Having already done the punto 75/cinq hybrid and a full 75 engine conversion I have decided to give a 1.4 8valve grande punto conversion a go!
I now have a full 1.4 8v and various other bits and pieces including a punto 75 head and cam.
Initially I was planning to use the 75 head and cam(modded) on the 1.4 block but am awaiting some posts in the punto section regarding the valve sizes on the gp.If they are bigger (and the manifolds fit without (much) modification, i will leave the gp head on and just do a bit of port matching.

I am also hoping that i can get away with using the 75 cam and not have any clearance issues as the gp has a higher comp ratio (11:1).
I will be using the standard sei (mpi) inlet manifold but will be using a bigger throttle body and at some point later,I will source a four branch exhaust manifold and fit a small cat further down the exhaust.
An issue did crop up while checking the auto data though.It tells me that the sei mpi fuel pressure is 1.2 bar (thought that was the spi?).I anticipate needing the 2.5bar I thought it ran at(will test it over the weekend though).
I like to keep things super simple so will only play around with the efi system if totally necesary.I plan to get it running in the car and check the injector duty cycle on a run to see if I need to increase the fuel pressure any which I hope will be enough to fuel it properly.I will consider slightly larger injectors if I really have to but dont intend messing with the ecu at all.
I dont know if anyone has attemted this conversion yet but I would love to see about 90bhp (I have seen standard gp bhp figures between 77 and 84) for the time being but am looking into forced induction in maybe a year or so when funds allow.
What does everyone think?....

This sounds like the sort of thing that interets me. I have my first ever Fiat Cinquecento project parked outside in the snow and am wondering about modding it for some extra hp.. I am slowly building up knowledge from folks like your self..all the best mate

richy0800 said:

This sounds like the sort of thing that interets me. I have my first ever Fiat Cinquecento project parked outside in the snow and am wondering about modding it for some extra hp.. I am slowly building up knowledge from folks like your self..all the best mate

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Thankyou
If you can get hold of a punto 75 engine/ecu/transponder/code box and engine wiring loom, check out my old posts for info on wiring it up cos its a pretty easy conversion for an almost 50% power increase.

be good to follow this one, there are a few 1.4 8v conversions on the go - but none finished yet.

is the stud pattern on the p75 and gp inlet manifolds different then?

arc said:

be good to follow this one, there are a few 1.4 8v conversions on the go - but none finished yet.

is the stud pattern on the p75 and gp inlet manifolds different then?

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It looks (by eye!) like the stud patterns for the manifolds are identical to the p75 (which I believe makes them the same as the mpi sei?!).I was going to whip off the head,have it skimmed to raise the comp ratio and mildly port it but the comp ratio on these is 11:1 already so not gonna bother with that now.The main (mechanical) issue i am pondering is the piston to valve clearance if I use the p75 cam(assuming it fits straight in).I havent done any measurements but assume it is the lift as well as duration that is greater than the p60 cam!

If there are a few people in the process of doing this,I might stop farting around and get it whacked in.Could have it done by the end of the weekend........

edit: Yes,just checked.The stud patterns ARE identical to the p75!!!!

I'm pretty sure the MPI Sei pump is 3 bar -- certainly the injectors are flowed at that pressure. The P75, I think, will be at lower pressure.

See if you can get hold of any data on the lift of the 1.4 v cam -- you may well find it's higher than the P75!

I'm not sure if the P75 ECU is amenable to a re-map. You'd expect it to need one and you may have issues mixing and matching injectors with the ECU. There's someone on the Punto section who managed to ditch the imob code on the P75 ECU, so there is hope. The 1242 16v ECU can certainly be re-mapped and might be more suitable. Or consider aftermarket.

Nice project.

fingers99 said:

I'm pretty sure the MPI Sei pump is 3 bar -- certainly the injectors are flowed at that pressure. The P75, I think, will be at lower pressure.

See if you can get hold of any data on the lift of the 1.4 v cam -- you may well find it's higher than the P75!

