arrows on pistons

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philmcC
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arrows on pistons

Post by philmcC »

Reassembling liners and pistons in crankcase. I assumed the arrow on the pistons meant that they would face the crank pulley end of the crankcase. Having just gone through Haynes again it says that original pistons had an arrow pointing to the flywheel end. The parts I used were from Brickwerks aftermarket pistons and liners fitted together. Do I need to go back and redo?. I've only done one side, but it means taking the cylinder head off again which is a pain. Any thoughts.philmcC

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itchyfeet
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Re: arrows on pistons

Post by itchyfeet »

Interesting question, I don't know the answer but I'm struggling to think why it would matter.
I asked on a fb group for you.
Last edited by itchyfeet on 27 Jul 2018, 17:18, edited 1 time in total.
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bigherb
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Re: arrows on pistons

Post by bigherb »

You don't say what engine but, flat fours (AC and WBX) point to the front of the engine which is the flywheel end. The Gudeon pins are offset to stop piston slap and need to be the right way round.
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937carrera
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Re: arrows on pistons

Post by 937carrera »

bigherb wrote:You don't say what engine but, flat fours (AC and WBX) point to the front of the engine which is the flywheel end. The Gudeon pins are offset to stop piston slap and need to be the right way round.

^^^ What he said

Con rods are also directional and can be fited upside down
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itchyfeet
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Re: arrows on pistons

Post by itchyfeet »

yep same answer on fb WBX group
sorry off with your head
don't reuse compresion seals
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philmcC
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Re: arrows on pistons

Post by philmcC »

What a pain!. Took the head off and cleaned everything up. I don't think it would be possible to get the sealant off the rubber seal but will have a go. Ordered 2 new compression seals for the top of the liners. Motto read instructions 4 or 5 times, and assemble once!.
On a different tack I found out that the crankshaft pulley oil seal on a syncro is different. Comes in 2 parts. A sleeve for the crankshaft pulley which engages with the oil seal. Not cheap.philmcC

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bigherb
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Re: arrows on pistons

Post by bigherb »

philmcC wrote: On a different tack I found out that the crankshaft pulley oil seal on a syncro is different. Comes in 2 parts. A sleeve for the crankshaft pulley which engages with the oil seal. Not cheap.philmcC
Yes, they have an additional sand seal.
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multisi
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Re: arrows on pistons

Post by multisi »

philmcC wrote:What a pain!. Took the head off and cleaned everything up. I don't think it would be possible to get the sealant off the rubber seal but will have a go. Ordered 2 new compression seals for the top of the liners. Motto read instructions 4 or 5 times, and assemble once!.
On a different tack I found out that the crankshaft pulley oil seal on a syncro is different. Comes in 2 parts. A sleeve for the crankshaft pulley which engages with the oil seal. Not cheap.philmcC
I have a main seal that was only on an engine for a few miles without sealant, you can have it for postage only if you cant clean yours up, this one is a victor reinz type.
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philmcC
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Re: arrows on pistons

Post by philmcC »

Thanks for very kind offer. Had a go at cleaning it up, sliced finger and in a moment of temper ordered a new one. That dirko stuff certainly sticks. Does anybody recommend anything else to use other than that for the rubber gasket?.philmcC

philmcC
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Re: arrows on pistons

Post by philmcC »

Well it's one step forward and 2 steps backwards just now. Having put the pistons and liners in the wrong way round I had to remove the pistons from the liners. Bought a cheap ring compressor, and tried to put them back. Pretty useless piece of kit which was unable to compress the rings enough. Having tried gently to tap pistons in managed to break the middle ring and the oil scraper. New ones on order from Brickwerks. Found that if I used the ring compressor with a supplementary jubilee clip could get enough compression to make it work. I am learning on the job!.philmcC
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937carrera
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Re: arrows on pistons

Post by 937carrera »

First type 4 engine I did many years ago I just used a jubilee clip and grease to do the piston rings.

I have since graduated to a tool just like the one you have. Oil the inside of the tool, compress the rings and then slacken slightly so that you can slide the piston in.

Are you just using an allen key, or a bit with ratchet to tighten ?
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
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philmcC
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Re: arrows on pistons

Post by philmcC »

Yes it's an Allen key. I will be much more careful when I get the new rings with how much tensioning I do. The pistons and liners and compressor tool were all generously soaked in oil. Fingers crossed

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itchyfeet
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Re: arrows on pistons

Post by itchyfeet »

I have been advised that rear entry is easier but I prefer front entry

I get the compressor as tight as poss then with a rag in the top so I don't cut my hand and press hard and fast
go slow and it snags
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philmcC
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Re: arrows on pistons

Post by philmcC »

In my hands the ratchet piston ring compressor sleeve was a disaster. Broke 2 piston rings in attempt to get the piston in the sleeve. Decided to invest in tapered sleeve compressor which is made from a solid billet of aluminium Teflon-coated. Worked brilliantly 1st time round.
Taken about 3 weeks to get back to where I was!. That's learning on the job for you.philmcC
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937carrera
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Re: arrows on pistons

Post by 937carrera »

It al looks nice & clean though

:ok
1981 RHD 2.0 Aircooled Leisuredrive project, CU engine
1990 RHD 1.9 Auto Sleeper with DF/DG engine

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