Pre-Project: You crazy mo'fo..

[ginge191]

you got it grant, but no, single turbocharged is the plan on this, "MAY" keep the standard j4rs head, then build a 1.8 bottom, forged pistons and rods, buy a decent turbo and get my engingeer friend to build a manifold to extend round to the battery box.

As i was saying, the biggest issue im finding is the ECU's

And ED, read ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ , basically what i'm attempting. And i dont 'really' want to juts get a bolt on jobby, thats too easy, i'm in no rush to get this done. it's a learning curve for me and if the end results are amazing, then bonus.

[Ruan]

Remember, an XU7JP4 is essentially a stroked down Mi16... Uses the same liners for certain.

Mi16 pistons should fit, if you get low comp 1.9 Mi16 pistons, they should fit fine - at least around the bore, you will have to get custom rods made up, but it's not too much of an issue...

Essentially your conrods will need to be 1.9 Mi16 on the little end (if you use low comp 1.9 Mi16 pistons) and then XU7JP4 on the other end, but the overall length of an XU7JP4 (that's only if the Mi16 gudgeon pin width is different, but I doubt it - if it's the same, just get them to copy an XU7JP4 rod).

You'll need to do some measurements of piston crown height from gudgeon pin centre on Mi16 vs an XU7JP4 - that'll tell you how long the rods need to be, since if the crown height of a 1.9 Mi16 is say lower, combined with the XU7JP4 rods, you might find that the piston top sits too low in the bore, meaning you've got shit all compression...

I would personally get the conrods modified to accept off the shelf forged pistons - that's much easier than creating custom pistons - in a boosted petrol that was once NA you can take pistons as an expendable item if you're pushing the engine...

But then if it were me personally doing this build... I'd probably just stick a set of forged pistons on stock rods as long as the gudgeon pin width is the same for an Mi16.

[Dum-Dum]

I know im a little late to this thread mate but Megasquirt is the way forward. It can be mapped by EVERYONE and its tuning software is simple enough to make it easy to map yourself to a reasonable standard. If you dont believe me the software is a free download so have a play.

Megasquirt can be bought brand new for about £300 but you can build one yourself if your good with electrics for about half that.




A reputable UK company to get a ready built microsquirt kit from
http://trigger-wheels.com/store/contents/en-uk/d31.html
Less than £290 inc VAT for the ECU and a basic loom

[Ruan]

Yes you can do it yourself, but not everyone knows how to map it - the UK hasn't got the biggest market for Megasquirt unlike the US in all honesty...

People (read: tuners) slag off Megasquirt because in fairness, it does have relatively crappy injector control - you have to reduce the fuel pressure SO much to get the injection length fine enough for the ECU to control, the fuel vapour condensates, drips and therefore runs like a sack of shit, it's simply not fast enough or advanced enough to control 800cc injectors at idle on a 1.6 litre engine lol... Hence they lump all over the place, stall etc - that's just a characteristic of big injectors and big valve overlaps on an ECU that simply isn't fast enough to control it correctly.

A lot of places will tell you to get Emerald, MoTeC, Omex, DTA or similar, they have much superior injector control, IAC control etc...

I like Megasquirt a lot, but unless you're prepared to find somewhere with a dyno, do a MASSIVE amount of research and do it yourself, you're often better off using a system that people know about - Dave Walker is one of the UKs best people for mapping and he owns/runs Emerald - Caterham even uses Emerald from the factory, it's THAT good...

[silverzx]

Sounds a lot like the piggyback ECU's I used to have for my S13 CA18DET. Everyone swore by the same brand, just can't remember it's name. >_<

[ginge191]

But then if it were me personally doing this build... I'd probably just stick a set of forged pistons on stock rods as long as the gudgeon pin width is the same for an Mi16.

this is what i was considering - seeing that if anything was to go, the rods would part before anything else and i could easily get through a few sets - saying this, considering the rods would stay in the block :think:

Then again, finding 1.8 forged pistons are proving a test, and may need to be custom jobbies anywho.

I'm intending to keep the 1.8 bottom, and using forged pistons, and if £££ allows, forged rods, with the standard j4r head (perhaps valve springs and cams, again, £££ dependent). It seems the potential Mi16 engine is out the question (depsite it being the 1.9 lump) whatcha think? :think:

Ideally i wouldn't like to spend a FORTUNE on this, as it is a learning curve and a 'project', not a business for me.
Getting a car with a decent spec, for ~£3k is the challenge.

[Ruan]

You don't need "custom" 1.8 pistons - like I said, do some research, I think you'll probably find that the 1.9 Mi16 pistons are actually pretty much the same as the 1.8 pistons, as said before, the 1.8 is a *stroked* down Mi16...

