General Seicento 1.2 8v SPI Conversion

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General Seicento 1.2 8v SPI Conversion

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Oct 28, 2005
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Hi peeps,

Probably should re-introduce myself as I have been absent from the forum for some time now but am back to help a friend with a Seicento project, so Hi!

The headgasket in his Black Seicento Abarth 1999 1.1 SPI went the other day (Catastrophically may I add) so we have decided to put a 1.2 8v SPI punto engine in... We have read about the other conversions but as we have limited knowledge with ECU’s we have decided to keep it simple for our first try. We have both had Seicento/Cinquecento in the past and find the car good fun and a cheap way to learn a bit about engine swaps and tuning!

We have managed to pick up a punto mpi 1.2 8v very cheap and plan to use the bottom end for the build and retain the 1108’s head and all ancillaries. At the moment both engines have been fully stripped, the 1.2 that is going into the car to give it a full check and the 1.1 original engine has also been removed from the car. There are a few things I would like to ask before going any further.

Enginewise

After reading posts and the FAQ’s it appears I need to change the following parts to convert from the 1108 to the 1242 SPI;

1) You need to use the Cento crank position sensor. (After briefly looking is this to do with the length wires on the connector?)
2) Cento oil pressure switch complete with long hollow bolt and 90' elbow. (Fully understand this one as the punto one is not at 90 degrees and would hit the fan motor)
3) Lengthen manifold? (Hopefully we will be negating this by using the punto twin downpipe and moving flange to fit)

Over the next week we will be inspecting the 1242 bottom end and replacing the majority of the following to ensure we don’t have any problems later; head gasket, crank oil seals, camshaft oil seals, water pump, clutch, thermostat, cambelt, tensioner, and all gaskets.

The plan with the head is to get it skimmed down to near the max mark and run the thinner metal twin layer punto headgasket - 55189949. I ran this on my seicento setup and it ran fine for thousands of miles and this also raises the compression slightly more. (standard gasket 1.4mm MLS punto gasket 0.42mm). Slight intake side enlarging and porting and potentially remove the inlet valve stems that protrude into the port. On the exhaust side we plan just to remove any marks in the port and give it a polish, rebuild and reassemble.

Suspension and Brakes

Once we have got the car back on the road and fully up and running we plan to lower the car 40mm and completely upgrade to discs all round from another fiat model. This will have more research over the next few weeks as the priority at the moment is to get the car back on the road!

Engine Management

Regarding the ecu we were wondering what the best route to go would be. On the SPI versions I understand the chip requires a retune which is why people on the forum used a McCrich chip. Are McCritch chips still available or what other chips are out there to use? I have seen a Chip2Race chip advertised for the 1.1 cinquecento or seicento on ebay but will this mapping work on the 1.2 SPI engine, which has the power curve lower down, I plan on fitting? I guess also this will remove the immobiliser and requirement for chipped key?? Also we would probably want to source a spare ecu with a chip socket in to retain our original ecu in case of error or problem, I guess a cinquecento or seicento ecu will be ok for this?

Exterior and Interior

The exterior is going to be kept as standard as possible bar the SS exhaust tip and slight lowering and maybe some light tints on the rear... We are hoping to make a custom heater vent and get some gauges mounted in the heater vent so we can see how it is running whilst driving too!


Here is a list of some of the parts we have accumulated so far and some of the parts we are currently looking for engine wise;

Parts we have
- 1242 engine (came with all ancillaries so we now have some spares )
- GSR induction kit inc. 899 bob
- Custom centre section and Supersrpint backbox
- Standard Flywheel lightened and balanced - weighs 4.3Kg
- Punto 75 manifold and twin downpipe (I understand flange relocation is required to fit)

Parts we are currently sourcing
- 866 punto cam
- Uno 45 inlet manifold
- Larger 40mm Tricker TB or 38mm converted
- Spare ECU + ECU chip (potentially chip2race in a different ECu with socket to keep our own ECU for the moment but not sure which one we need, I guess McCritch no longer sells ecu chips??)

