Technical Young one needing a hand.

[HamishNZ]

Hey,
I just bought a 69 500F and have poured every available minute in the shed sorting out the body work. I have just removed engine and the problems have started from there as I have little experience.
The previous owner had a full rebuilt completed 20 years ago and upon testing the engine wound down at idle and stopped. He has told me that the key holding the timing wheel to the crank dislodged under load because of no loc tite. I have removed timing cover and cam and crank wheels but am stuck as what to look for? An elliptical key means very little to me. Any light shed on this subject would be awesome. Would also really appreciate where to go after this regards to engine?
Any info is good info to a young guy who just wants his 500 on the road to be appreciated.
Thanks.
Hamish.

 

[Bambino]

Hi Hamish,

Earlier this year I wrote a short thread entitled '650 Engine Project' - I've bumped it so it now appears directly under this thread. Have a look through it as it contains some photos that may be of use to you.

Also, if you don't yet have a manual, have a look at the online Haynes manual in amongst the stickies at the top of these threads.

I'm assuming the part the po was talking about was the woodruff key (see photo). It fits on the front of the crankshaft and is there to maintain the timing relationship between the camshaft and crankshaft and no, you don't need loctite to prevent it falling out, it is held in by the front pulley. If it is missing (he may have lost it during the rebuild ), new ones are available.

Let us know how it all goes,
Chris

 

[tjmra]

Hamish,

a couple of thoughts that you may find helpful.

Take photos of eveything as you are pulling parts off, it will help when you are trying to work out how it goes back together again.

Get some self seal plastic bags from the supermarket and put the parts that you pull off inside. Write where the parts came from on a post-it note and stick that into the bag as well. Makes it a lot easier to find the parts when you need them. Identifying bolts can be difficult after they have been rolling around on your workbench for a month or so.

Aluminum is not very forgiving. Tightening bolts till the aluminium threads strip and then backing the bolt off half a turn is not a method that you should employ with your motor etc. It gets expensive after a while.

Don't ask me how I know all these things as it is embarrasing. Even now I go too fast and don't heed my own advice.

Get some rubber gloves from the supermarket. When you are cleaning years of muck from your mechanical parts it is a no brainer to pull the gloves off and bin then and have relatively clean hands.

Finally, don't put money on the All Blacks in the World Cup. Spend it on your car instead.


Regards


Joe R

 

[HamishNZ]

Hey guys,
Thanks for the replies it has been rather good advice,
I pulled open my manual and have completed dismantled the engine and am starting to clean parts in regards to woodruff key. It seems as though the woodruff was misplaced during the first rebuilt, can anyone tell me the dimensions of the key so i can find a suitable replacement.
Thanks and Joe after last nights game the all blacks arent looking to flash but its more exciting when you have something on the game. Definately will be an interesting time, most of it spent in the garage i imagine.
Hamish.

 

[Bambino]

Hamish,
Have a look here -

http://www.fiat500ricambi.com/fiat500/?categorie=Engine+parts&product=MO1207

I've bought a lot of parts from these guys (they are in Holland). They deliver promptly, take PayPal and seem like a reputable company.

There is a guy in Auckland who sells parts for 500s - I don't have his url at present but can find out for you.

There is also The Spare Place in Adelaide (AUS)
http://www.thespareplace.com.au/

and of course Mr Fiat in Atlanta (USA)
http://www.mrfiat.com/


Let us know how you go,
Chris

 

[Damon500]

Hi Hamish,

Good to see another Bambina about to hit the NZ roads again soon!
What part of NZ are you in? I lived in NZ for 20yrs and owned a dozen or so Bambini over there- i should still be able to help you find a key locally.

The job is pretty easy to do- should only take a couple of hours at an easy pace and there is no need for loctite on the key- it is held in by the front timing sprocket and front pulley.

Let me know if I can help...

 

[HamishNZ]

Hey guys,
finally decided to rebuilt the engine completely, the pistons needed soaking in liquid wrench for a week before they budged. My question is... is this piston still in a usable state? There is no damage to cylinder walls so won't need honing or anything. I am hoping just some new rings and a clean up will see me through.
Cheers guys.
Hamish.
Will post some photo's of progress soon.

 

[Damon500]

Hi Hamish,
Here are some of my experiences from rebuilding numerous Bambina engines during my student years in NZ!
Your Pistons don't look beyond redemption as you can get away with plenty of clearance on an air cooled engine.
Usually the biggest problem with 500 pistons is damage to the top ring groove. Have a good look at the side clearance between the top ring and the groove. In extreme cases the top ring will break and smash through the top of the piston into the head- your pistons look pretty good compared to many I have seen.
As the top ring groove wears it becomes out of square and will cause the new ring to break. If you have excessive clearance you can have the ring groove machined and a shim inserted below the ring to take up the clearance- have a close look once you have cleaned up the piston- if it has a small shim below the top ring make sure you leave it in place when you fit the new rings.
Also check the size of the pistons before you order new rings- if you clean off the crown of the pistons you should see any oversize markings- it is best to measure in any case.
Very few rings work in Fiat 500's most don't in even moderately worn bores- I had most success with Cofap brand rings- nothing else really seemed to work- in NZ the most commonly available ring was the Indianapolis 500 brand- do not use these under any circumstances! they have a 3 piece oil control ring rather than a cast ring and never bed in however you run them in- they just smoke constantly.
Also don't even think about fitting new rings without honing the barrels- it won't cost much but make sure you scrub the bore thoroughly with a stiff brush and warm soapy water afterwards or the new rings will bed in then wear out very quickly.
Finally make sure when you reassemble the engine that you assemble the pistons and rods with the expansion slots and rod numbers facing the camshaft - the piston is offset and I have seen plenty assembled back to front...
Good luck- it will be all worth it in the end!

 

[HamishNZ]

Engine was rebuilt, looked amazing and ran, I was pretty chuffed at my new red and black engine that sprung into life after all the hard work I had put in. A few things went wrong and this is lead me to think about purchasing a 595cc kit, am just in two minds as to what modifications if any to the head need to be made? I figure its cheaper to purchase kit then machine block to accommodate for bigger barrels than it is to purchase a new barrel (air cooling fins broke which caused issues) but if I need to make more adjustments to head then I think I will just buy 499cc cylinder and be done with that. As for progress on the body i have just finished cutting front panel, inner front panel sills and right hand front fender off and about to get the new panels welded in. Goodness it has been a bit of a bloody job, if only the welds were simply bolts and nuts haha. Ah well i have attached a couple of photo's to show progress. Enjoy, plus any technical tips or advice for body work would be much appreciated. Cheers, Hamish.

 

[Bambino]

A few things went wrong and this is lead me to think about purchasing a 595cc kit, am just in two minds as to what modifications if any to the head need to be made? I figure its cheaper to purchase kit then machine block to accommodate for bigger barrels than it is to purchase a new barrel (air cooling fins broke which caused issues) but if I need to make more adjustments to head then I think I will just buy 499cc cylinder and be done with that.

Hamish,
I've always been a believer in bigger bangs giving more power (within reason).
So to get more fuel/gas mixture into the combustion chamber you'll need a bigger carby matched to the inlet tract, bigger inlet valves held open for longer, bigger combustion chamber and to get the bigger bang, a tighter squeeze on the mixture and a reliable hot spark. You know where this is going.

Take the head to a trusted machine shop and get bigger inlet valves fitted. Standard on a 500 are 32mm and you will be able to go up to 34mm safely - that's a 13% increase in valve area.

Fit a copper head gasket to increase the compression ratio.

Get a sports camshaft.

Without doing anything else the engine will be more powerful.

Chris