You don't need to touch the cylinder head - as you've probably seen they'll do 400hp with the S/C kit, don't waste your money there, they flow INCREDIBLY well as standard...

[ginge191]

Cheers ruan the head info, big help. Saves me looking into valve springs, pressures, cams etc.

I'll look into the mi16 pistons and linking bolts; once sobered up and got some spare time. Seems as though this project is a go ahead!

[ginge191]

Just a heads up, for anyone that may know - or know where to find the info - both 1.8 and Mi-16 engines have a 83mm bore which is fine for the piston, but the stroke's are different, obviously the 1.8 is shorter, at 81.4mm, compared to the Mi stroke of 88mm.

Anyone know where to find out gudgeon pin sizes? i need to know the 1.8 vs the Mi-16 size..

[samass]

You could find out the mi 16 ones by swing those that make the forged ones, presuming there are some people that do? Or people selling replacements. The 1.8 ones can be measured when you get hold of a set, or maybe speak nicely to pug?

[ginge191]

mi16 forged pistons here (wossner) http://www.performanceenginecomponents. ... asp?id=150 for a pretty decent price.

If the gudgeo pins match, i'll get hold of forged 1.8 rods (OR i think i saw Dave a while back reinforcing his rods :think: , i was flicking through his pictures and didnt read it )

[samass]

irrc dave never used those rods, for one reason or another, cant remember what tho lol!

send them an email asking them about the pin sizes and that, they might well have info on other engines aswell.

[4WayDiablo]

Dave did use them rods iirc
They were welded but the weld came off and collected in his sump lol iirc

[Ruan]

Check servicebox.

Once you have measurements, you can stick it into a calculator and work out your compression ratio.

[ginge191]

so with the mi16 engine, stroke of 88mm, the compression ratio is 10.4:1, with a shorter stroke of 81.4mm, it would increase the comp ratio. Math isn't my strong point, anyone got a brain :oops:

http://chainganger.co.uk/Page2/Page2.html

:think:

I'll get on that later, i gotta go flower shopping :|

[Ruan]

88mm stroke 10.4;1 compression

Drop the stroke to 81.4mm - if you kept the rods the same length and the crank position the same, you'd end up with the piston sitting lower in the bore at TDC by half of the difference between the strokes - 3.3mm... It'd also sit higher in the bore at BDC, again by half of the stroke difference - 3.3mm.

Higher at the bottom by 3.3mm and lower at the top by 3.3mm = your 6.6mm difference in stroke.

Now, whether peugeot decided to extend the conrods or slap feckloads on the piston crowns in the 1.8 application - I don't know...

[ginge191]

This is what PEC have repied with

The Wossner piston has a 22mm small end. We have a few different combinations of pistons and rods in stock that might be of help to you, can you let me know the stroke and deck height you are planning on using?

The stroke of the JP4 engine is 81.4mm, and the deck height?

working out - http://www.faliconcranks.com/pdf/rodlen ... height.pdf - but i havn't got any of these to hand?
Anyone got any ideas? :think:

[4WayDiablo]

If its of any help the Bosch fuel pump mentioned "044 inline" I can get hold of for 124 quid :-)

[ginge191]

@RUAN: if i understand what you're saying; is if i use the Mi16 block with the 1.8 rods, to create a shorter stroke and lowing compression? This would be ideal, and would mean i could keep the head from the Mi16 and just replace the rods and pistons.

But i would question where the crank sits and whether the 1.8 rods would be compatable with the mi16 block?

This would then mean then not needing a XUJ4RS lump at all?

EDIT: cancel this ^^^^ ... if i was to use a XU J4RS engine, and used 1.8 rods, i'd be similarly lowering the compression which would be ideal? again, would the rods be interchangeable.

[Ruan]

The crank is what determines the stroke...

Conrod length is to essentially "correct" the adjustment of crank throw and put the piston in the right place.

Which is why I say use the 1.8 crank - the 1.8 crank is the part you want to keep - you need to find out what parts are adjusted between the Mi16 and 1.8.

[ginge191]

So ideally, i just want to get hold of a GTI lump and a 1.8 lump and start taking it apart and seeing what fits where? putting it simply?

[Ruan]

Mi16 lump - Mi16 and GTi6 are totally different.

You don't want to use a GTi6 crank IMHO.

Stick to the 1.9 Mi16

[ginge191]

...but the whole idea was to be using a 1.8 bottom end lump for lower compression.

The mi16 engine only come into question when i was looking for forged parts, and the Mi-16 forged parts seem to fit the 1.8 lump (on paper at least), and then use a GTI head :think:

I don't think i could warrant spending £175 on an engine (mi16) which is going to be little/no use to my build..?

:think: