Rebuilding/upgrading A 1.9 8v

[cRaig 273 1 Cars]

Hey there.

Just a thread to start assessing my options really. As the progress is being pretty quick on my 1.9 shell, and it should be looking pretty mint this time round (it wasnt bad last time lol) Im quite tempted to keep the Mi16 engine I have for another shell, and get the 8v rebuilt over this winter to put back in it, as I do like the character of the 8v.

 

Anyway, Ive been doing some trawling through the search results, and I cant find many threads discussing upgrades for the 8v engine. (im sure they are there maybe Im being blind!)

 

Anyway, Id just like suggestions as to what its worth spending money on rebuilding/upgrading an 8v engine. Budget is fairly flexible, but Id like it to be running the standard inlet manfold (to look standard! ) So that rules out carbs etc lol. Drivability around town is still pretty important to me.

 

As for power figures, im not after huuge increases, but something a bit nearer to the 130bhp we were promised from new would be nice lol.

 

Apologies that this thread is so vague, but I dont know a huge amount about engines, and as they say, a little bit of knowledge is a dangerous thing

 

Ideally if someone had done something similar and could drop a spec list in here for inspiration that would be awesome

 

 

P.s.. people may remember the thread where I admitted my engine is pretty broken atm (made 60bhp) on some rollers.. But we never did get to the bottom of it, but I doubt its mechanical, as the head had been serviced earler that year. Worth investigating, and Id be happier once the engine had been apart, rebuild by someone who knows what they are doing, and all the sensors can be tested and replaced as necessary, injectors cleaned, afm serviced etc..

Craig

Edited October 31, 2009 by cRaig

[welshpug 1,661]

1.6 pistons, mild lumpy stick, Motronic management

 

 

that'll get you easily over the 130 bhp mark, mine is at that with just the motronic management.

 

 

 

unsure at what level the head needs attention really, I don't think its like the Mi16 where they can go over 200 bhp with the right cams and bottom end.

Edited October 31, 2009 by welshpug

[DrSarty 90 1 Cars]

Firstly I'd say that you know the engine's pretty good as it is, although it will be old and a little tired, down on standard power and will benefit from a refresh.

 

Even just taking it apart and giving it a good clean:

 

a refurbed AFM, new dizzy (the advance mechanism gets tired), rotor arm, HT leads, cleaning through all breathers, upgrading the earth leads (& cleaning the earth points), ASNU cleaning the injectors, new filters x 3 and re-seating (triple-cuttting) the valves in with new valve stem oil seals...

 

will give you a much happier lively engine. You would/should check the bottom end bearings etc as a matter of course.

 

If you wanted a power increase over standard, then the best place to achieve it is in the head and perhaps giving the engine a shorter and cooler air intake system.

 

The new valve seats will help, and you could look at a new cam, some of which need/benefit from a head skim (the one below needs about 0.712mm) and re-shimming of the valves (getting the clearances right). In fact the latter will help even on the standard engine.

 

I can't vouch for any cams in particular, but my 1.9 GTI has this Piper Cam fitted, and it apparently pulls very well indeed. That said, 1.9s do anyway when running properly. Piper (perhaps over-enthusiastically) claim a 20bhp gain from this cam when correctly fitted, i.e with the skim etc.

 

That's just a basic approach rather than one specifically on tuning the 1.9 8v. Some with experience may encourage you to fit a different cam and even fit bigger valves.

 

Hope that helps though.

[cRaig 273 1 Cars]

Thanks for the info so far. DrS: A nice logical post to give me an idea of what to work through, thanks Its well worth remembering that theres no point chasing more power until things like the dizzy and afm are 100%.

 

So the 1.6 pistons are different in stroke? That increases the compression? Then can get away with a lumpier cam?

Very tempted by the idea of motronic management, something a bit smoother I imagine..

[Tom Fenton 1,542]

If its only making 60bhp then it sounds pretty damn tired to me, so at a minimum I'd start with new rings, bearings, honed liners etc. Any other go faster bits are wasted money if you start with a shagged base.