Currently I have no photos as they are all on my friends Iphone... What I will do is get some pictures up asap to show progress. If anyone can help with a few of the questions posted above that would be brilliant!

I hope you enjoy following the project.

Cheers,

Matt
 
That all sounds fine. The talk was that the late type metal gaskets needed the block skimmed, but if you've gotten away with it............. I still think a solid copper gasket would be better yet.

McCritch is no longer about, nor is Gazzaman, in fact, the only person I can think of doing chips is some guy out in Israel. Otherwise, it all seems to make sense. It is said that the maps are downloadeable from somewhere on the Internet if you have a chip burner.
 
I still think a solid copper gasket would be better yet.

I have looked into this, researched and contacted ferriday about these for 16v engines.

Result was it's pointless. (n)

Reason being is that the copper gaskets cannot give a 100% seal without some tweaking to the engine. The best solution was to machine o ring gaps into the block to accept copper o rings around the cylinders.

Obviously these fiat engines start to get a little tight for space between the cylinders (thank you fiat).

The guys at ferriday were helpful, his personal opinion was he would only do something like that in the most extreme of cases. MLS gaskets are a much more cost effective and proven method.

Thanks

X
 
Interesting, Todg.

I've seen no real evidence of head gasket issues with the later engines, that is, the ones fitted with the metal gaskets from the factory. Have you?

My concern was that the blocks on earlier engines are said not to have a surface finish suitable for hard metal gaskets (such as the later FIAT type). Thus, an annealed copper gasket might do the job better (and, if treated properly, could be re-used).

But if yer man has gotten away with it once, maybe he can again!

In any event, even the OE gasket early type should present no problems, at least, as regards seal.

Generally, the progression in gasket types goes something like:

composite gasket
metal gasket with silicone or polyurethane extrusions for water and oil channels
solid annealed copper gasket (using something like hylomar for water and oil channels)
solid annealed copper gasket, steel (pre-flattened) or hardenened copper O rings
Wills rings (which are sort of gas filled O rings, as used on Imp engines
surface ground head faces, no gasket, hylomar or nitrile O rings for water and oil passages
surface ground head faces (dry decked) oil and water passages by-pass the head surface

Of course, you can improve things a little by using better cylinder head bolts, better still by junking the bolts and using studs.

But this is way OTT for an NA street engine or a track day car.

IIRC, Rolls Royce used "surface ground head faces, no gasket, hylomar or nitrile O rings for water and oil passages" and Ducati used the same method on all of its air cooled engines.

The narrow fire ring on the FIRE engines rules out the use of Wills rings (as, I'd think, does the sheer expense and hastle) and might make the cutting of grooves for conventional steel or copper O rings damn difficult.

But wait! Assuming that the T Jet uses the same bore spacings as the other FIRE engines, then, surely, job done?

I'm not going to comment on Ferriday, except to say that they have my utmost respect (for what it's worth ;)): I didn't ask the questions, I didn't hear the answers!
 
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I have indeed had an issue with a possibly bad gasket. The BGA MLS gasket I used on my last build died miserably. May have been down to the lack of mapping the company did on the car (literally non). Killed alot of other things in the process mind.

I'm going to give the MLS type gasket another whirl but i'm not using a BGA one again.

As for your idea on upgrade headbolts/studs, again done some research and have been advised (by an ARP bolts specialist in my area) not to really bother. ARP will only supply a kit used on another car anyway. But will again be some overpriced stretch bolts that the standard items are already good enough for. I was impressed with the costs for the conversion however (if you enjoy your trousers round your ankles anyway).

Tjet's use standard stretch bolt setup from memory and a slightly thicker gasket than normal.

Thanks

X
 
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The ARPs are not stretch bolts (in the conventional sense -- of course, all bolts stretch) (I'm not even convinced that the stock 8v bolts are) -- they're high tensile ones with better control and checking than you're likely to find elsewhere. ARP (ARP in the States, that is, not some penny ante importer) will send you the details they need to roll bolts or studs to suit your application. While it's entirely true that the bolts will use the same thread and pitch as those for a Golf (talking 8v, here), they're hardly "for another car". It might be advantageous to actually have the 8v block machined to use the 10mm bolts the 16v engines use.

