steel shim head gaskets, if the block or heads have a course look after milling. I've used it many times drag race engines. Should work on composite gaskets also.

Apologies for the delay gentlemen, update:
Contacted Lani from CopperGasketsUS. He informed me to place an order on their site or ebay and include my engine number. Will be installing it in the near future.

In regards to the poor milling/surface on head: any suggestions on what tool(s) I need to use to inspect/measure whether or not it's level and in spec? I haven't done measurements like that before and wouldn't mind buying a new tool if needed, heh.

A bit of a rub on a sheet of 600 wet & dry on a sheet of glass.
Probably need a few sheets.
Head is easy block is a bit more tricky
make sure the copper gasket is dead soft when you get it.
If it is dead soft rolling your thumb nail across it should leave a crescent indentation
If not anneal it

Florida said:

Apologies for the delay gentlemen, update:
Contacted Lani from CopperGasketsUS. He informed me to place an order on their site or ebay and include my engine number. Will be installing it in the near future.

In regards to the poor milling/surface on head: any suggestions on what tool(s) I need to use to inspect/measure whether or not it's level and in spec? I haven't done measurements like that before and wouldn't mind buying a new tool if needed, heh.

Click to expand...

I second the plate glass and wet/dry sandpaper idea. I used to use the glass garage door.

Just removed a head off a 190cc Briggs L-head Toro Recycler. For grins I checked it on plate glass. Sure enough was not even close to flat. On this head, bolts are along the outer perimeter. That was where the distorted metal was. Ran across a sheet of 220 grit. Could of used 80 to start it was pretty warped.

From now on, every head is getting flattened. Bet most heads are not even close to flat.

slomo

slomo said:

I second the plate glass and wet/dry sandpaper idea. I used to use the glass garage door.

Just removed a head off a 190cc Briggs L-head Toro Recycler. For grins I checked it on plate glass. Sure enough was not even close to flat. On this head, bolts are along the outer perimeter. That was where the distorted metal was. Ran across a sheet of 220 grit. Could of used 80 to start it was pretty warped.

From now on, every head is getting flattened. Bet most heads are not even close to flat.

slomo

Click to expand...

not many level heads out there these days.

Scrubcadet10 said:

not many level heads out there these days.

Click to expand...

Some of us like to swim against the current LOL.

slomo

Cheers fellas, will check it out and report back