[cRaig 273 1 Cars]

Yeah, Im thinking full rebuild from a base point, whatever needs doing to get it back "as good as new" My question was really is there anything worth replacing in addition (sensible "better than new improvements) while everything else is being done? Sorry if that was a bit muddled, engines arent my strong point..

Edited October 31, 2009 by cRaig

[cRaig 273 1 Cars]

Been doing some research in old threads, and Anthony's 8v seems good: XU10 2.0 head on the GTi block. Seems to be a fairly smart solution..

 

Too many options lol.

 

Ramblings on the back of a fag packet kind..

 

New piston rings

New/rehoned liners

New main & big end bearings

Vernier Pulley

New oil pump with uprated (Mi16) spring

Rebalanced bottom end

Lightened (or 1.6) Flywheel

XU10 2.0 head ported to suit XU9 block, with larger valves, tripple cut valve seats etc

Standard or slightly lumpier cam?

 

Motronic management

 

Criticism is more than welcome I want to get this engine right, and that'll only happen if you guys help, I have no idea what Im doing!

Edited October 31, 2009 by cRaig

[DrSarty 90 1 Cars]

Just to clarify a couple of points.

 

Craig edited his post (the bit at the bottom), because when I replied I didn't know about the woeful 60bhp affair. Anyway, when I said "the engine's good as it is", I meant a standard 1.9GTI engine is, not Craig's; and certainly not based on the bit he added.

 

Phew!

 

As for 1.6 pistons. The dish/face of them is different. You don't change stroke by pistons but by crank and/or rods. I'm sure that's what you meant.

 

Your list looks good to me. Certainly may be worth experimenting (doing calcs) of using the 1.6 pistons to go with that set up, to ensure CR doesn't sky rocket and you have sufficient valve clearance.

 

Again this is just general advice.

Edited October 31, 2009 by DrSarty

[cRaig 273 1 Cars]

Like I said, regarding the 60bhp, we are fairly sure its management/tuning/timing rather than the engine being shagged- the head had been refurbed, and it didnt smoke etc. Granted thats no guarantee, revved cleanly etc. Could have been fueling, filters etc. Didnt get around to sorting it, and now the bodywork is a bit more of an issue.

But now is a good time to sort the engine, and it has done 116,000 miles, so a bit of a refresh to ensure reliability for the next 100,000 miles would be nice

 

Thanks again DrS. Its nice just to get ideas from a few different people, and to make sure I dont miss something obvious.

[DamirGTI 342]

- new piston rings and honed liners

- new bearings (main + big ends)

- 1.9 DFZ pistons (for boosting up the CR)

- head porting job/cleanup (could at least re-do the short side radius ..)

- 3angle valve seats (on the head and the valves as well)

- inlet manifold and TB rework

- 1.6 flywheel

- race cam (if you wish ..)

 

.. i've done this (bar the race cam) and i like it it's cheap and very effective mod. , just need to decide on which management you'll set up and run the engine either fully mappable or std. one with a little bit of tweaking .. mappable would be better for sure at least ignition only ..

 

If done and adjusted properly it'll push over 130bhp mark ..

 

Damir

[cRaig 273 1 Cars]

Thanks Damir That seems like a fairly logical, and relatively affordable! approach to things

[welshpug 1,661]

I think you need to start off by stripping your old engine down and seeing what was up with it, might have had a blocked exhaust, worn rings/liners, worn out camshaft, or just really badly setup management.

 

Worth noting, I think the DFZ pistons Damir mentions are the same as a 1.6 piston, definitely like Sarty said the precise C/R figure needs to be calculated before you steam ahead as you may well end up with too high a compression ratio for street fuel.

 

Also, if you're looking to use different management I would fit an XU7 flywheel, its the same as used by the Motronic 1.9, half a kilo lighter than the Jetronic 1.9 one.

[Miles 331 1 Cars]

Fine to use 1.6 pistons as allot of people have done this, I;ve got flat top's in the Gentry and around 12.5:1.