I'm not sure if the P75 ECU is amenable to a re-map. You'd expect it to need one and you may have issues mixing and matching injectors with the ECU. There's someone on the Punto section who managed to ditch the imob code on the P75 ECU, so there is hope. The 1242 16v ECU can certainly be re-mapped and might be more suitable. Or consider aftermarket.

Nice project.

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I always thought they were 2.5-3 bar!Damned AutoData!!
I do have a spare p75 ecu which may end up getting mapped(if pos) but I intend to see how it runs on the 1.1 ecu first.
I may very well end up just sticking the engine in as it is and replacing the cam later if it turns out that it might be beneficial.I could also leave the original throttle body on for now which will limit gas flow enough that I suspect the ecu and injectors will cope easily.
It might even end up being a better option for low and mid range torque.
Im all for experimenting so I might attack it this weekend if I get the urge!

Have a peek at this thread. I'm pretty sure than Team Lloyd used the stock Sei fuel pump (and Aaron likes buying fuel pumps ). 16v and 8v 1.4 have to use the same pressure.

Ok.Couldnt leave it alone but need to knock off now and have a shower!!

I roughly checked the height of the cam lobes with a vernier caliper and they appear to mirror the p75.Dont have time (or an angle gauge) to check duration but will look at that later.

Couple of issues.The rocker covers will not interchange and even if they did, I fear the cam sensor rotor wont.I have my fingers crossed that I can use the system from the gp and my sei will be happy with that!Gonna have to check the rotor on the sei to be sure.There is a pic of it from the gp below..

If its different I may have to go the route of swapping heads but really want to stay away from that if poss as I doubt the combustion chamber volumes will be the same (sods law!)

Also the coolant take off at the back of the head is blanked off (see below) but i am going to attack it with a tiny drill bit and see if it opens out into the water jacket.If it does i will send a big drill through it.I could just extend the hose but havent got a hose to suit and dont want to join it with copious amounts of jubilee clips like my p75 conversion!!!!

soozukisteve said:

Also the coolant take off at the back of the head is blanked off (see below) but i am going to attack it with a tiny drill bit and see if it opens out into the water jacket.If it does i will send a big drill through it.I could just extend the hose but havent got a hose to suit and dont want to join it with copious amounts of jubilee clips like my p75 conversion!!!!

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I'd stay away from it. Just use the 1.4 stat. I'm going that way on Imola Blue because I need the room for the induction system!

There's a lovely little turbo mani off a 500 abarth for sale in classifieds, Would this fit on ya 1.4???

davidlivings said:

There's a lovely little turbo mani off a 500 abarth for sale in classifieds, Would this fit on ya 1.4???

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Tempting....but I think they are 16v so doubt it would fit.I may think about forced induction next year,for now I just wanna see how easily and straightforward it is to slot in with the fewest additional mods.If I can get up early enough in the morning,I think Im gonna give it a go and see what happens.......Watch this space....

soozukisteve said:

Also the coolant take off at the back of the head is blanked off (see below) but i am going to attack it with a tiny drill bit and see if it opens out into the water jacket.If it does i will send a big drill through it.I could just extend the hose but havent got a hose to suit and dont want to join it with copious amounts of jubilee clips like my p75 conversion!!!!

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Now that is interesting, i'm mounting the 1.4 8v inlet mani onto my Head and it all matches up as it should, apart from the blanked off water inlet to the head. I would of thought that the 1.4 block wouldn't have it all judging by the mani...

Another thing I have noticed is the shape of the openings is different, sei ones are kinda teardrop shaped but the 1.4 one is more oval. Makes me wonder if i'll have some sort of flow issue.

Thanks

Todger182 said:

Another thing I have noticed is the shape of the openings is different, sei ones are kinda teardrop shaped but the 1.4 one is more oval. Makes me wonder if i'll have some sort of flow issue.

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Compare the HGs. There's a real sense in which they (rather than the passages in the heads) controls the flow.

Todger182 said:

Now that is interesting, i'm mounting the 1.4 8v inlet mani onto my Head and it all matches up as it should, apart from the blanked off water inlet to the head. I would of thought that the 1.4 block wouldn't have it all judging by the mani...

