xu5m engine rebuild

[apitiser]

Ok, so I had a visit with the machine shop guy today. Got some good and bad news from him.

Good news. He thinks the bottom end and crank look like they are mint condition. Crank is perfectly in spec with no wear.

Bad news. He said the head looks like scrap with the pitting and that it looked like the wear in the head came from being used with a blown head gasket and water with no coolant used. I added a picture with the section he thinks looked bad.

I talked about getting up to 2mm taken off the head and he said that's stupid. Whoever said to take that much off the head is full of sh*t and no one would take more than .5mm off.
Also 11.1 CR wouldn't work with the 94 gas here.

So I'm not sure what to do now. Look for another shop to do the work? This guy came recommended from a few of my friends who have had their mini's and V8s rebuilt by this shop but it conflicts with the information I want to follow from the Peugeot people in this group. I was told this guy would be quite condescending and he lived up to it.

 

[PeterT]

He's full of sh*t. It's common to take up to 2mm off safely. Google 205 Forum. If he's never machined a 205 head how would he even know?

I've taken 2mm off AND used a 0.7mm copper gasket.

If you're in any doubt, just take 1.5mm and leave 0.5mm for another rebuild.

Tell the dipstick to ring me.

 

[apitiser]

He's full of sh*t. It's common to take up to 2mm off safely. Google 205 Forum. If he's never machined a 205 head how would he even know?

I've taken 2mm off AND used a 0.7mm copper gasket.

If you're in any doubt, just take 1.5mm and leave 0.5mm for another rebuild.

Tell the dipstick to ring me.

I would love if you could call him and correct him haha. It was frustrating listening to him

 

[djvu205]

Dropped my crank and head off to get measured and checked out before I buy parts.

Before I took the head to the shop the machinist said to put some solvent into the head to see if any of the valves leak. two of them did. This is the first peugeot engine he has worked on so what things do I need to make sure he does?

How do I know if the head has been skimmed before? I want a higher CR but I'm not sure if it has been skimmed in the past. Is there a measurement on how thick the head should be?

Also I have some bike throttles for the car. I haven't decided which ecu to go with so what would people here recommend? Megasquirt seems like a good option.

does the Si have the same fuel pump as the Gti or is it smaller? Wondering if that needs upgraded

If your running carbs you can use si management. Just unplug fuel related stuff. The magneti ecu only needs map sensor and crank sensor for ignition and if bike carbs have tps make it send same signal as 205 tps. Without tps mine still ran ok. I was running zx6r carbs on a xu9 d6b motor with stock si management. It went very well.

 

[cam85]

My mate owned that car/engine before Graham/Cal etc. was a good one. Head looks salvageable and agree with Pete that your engine guy is missing the mark. Theres plenty of meat there but good to check and measure as it may have been lightly skimmed before.
Mi16 box is the way to go. If you have to import one get a xsara vtx box if you can. Essentially same ratios 1-4 with a slightly longer 5th. But negligible so if an Mi one comes up grab it.
Also, 94 fuel there should be 98/99 ron I believe.

 

[GRAHAM WALLIS]

In my case the calculations for .2mm off the head, 9.8 GTi pistons and .9 mm head gasket worked out at bit over 10.5 to 1 . I would say don't bother with the GTi pistons unless you can get them easily. Of course a large amount from the head will then retard the timing and you will need an adjustable pully. Where would you get the GTi pistons from Api?

 

[GRAHAM WALLIS]

The attached article details what PTS did to make a quicker 1.6 GTi. Based on the 105 Hp early model. Bigger valves would be just the ones fitted to the DKZ or Si heads I would think. 125 Hp at 6900. Later 1.6s were 115 Hp.

 

[apitiser]

In my case the calculations for .2mm off the head, 9.8 GTi pistons and .9 mm head gasket worked out at bit over 10.5 to 1 . I would say don't bother with the GTi pistons unless you can get them easily. Of course a large amount from the head will then retard the timing and you will need an adjustable pully. Where would you get the GTi pistons from Api?

I haven't got the pistons yet but going to try and find some in the uk and get them shipped with my pug1off order. I'm not sure how to work out what amount I need to skim and what head gasket thickness to go for to get 10.5-11:1 ratio with the stock 8.9:1 pistons.

