no im not a fan of 1641's!!!!!!

[RICH-I-AM]

Ok where to start....
Baught my pride and joy in 2008 and due to one thing and another the engine died.
Stripped and rebuild (by myself) at the cost of almost 700 pounds, it had everything except barrels n pistons but did get rings.
Anyway i ran the engine in and even drove from Bedford to north wales and back again in a day with no problems :mrgreen: .
Then with a quick look over i noticed a hairline crack in the block about 3/4 of an inch long :? .
Removed the motor and stripped for a 2nd time.
Sent the offending 1/2 case to the engineers and had it welded (awesome weld done btw)
This was last year. Went to Action for the weekend and spotted a set of 1641 B&P's for sale, happy days i thought . They were cheap which made me wonder but baught them from a well known VW parts trader.
I did ask why so cheap? Show price apparently.
Built the engine again, now to 1641 spec.
Refitted and started to run it in again.
Dodging the rain drops i did about 10 miles a week every saturday pm.
It got to 60 miles and got a little tappet noise on no 1 cylinder.
So reset ALL the tappets and changed the oil, 20w 50 mineral.
Went for a spin and all the tappets were noisey!!!
Started questioning my own abilities being ive been a mechanic non stop for 20+ years now.
Anyway i went for a spin and ti turned from a rattle into a fierce knocking.
Asked a few questions in technical about deck height etc but knew damage had been done so for the 3rd time the motor came out and the heads and barrels removed.
Before removing thePnB's i chrecked the deck height and 3 were within the limits.
And no valve contact at all.
No 4 cyl had 3 mm clearence :shock: .
Upon stripping the barrels this is what i found :evil:

The piston was in one piece (just) but had a huge split running from the pin hole down to the edge of the skirt.
It was broken away as the pin was jammed and i tried to save the connrod, to late :?
Dont know why this happend, everything was tight and fitted correctly and now i dont realy care.
Luckily ive soursed a set of new rods and still have the original PnB's.
So should be up n running in a few weeks :mrgreen: .
Back to 47 HP and happy with that

Rich

 

[RICH-I-AM]

P.S these barrels and pistons coverd a total of 63 miles :roll:

Rich

 

[Dirty Harry]

:shock: :shock: whow.
What make were the pistons and barrels, did the pistons have a black graphite coting on the outside?

 

[PetrolHead]

Ouch :shock:

What do think failed first - the gudgeon pin or the piston?

It looks difficult to tell - pin could have failed, causing the piston to follow suit - or vice versa.

Eitherway it's not your typical 1641 based failure - which is usually overheated & warped thin-walled cylinders.

Could have just been unlucky and had an internal imperfection in the casting causing a weakness

Good luck with the rebuild.

 

[strongy]

i had a simler prob about 3 years ago.sounds identical,i took the engine out and dumped it in the corner of the workshop and its still there.not got round to striping it yet,prob should sell whats left of it, as it had new main bearings,new barrels pistons and heads and has only done about the same 60 miles.now uve jogged my memory i might have a look

 

[RICH-I-AM]

Not sure of the make of them, il take a look at work tomorrow to see if i still have the box they came in.
Didnt come with a graphite coating on.
Looks like the pin broke first wich put pressure on one side of the piston causing the fracture.
Not sure realy.
Pretty glad the damage was limmited to only one corner though.
Dont think the engine ever managed to get hot enough to test the cylinder wall thickness :shock:

Strongy, let us know how it goes?
Interesting stuff.
Did you have oversize Barrels n Pistons?

Rich

 

[Slammed]

My 1641 lasted fuck all miles before the piston broke just like yours last year. I'm think I may be crap at building engines though.
But mine came in a red box.

 

[Dirty Harry]

Was the arrow on top of the piston pointing towards the flywheel?

 

[K@rlos]

My friend Dan had a nutty 90 HP 1641 in the back of his 59 bug, he got through 3 sets of barrels and pistons. He gave up and put a 1300 single port in it after that haha!

 

[RICH-I-AM]

Was the arrow on top of the piston pointing towards the flywheel?

Yep.
Everything was done properly.
All gugeon pin clips fitted, Big ends torqued up properly, head bolts all correct and deck height all around the 1.7mm.
Cant see realy what caused it.
Someone who looked at it today seems to think the pin gave up 1st.

Sorted all the bits to do the repairs now n should have everything by the end of play saturday.
Blew the dust off the original BnP's today :mrgreen: but will need a thorough clean before refitting.
Just looking forward to getting it done now so i can take it for a spin

Rich

 

[vwvanman0]

Phew,

thought it was just me that had trouble with 1641s,
got rid of a 1600 that ran for miles with no trouble for a completely rebuilt 1641,
fitted correct tin and seals,even though the 1600 seemed fine without em,

result of my hard work/expense,

3 engine out/rebuilds in 3 years,the last left me stranded by the autoroute in france with a rod poking thru the case!

not having another,ever :lol:

 

[RICH-I-AM]

Showed an engineer the piston today.
He said that its the poorest quality material he has ever seen that is used to make a piston :shock:

Stock 1600cc for me from now on.

Rich

 

[r73]

i'm in the process of building a 1600TP out of a couple of spare engines - i do need to replace the B&p's and heads at least. I was going to go with Mahle forged (about £200 i think) and the heads from TES - I am tempted (if i hd more money :? ) to get more from TES though. Short block £419 long block £719 - what do you guys reckon - whats the best recomendations for parts? I wont really know the state of play till i split the case.

 

[surfbus]

I'm running a 1641 cc and had no real problems so far since 2007.. It was build in Holland....

 

[strongy]

just striped my engine down removed heads barrels and pistons and there all perfect (they did only do 200 miles tho).i have a prob with the con rod on number 2 it moves about on the crank :? my knowlage on engines isent too good so havent got a clue how that happend ??.at least i can sell the 1641 pistons barrels and the new heads as ther all like new

 

[andy11]

OMG wot have I bought !! :shock:

 

[Dirty Harry]

OMG wot have I bought !! :shock:

Relax, there is nothing wrong with 1641 barrels/pistons.
When everything is in good working order they last forever, friend of me has hit the 100.000 km mark with them (mahle cast)
Take a brand like Mahle or Kolbenschmidt and your save.
Even volkswagen had 2 over size pistons 86 and 86.5mm and this was designed to work under extreme conditions in use all over the world.
So we now take a 87mm set in our hobby cars and it would be shit :roll: :?: