xu5m engine rebuild

A

apitiser

Member
Fellow Frogger
Joined
Jun 21, 2018
Messages
107
Location
Vancouver Island, Canada
Hi, I started pulling my spare engine apart so that I can rebuild it and get a bit more power. The head is off so some photo's were taken.

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

How does everything look? I can get more pictures if needed

There is a bit of corrosion in the head. Is this serious or will it be fine to get filled in then get the head skimmed?
One of the camshaft caps has some pitting in it. Is this rubbish or ok? do the others look useable?

I will be pulling the crank out in the next few days so will drop that buy a shop to get measured and checked.

This is my first time rebuilding an engine and I'm in Canada so I don't have any Peugeot people close by to help so reaching out here.

I'm going to keep adding pictures as I go to the album.

Thanks
 
It looks ok, other than the corrosion in the head. Weld it up and skim. Are you looking to increase the CR? You can skim up to 2mm on those heads. However, this will retard the ignition timing.

As there is significant corrosion in the head, expect to see similar in the block around the liner seats. I get that area bead blasted so the true extent of any corrosion can be seen.
 

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PeterT said:
It looks ok, other than the corrosion in the head. Weld it up and skim. Are you looking to increase the CR? You can skim up to 2mm on those heads. However, this will retard the ignition timing.

As there is significant corrosion in the head, expect to see similar in the block around the liner seats. I get that area bead blasted so the true extent of any corrosion can be seen.
Click to expand...

Thanks for the reply.

Yes, I am looking to increase the CR. I'm going to throw in some 1.6 gti pistons to replace my si set to bump the compression up. I have got some ITB's for the car and want to get a more aggressive cam to go with it but I'm not sure what to order or what CR to aim for. There will be a vernier pulley to go with the cam so that should work fixing the timing with the skimmed head right.

Do you sell cams for 8v engines Peter?

I'm going to do a big order for parts through Pug1off once I know what bearing size but happy to spend some money with ya if you have stuff that can help this engine
 
Depends what fuel you have. What RON/MON? I'd otherwise be getting the CR as high as possible and use Catcam 4900366 cam and vernier. I don't sell 8V cams any more.

You might be able to get 11:1 if you skim 2mm off the head and use flat top pistons.
 
all places have 91 but there are a few close by that have 93 or 94 RON/MON. would that be suitable for 11:1?

sorry if this is a silly question but would that car having a high CR be weird to use for driving longish distances? would it become high strung? I'd like to take the car on some road trips (maybe to California once Covid eases up) and even just driving to local autox events is about 180km away
 
RON or MON? there's a huge difference.

Increasing CR increases efficiency at all RPM's, providing you have the matching fuel. Perhaps pull back on the cam timing if you need more road manners/low end torque. What gear ratios and cwp are you intending to run?
 
Ok, did a bit of googling to find out what Canada uses and It looks like it's AKI (RON+MON)/2. So I think aussie 98 RON is equivalent to 93 here.

I have 2 gear boxes. standard si which I'm thinking about sticking with because it will see more highways (it's just a hair over 3k rpm at 110kph) than track or autox and the there is a mystery box that might have the mi16 cwp but not sure what ratios. Callum had it in his si and it seemed pretty short geared compared to my standard one.
 
That would be a box with 4.43 and Si ratios. Adrian W built it I think.
 
11:1 and 91 MON will be fine.
 
Standard Si gearing is too long. If you want it to go well, you should at least get the gearing to equivalent of a 1.6L GTi, which as 0.865 fifth and 4.06 cwp.
ie
0.865 x 4.06 = 3.51:1

Thus running the standard Si 5th with a 4.43 cwp gives:

0.76 x 4.43 = 3.36:1 ( the same as an Mi16), which is still longer than a 1.6L GTi.
 
Just putting an Mi16 (actually S16) box in my otherwise stock Si made a big difference. MUCH better on the highway as previously at 100 km/h you were below the point at which the engine starts to work, 3000rpm. Would be alright if we didn't have speed limits. The car I've just built now also has an Mi16 box.
 
apitiser said:
Thanks for the reply.

Yes, I am looking to increase the CR. I'm going to throw in some 1.6 gti pistons to replace my si set to bump the compression up. I have got some ITB's for the car and want to get a more aggressive cam to go with it but I'm not sure what to order or what CR to aim for. There will be a vernier pulley to go with the cam so that should work fixing the timing with the skimmed head right.

Do you sell cams for 8v engines Peter?

I'm going to do a big order for parts through Pug1off once I know what bearing size but happy to spend some money with ya if you have stuff that can help this engine
Click to expand...
I've got GTi pistons plus a .9mm copper head gasket. Works out to around 10.8 to 1. Has fairly big Tighe cam, seems perfectly OK to start up and run but need to run it in somewhere. Booked in for tuning on the 27th of next month, second day out of lockdown hopefully.
 
PeterT said:
Standard Si gearing is too long. If you want it to go well, you should at least get the gearing to equivalent of a 1.6L GTi, which as 0.865 fifth and 4.06 cwp.
ie
0.865 x 4.06 = 3.51:1

Thus running the standard Si 5th with a 4.43 cwp gives:

0.76 x 4.43 = 3.36:1 ( the same as an Mi16), which is still longer than a 1.6L GTi.
Click to expand...

It's going to be a bit too costly for me to get a 1.6 gti gearbox to canada right now. All my money for the car is going to be getting put into engine parts, I'm also getting a quaife and I still haven't decided what's happening with engine management and loom so will have to make do with the two boxes that are here.
 
GRAHAM WALLIS said:
Just putting an Mi16 (actually S16) box in my otherwise stock Si made a big difference. MUCH better on the highway as previously at 100 km/h you were below the point at which the engine starts to work, 3000rpm. Would be alright if we didn't have speed limits. The car I've just built now also has an Mi16 box.
Click to expand...

The speed limit on highways is about 110, more in America so the si has been quiet and comfy on the highways.

There are mi16s floating around for sale in north america so I could possibly buy a gearbox from one.

I'm looking forward to seeing the results from the tuning. did you get any work done to the head or is it standard minus the bigger cam?
 
Got the head from Dave in Brisbane. He used it on a 1.9 litre Citroen BX. Slight amount of tidying up on the head.
 
apitiser said:
It's going to be a bit too costly for me to get a 1.6 gti gearbox to canada right now. All my money for the car is going to be getting put into engine parts, I'm also getting a quaife and I still haven't decided what's happening with engine management and loom so will have to make do with the two boxes that are here.
Click to expand...
The gearbox from Cal would be almost the same. Probably the only difference is the low first gear in the Si.
 
I agree with Graham. And given you're looking for more road manners and not intending to rev it as much, I'd use a smaller camshaft than what I suggested. eg Catcams 4900365 or maybe Piper P16BP285.
 
Peter, one of the main reasons I'm doing the rebuild is to end up with an engine that can rev up high but can do highways and road trips. There is so much distance between everything in North America I thought the one Callum sent would work out well with that.

I finished work early today so went to my garage and tried pulling the bottom end apart. The middle cap that holds the crank doesnt want to come off. are there any tricks to getting this off? also the flywheel side cap doesn't want to come off either but that might be from the crank seal sticking. other than that everything has come apart really easily.

Some photo's have been added to the album showing wear on the bearings and crank. From my inexperienced eye the crank looks fine I have no idea.

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

Can someone let me know what the deal with this sump is please? It's steel and there is a sump spacer. I'll probably use my sump that's in the car because it's not bashed in like this and the car still has AC.
 
If its like the Mi16 there are bolts coming in either side in the block / shell. Look carefully.

Lovely place to live to, visited about 12 months back.
 
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