Another 205 8v thread

flock

flock

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Fellow Frogger
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So, I thought I could get away with a casual rebuild of my spare DFZ. Turned out I would need to deck the block and liners as the chamfered sealing face was corroded from the flat right the way down. I kept the pistons and crank, which has just been checked over and polished keeping the std/std journals.

In my due haste trying to get a smoke-free engine to get down to 2 regos with upcoming baby no1, the current DFZ in the car was ripped out. I suspected it would have had more frequent coolant changes even though it has 100k more on it. Sure enough it isn't too bad but I have work to do:

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The machinist is too busy with other people's messy projects so he told me I should be getting some Devcon Aly epoxy. Theres a 500g pack of 10610 Aluminium putty for ~$150, or 184g pack of 19770 Fasmetal 10 for ~$50. Both are almost identical in properties on the spec sheet, apart from chemical resistance. I'm still unsure as to why there is a wet and dry max operating temperature of 49deg and 120deg respectively.

If anyone has repaired one of these alloy blocks with epoxy please chime in. The machinist has said he has seen far worse on Alfa engines that have been repaired and are still operating today.

While I waited for the engine to get blasted I went about cleaning the engine bay.

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Brake fluid had managed to lift the paint under the clips for the hardlines but didn't start rusting yet. Interestingly I found the start of rust on the seam above the exhaust. The same seam that was completely rotten from wheel to wheel on my old car.

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A bit of rust converter a rattle can and clear engine enamel on the tunnel, the bay is the cleanest it's ever been.

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I still need to think about the head. I've got an Si head, a virgin DFZ head and another DFZ head (from this engine) that's 1mm shallower than the virgin head. I don't think I have the appetite to deal with 10.5:1 CR on a street engine, but if I am getting a valve cut job, can the machinist not mill the chamber to increase CR and thus retain the slightly bigger valves of the Si head?

Since the skimmed head has about 5cc less than the standard DFZ head that would bring its volume to an estimated 44cc with a 1mm gasket so I've effectively been running 9.1:1 - might explain why the dizzy advance was blocked off when I got the car but I've never detected pinging on 95 since I reattached it.

More to come, hopefully..
 
Well, I decided to take the engine to an aircraft welder. Amongst the aero engines, he had a Porsche M28 sitting on a bench. Apparently he had to take matching alloy material off another part of the engine to use as filler on the deck/liners. That was enough to trust he wouldn't go in guns blazing.

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Not a bad job for half the price of the smallest, purchasable quantity of Devcon. I might need to take off the tiniest of dags that were deposited on the flat face, in case it affects liner protrusion. The next question is do I worry about about filling the rest of the flat and the chamfered edge where there is still pitting.
 
The o-ring makes contact on that chamfer. If it were mine, I'd butter up the o-ring with 1211 and hope for the best. I've done this before and it works a treat. If it were someone else's, I'd get it machined.
 

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In regards to head selection, using the Si head (but not the cam) is a no brainer. A CR of 10.5:1 is not high for 98RON. Just get three angle seats cut and remove the obvious dags in the ports, up to 25mm under the seats.

Swap the centrifugal springs in the dizzy, to something a tad stiffer. They're easy enough to change and test with a timing gun.
 
There is also JB weld that claims 250C temperature resistance.

Can't you get a good block? Over east people were saying they were a dime a dozen.

Welding aluminium is a pain in the butt with all these unknown alloys but your decision to go to the aircraft mechanic was probably the wisest. I did the same when I modified my sump.

If that were my block and I did not have a chance in hell of finding a good one I would have that properly repaired. That is build up weld on the seat(s) as needed and have all of them machined again in one setup. A good machine shop should have no problem doing it but it does take some finesse in setting it all up.

Either way, I would measure that block now for distortion, you never know what these things get up to.
 
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Belzona is a much better product than Devcon or JB Weld.
 