No need to replace the oil pump unless very worn, Pattern one's again are worse then 200k old std pump's

[DamirGTI 342]

1.9 DFZ pistons are the same as 1.6 ones , conrod length is different in between the two assemblies .. so if decided to go this route id suggest sourcing a set of 1.9 DFZ pistons as they're plug and play option , no need for conrod pressing out/in as in the case of 1.6 item

 

With regards to CR and fuel octane , CR will end up around 11.1 mark so 98 RON is a must just as modified ignition advance curve (in the case of using dizzy system) , or mappable ignition (preferably but not necessary) .. from my experience reliability is not an issue with this kinda modified engine , if adjusted properly it'll last for good years just as std 8v ..

 

Damir

[welshpug 1,661]

trouble is in the UK they are not easy to find Damir whereas the 1.6 is plentiful!

[DamirGTI 342]

.. really ? well the 205 CTi (cabrio) cars had this 1.9 DFZ engine , some odd 309 GT's etc. cos it isn't popular engine because of low CR i thought that it'll be common on a scrappy

 

Anyway some other 1.9 engines also had the same pistons type as this DFZ one , i need to check the engine codes .. but something like DDZ or D2D from 405 rings a bell (if those aren't flat tops , i'm not sure ..)

 

Damir

[welshpug 1,661]

cars like these are virtually unheard of now, the price of scrap last year made it more worthwhile to crush whole cars rather than strip for parts.

[omega 82]

.. really ? well the 205 CTi (cabrio) cars had this 1.9 DFZ engine , some odd 309 GT's etc. cos it isn't popular engine because of low CR i thought that it'll be common on a scrappy

 

Anyway some other 1.9 engines also had the same pistons type as this DFZ one , i need to check the engine codes .. but something like DDZ or D2D from 405 rings a bell (if those aren't flat tops , i'm not sure ..)

 

Damir

 

 

think this is the engine thats fitted to the automatic cars

[cRaig 273 1 Cars]

So would it be overkill to use 1.6 pistons with the XU10 Head? Can someone tell me what the compression ratio would be, and would it be worth doing etc?

 

Thanks,

 

Craig

[DrSarty 90 1 Cars]

So would it be overkill to use 1.6 pistons with the XU10 Head? Can someone tell me what the compression ratio would be, and would it be worth doing etc?

 

I wouldn't say it would be overkill, because the XU10 head will have an 86mm chamber, which you will be sitting over an 83mm bore.

 

Wardy18 has just done this and spent a lot of time working out dish sizes and combustion chamber volumes to end up with CRs. You should PM him.

 

I think this would be a good route (with the different pistons), and as stated by more knowledgable people, you can use either 1.6 pistons or the DFZ low comp pistons from the 1.9, where the latter wouldn't require any faffing with con rods that the 1.6 pistons would.

 

Now you could do us all a favour and find out which cars (available in the UK) had the 1.9 DFZ engine......

 

 

Here are 2 I know anyway:

405 1.9i XU9J1 (DFZ) 1988 - 1993 Mono - Jetronic 105 @ 6000

205 1.9 GTi XU9J1 (DFZ) 1987 - 1994 Bosch LU2 Jetronic 102 @ 6000 - CTI and also the automatic, which is the Gentry? (VIN Code 20CDF2)

Edited November 1, 2009 by DrSarty

[Miles 331 1 Cars]

All very well with the XU 10 head which as many know I don;t like as it's hit and miss on what H/G to use, I;ve seen both used. Also your better off sticking larger inlet valves in the XU9 head then you get a 100% right head and not a make do head

[martin81 1]

All very well with the XU 10 head which as many know I don;t like as it's hit and miss on what H/G to use, I;ve seen both used. Also your better off sticking larger inlet valves in the XU9 head then you get a 100% right head and not a make do head

 

I've just put a XU10 head on my XU9 CTI block... minimum skim, valves fixed and reshimmed to 0,3-0,35 on exhaust and 0,2-0,25 on inlet, and I kept the standard CTI camshaft as it looked just fine... I runs perfectly on 95 petrol..

Im on to get it benched for new power output...

[bobdylan_55 1]

con rod length doesnt affect stroke

[harryskid 193]

Tuning 205 8 valves

Take a look on www.peugeot-205.co.uk

Also the mi might be a cheaper option

Harryskid.