1608cc rebuild

[fiatfactory]

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[djape1977]

all input on the subject is welcome, that's why i opened this topic.
this is not my car but i'm working on it for a customer and it's a ground up restoration. since 124 spiders are extremely rare here, getting original parts is very expensive since everything needs to be shipped from abroad. customer decided to go for 1608 because original 1438cc was long gone and at some point swapped with 2 litre from 132 which was destroyed after a timing belt swap gone bad.
owner of the car decided that he wants 1608 and that was it. if it was my car, and i was unable to get the engine that was in the car originally, i'd go for any of the later motors with 84mm pistons. at least i can get the parts within a 10mile radius for those.

as i said, this is what we could find locally. i'm aware of some of the diferences between diferent 1608 engines but i'm still learning and will be learning unill the day i die.
this particular engine came out of 124bc but who's to say it hasn't been swapped at some point of it's 40+ years?
interestingly enough, it has a crankshaft with larger counterweights.
by the way, is there any benefit of using bronze valve guides apart from the fact they wear out faster?

[djape1977]

what's your 2 cents on a re-ground crankshaft i now have? first undersize all round. doesn't need re-grinding but bearings i took off have some damage and i won't be putting them back in.

[fiatfactory]

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[djape1977]

ok. will do so.

valve guides - i couldn't find bronze ones anyway so i'll use what i could cource. knowing what's locally available, i don't believe i would manage to find a kind of bronze needed to make valve guides.

crank bearings - i have sourced locally a set of 1st undersize bearings for 1438cc engine but as you know, conrod bearings don't fit 1608cc. i'm looking all over for these but no joy. any idea if there was any other engine that used the same size? if not, i'll have to buy on fleebay and wait for couple weeks untill they arrive

[fiatfactory]

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[fiatfactory]

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[djape1977]

so it happens that what i have is a crankshaft from 125bc apparently, although it was removed from 125a block. was there perhaps more variations than you're aware of?
larger size, one that's unique to 1608cc, definately not the same as for 128 engines, they are very common here and i'd have no problem finding it if that was what i needed.
anyways, i have found locally a set of 0.20 bearings for 1608 so problem solved. the crank has already been re-ground to 2nd undersize for conrod bearings and pistons are connected to conrods, so build goes on.

thanks for your offer to help, i'll probably need it again sooner rather than later.

by the way, if you happen to need 14mm valve guides, they're readily available over here and very cheap. same goes for 80mm and oversize piston rings.

[fiatfactory]

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[djape1977]

just checked, definately all 1608 engines i have use larger crank bearings than 128 engines.

[fiatfactory]

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[djape1977]

that makes sense.
around here, first time 1608 engines appeared in any significant numbers was in 1969 in fiat 125 (90hp) and later in 125 special (100hp). before 1969 fiat twincams were non existant here so it's highly unlikely that i'll ever come across an older one. 124 coupes and spiders were rare as hen's teeth, in all likelyhood no more than 500 units in a country of 20+ million people, while there was 50.000+ officialy imported 125's and probably at least that much grey imports to add.
any engines that i come across, even in a coupe or spider, have most likely been replaced by unit that came out of crashed or rotten 125 at some point in past 40+ years.
this particular 124 spider had 1438cc unit to begin with and at some point, likely in latte 80's, it was replaced with 2 litre from 132.

and say hy to your dad, it's nice to know that old craftsmen are stil around

[djape1977]

any idea why is there "linea 5" cast on the side of the block?

[BEEK]

no idea but every 1608 i have seen has that cast on the side of the block . maybe a production line? who knows

[djape1977]

while head is at the machine shop, some more work work got done

before



after




before



after





more misc pieces









original cams from 1608 were damaged, as well as one cam housing, so i went for cams and housing from bog standard 132 2 litre


by the way, anyone got idea what colour codes on the cams mean? i've got ones with red strip, yellow, orange...

dipstick cleaned and new rubber installed.


oil pan straightened, repainted and cleaned


new water pump


intake



and lower part of the engine pretty much done