There is a genuine advantage to using studs instead of bolts. Ask any qualified engineer (rather than someone who has been around the car biz for a few years). But, essentially, they'll torque up more evenly. There may, depending on your engine, be disadvantages in that getting the head off is difficult or impossible. And, of course, studs will be harder to obtain than bolts, and 9mm harder than 10mm.

Another course of action is to use absolutely non stretch (in the conventional sense!) 12.9 grade cap head bolts. These will be black (because you can't plate them without embrittling them) and should have 12.9 stamped on them. The plated ones will, at best, be 8.8. They can be re-used pretty much indefinately (unless you find one with a manufacturing fault, in which case you're stuffed, but, then, people have bought bolts from their local motor factor and found they broke before they were even torqued up properly).

All the old guys, Gerard Sauer, Dave Walker, Guy Croft, have all used the 12.9 hex bolt trick at some time or another. If you're pulling a head off frequently for whatever reason, genuine stretch bolts soon become an expensive PITA.

Which brings me to the main reason ARP are so damn expensive -- as are aircraft quality, F1 quality, etc. fastners. The manufacturing processes tend to be slightly better, the materials tend to be slightly better, but above all, they are checked for quality and integrity. It costs. Whether the cost is worth it depends pretty much on how much the rest of the engine cost. I mean, you'd be barking mad to use Carillo rods in a 54bhp street Cinq, but you'd be be just as crazy to use standard big end bolts in a full race 1108 engine that had cost £5000 to build.

Det will certainly kill a head gasket quickly. Go thump them. Hard.
 
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I take it Gaz has actually up and left now, not seen him post for a while.

Nah he still hangs out, just a difference in timezone. He's still following the Monster thread (seen him lurking a few times :D), and so he should because once it's finished he will of course played a fairly decent part in it by supplying the engine. (y)

Can't see him sending you any chips from Canada though....

I don't know what the deal is here, who actually owns the rights to the map on the McK/Gazzaman chip? Did Gaz by the rights from McK etc... (I'm assuming so).

Someone really needs to ask Gaz then I can't see any reason why they can't be read and duplicated on a universal programmer. Programmers cost peanuts these days, I have several types and I'm certain Woj has a programmer too. He surely knows the chip details since that's how he realised his project.

So it all comes down to who owns the map as duplicating chips is as easy as cooking them.
 
The project is moving along nicely and we have acquired some more parts;

Parts we have
- 1242 engine (BOTTOM END NOT USABLE :( )
- GSR induction kit inc. 899 bob
- Custom centre section and Supersrpint backbox
- Standard Flywheel lightened and balanced - weighs 4.3Kg
- Punto 75 manifold and twin downpipe (I understand flange relocation is required to fit)
- 866 punto cam (member on forum)
- Punto 75 38mm TB to adapt to fit (scrappie for cheap!)
- ECU chip from Chip2Race ebay (after research it seems the 99 sei ecu will have a non soldered chip so hopefully thats all go)

Parts we are currently sourcing
- Uno 45 inlet manifold
- 1242 Bottom end that is actually in good condition!

Well after more work today we have come to a bit of a sticking point... The bottom end of the 1242 engine we picked up is acutally knackered... 3 of the 4 pistons have the top ring stuck in, little end bearing seized and 3 of the 4 bores are in a bad way... Only 1 piston and bore out of the 4 would be useable... Crank looks ok but looking at the price of parts it is going to be far cheaper to pick up a new bottom end that is in good condition and visible on purchase... We bought the engine whole and even removed the plugs to check it turned over nicely which it did... The seller assured us it ran but there is no way that engine ran, if it did it didnt run well thats for sure... I would suspect head gasket failure caused it and then it being run with no water which has then melted the top ring in place :(

So we are now on the look out for a later/newer mpi 1242 bottom end with less mileage and potentially one with garantee before we can progress! If anyone knows which ones are the best to look out for or has one lying around that they know is in good condition pm me!

Cheers, Matt
 
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