Another thing I have noticed is the shape of the openings is different, sei ones are kinda teardrop shaped but the 1.4 one is more oval. Makes me wonder if i'll have some sort of flow issue.

Thanks

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I have just matched up the p75 inlet manifold and it appears (again by eye) that they are identical!Thats worth noting for future reference as a sei/p75 hybrid inlet may work well.

If you are looking for every last horsepower,port matching is defo the way to go, but im conducting more of a feasibility study really.Can it be done on a budget with good results.I do intend in the future to look for all those wasted hp and possibly go forced induction but providing the sei port fits inside of the gp port,im gonna stick my neck out and say it wont cause too many problems.
On a carbed engine,in that situation you are likely to suffer from fuel drop out but the injectors on ours,although actually in the manifold,point towards the valve.The additional turbulence (despite the small drop in pressure) my actually assist in atomising the fuel and stop it sticking to the port walls.However,I expect that you will lose a small% of hp towards the top of the rev range.
Bare in mind that these engines dont produce very much hp per litre and as such,shouldnt be too suseptable(wont lose a lot of hp) to minor issues like that.Thats also why sensible mods can give good %hp increases.

I have had a peek at the sei cam sensor rotor and although its much bigger as it is actually part of the camshaft pulley, it is the same pattern.

Checked it over in the daylight and yes they are identical (guess we should compare things in the light hehe), it would appear the standard one is quite a restrictor as it did'nt match at all.

Now i've just got to solve my water inlet problem, thinking of cutting the blanked off bit and bolting the original in, just need to make sure that I don't cut through anything .

Thanks

Its alive!!!!!!!!!

Came across a few issues but going to go for a run now and see if i can finds some roads that still have traction!
Will update with pics 2mo.......

Well I didnt get in till about 2 this morn!!!

The first issue I came across was the seic engine mounting fouled the alternator belt and pulley.My mounting has seen better days so I decided to attack it with a grinder.5 mins later I had a couple of mills clearance!

The original manifold/cat/front exhaust required the sump to be dressed (read:Heat up and hit with a hammer!) a bit and I know have 8-10mm clearance.

I found a longer piece of hose for the back water pipe so didnt go near drilling the head!One of the small hose outlets on the gp thermostat needs blanking but for now I have just fitted a blanked off piece of hose.

Clearance of the manifold heat sheild and alternator are close in the car but Im going to play it by ear and address it if I need to.

The engine burst into life on the first touch of the key.
The exhaust note and throttle response has defo changed for the better!
However on road test, i came across a few issues.
At approx 1/3-1/2 throttle at any revs it appears to pull as hard as the 1.1!!
Any more throttle at almost any revs and it feels like its really holding back.I also periodically (when driving or idling) get the efi light coming on or flashing at which time I lose one of the fuel trim live readings on my diagnostic machine!When running normally(no efi light) the fuel trim readings fluctuate massively at idle or driving!
I get the p0300 code (apparently multiple engine misfire!) which I then clear and it stays off for a while.
I couldnt test it all properly as I was on my own while testing so will try to get to the bottom of it all next week when I can rope my boss into coming on a drive with me!
There is still a possibility I may have made a schoolboy error when connecting the loom back up or have a sensor problem.Wherever possibly I have used the sensors from my 1.1 so will have to look into that.

I still have all sorts to finish off.Sort the induction kit out,mount the coil packs properly,get a new engine mount,tidy the wiring etc....

Anyway,its in,it runs and it shows a lot of promise but I wont recommend this conversion yet until I have cleared up the running issue.

One splendid trick Emma's Dad (Jon) used was to use a strobe light to help see clearances between the alternator belt and the surroundings. Yours looks very, very close. Consider taking Mr.Noisy to the engine mount (there's plenty of meat on them).

Very fast work -- what ECU are you using? I can't believe it won't need a remap!

also if you space the engine mount, that'll help. As will using a shorter belt.

love the pace you work at

the car holding back, is it a fuel supply issue - or the TPS sensor going nuts? Try unplugging it