If your running carbs you can use si management. Just unplug fuel related stuff. The magneti ecu only needs map sensor and crank sensor for ignition and if bike carbs have tps make it send same signal as 205 tps. Without tps mine still ran ok. I was running zx6r carbs on a xu9 d6b motor with stock si management. It went very well.

thanks for that info. I was planning on swapping out the entire loom and going aftermarket but this would be a great cheaper option

 

[GRAHAM WALLIS]

I haven't got the pistons yet but going to try and find some in the uk and get them shipped with my pug1off order. I'm not sure how to work out what amount I need to skim and what head gasket thickness to go for to get 10.5-11:1 ratio with the stock 8.9:1 pistons.



thanks for that info. I was planning on swapping out the entire loom and going aftermarket but this would be a great cheaper option

Don't remove the original loom, things other than Engine Management stuff go through it, just tape up the unused wires.

 

[PeterT]

You don’t need to swap the pistons. Just skim the head.

 

[GRAHAM WALLIS]

Rings are different for the 1.6 GTi and Si pistons.

 

[apitiser]

you're all gonna save me so much money and time. thank you.

You don’t need to swap the pistons. Just skim the head.

Will I need to take 1.5mm+ off the head to end up with 10.5-11:1 CR? and will I need a thinner head gasket?

Rings are different for the 1.6 GTi and Si pistons.

I hadn't considered the rings being different between those two pistons. will make sure to mention that when ordering my stuff

 

[GRAHAM WALLIS]

One or two of the Si rings are thicker. GTi same as 1.9. Thinner headgasket will give more squish but not essential just to get the higher compression since you have the option of taking off 2 mm.

 

[PeterT]

Post a picture of the chamber with some measurement ie width x length. I don’t have one here to measure.

 

[PeterT]

A few rough calcs suggests 1mm skim and a 0.7mm Cometic gasket will give you approx. 10.4:1.

 

[apitiser]

Been busy with work and also had an autox event which I took the 205 along. I'll get a few pictures next time I head to my garage

 

[apitiser]

bit of an update.

I have found an engine builder to do the work! His name is Gil and he has been really insightful and showed me around his work shop while explaining everything that he does.


The liners out of the block now and it doesn't look like there is any corrosion on initial visual inspection. I have added some picture of the block to my album.

https://photos.app.goo.gl/by9Fg8x6e5nTJmQV7

Gil took a few valves out to check them. The valves could wiggle a bit in the guides so maybe replace them. The valves were fine but it's not the size I thought they should be. The haynes manual says xu5m valve stems are 7.3mm but the ones we took out are 8mm which is the same as xu5ja and xu9.
Could someone please let me know if I'm missing something here please?
The Haynes manual says the cylinder head should be 141mm tall. Where is this measured from?? I couldn't tell and Gil would too so we can tell if the head has had a skim previously.
Gil also wanted to know if it's a good idea to upgrade the valves to something stronger or would these ones hold up fine to higher revs than standard?
he said the exhaust valve ss stainless but the inlet isn't. Is that correct?
Also When changing to the double valve springs does the head need modified to accomodate these or do they go straight in? https://www.peugeot-tuning-parts.co...springs-retainers-double-xu5-xu9-peugeot.html


After being a bit confused about the valve stem size I have also taken a photo of my pistons to make sure they are what should be in there. Can someone double check these are Si pistons please? There is also a bit of wear on the side. Is this ok? I don't know what unusable looks like

Post a picture of the chamber with some measurement ie width x length. I don’t have one here to measure.

Sorry I forgot to get some pictures of the head before I left it with the machinist.

Sorry for all of the questions. This is a big learning curve and I want to make sure that everything is done correctly.

 

[djvu205]

Dont have any better quality than this but it might help measure head.

 

[djvu205]

Figures for distance H

Measured with cam fitted and torqued down. Different heads are stamped with different numbers which indicates std or oversize cam journals.

 

[GRAHAM WALLIS]

7.3 mm is wrong. Head is same as DKZ. Also, I just use normal 8 valve stem seals without any problem and your head does have the 8 mm valves.