Shlitz this is the second block I've torn down, and I'll be happy to save a block from the scrap pile. I'm all for agricultural fixes, but the number of Youtube videos using JB weld in novel situations, and its 2 page spec sheet doesn't inspire confidence. Belzona, on the other hand, would definitely be the go if it wasn't so bloody expensive. Anyway, if it fails, I'll skip the bs with XU9s and save my pennies for a de-VVT'd EW10 in the future.

Peter - while I've got you here:
- Once you've smeared the rings, do you clamp the liner down while the RTV sets or just sit it on top?
- Headgasket, do I go for max squish with a 0.68mm cometic or go on the safe side with a standard VRS kit item?
- I'm aware you don't do cams anymore. Sorry I took so long to finally pull my finger out, else I would have commissioned your services. Would I be ok with the 4900365 Catcam for that CR? As long as it idles and has good manners I'll cope until Matthew gets his speeduino motronic ECU ready :cool:

Matthew has kindly given me some ACL rod bearings and a 6 bar spring. Looks like I'm going to take my Si head to the shop to do the work, thanks for the reassurance. Once I know what cam I need I'll make an order on Pug1Off as I still need to source mains and rings quickly.

On another, controversial note, I'm swapping my BE1 for the Si BE3 I have. I'd like to convert my BE1 but I'm fairly sure I ruined it when I kept having issues with the clutch. The oil was full of metal and I had only driven it about 1000kms on fresh oil.

Also obligatory restoration thread photos: No wonder I was going through so much oil.

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Si box has a horrible gap between 1st and second. I find in my otherwise stock Sis that the Mi16 box makes a huge improvement.
 
Yes, you need to keep the liners bolted down, while the 1211 sets and until you're ready to fit the head.
I'd use a std. 1.3-1.4mm head gasket. The thinner Cometic will push the CR over 11:1.
There are other local cam grinders, before you spend lots of money in the UK. What oem 8V cams do you have at your disposal?
The 4900365 is a good choice however, very similar to the D6B cam.
Si box would be my last choice. Surely you could swap some gears around? The Si case is an excellent base to build a good BE3. Send it down to Adrian if you're not confident.
 
Will not gift you the Mi16 box but between the Be3 Adrian built with the quaiffe , a xsara VTS box and a Mi16 as well I am not needing one of these! The Quaiffe stays here too!
 
My thinking as well will make the best of what I have and go from there, then onto flock!
 
Only cams I have are 2x DFZ and the Si. If I can get away with a regrind, I'm all for supporting local trades.

Before we go down the rabbit hole of gearboxes, just to keep things within scope, this is purely for street/weekend warrior use. I've spent the last few weeks testing power transformer differential protection relays with mismatched ratios, so forgive me if my brain can't comprehend when it has to switch to ratios of the mechanical kind. So I've used a simulator for my sake of understanding...

Since I'm not looking to save seconds off my 0-100 times, I can't see myself worrying about the slight differences on 2/3/4/5 ratios between the boxes. This leaves the issue of lower 1st and FD. There is about 6% difference to the GTI BE1 first, so is it really that bad if that is what I have been used to? I can foresee it exacerbating the jarring fuel cut-in around 2000 when you're crawling around in 1st if I keep the Jetronic for a while.

Final Drive is obviously where the acceleration is felt, but a 4.4 FD is going 3400RPM @110kph, whereas 3.9 FD is going 3000RPM so that's one bonus of the more pedestrian Si FD. And assuming the 2000-6500 range is the sweet spot for all the Ph1 cams, the engine is still 'on-cam' as it goes up the rev-range. I'd be lying if I said my 205 couldn't do with more acceleration, however.
 
flock said:
Shlitz this is the second block I've torn down, and I'll be happy to save a block from the scrap pile. I'm all for agricultural fixes, but the number of Youtube videos using JB weld in novel situations, and its 2 page spec sheet doesn't inspire confidence. Belzona, on the other hand, would definitely be the go if it wasn't so bloody expensive. Anyway, if it fails, I'll skip the bs with XU9s and save my pennies for a de-VVT'd EW10 in the future.
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I am not advertising for JB weld, just suggesting one option I don't really have much experience with so the best I can do look at the spec sheet. Like I said, none of these are ideal and on paper JB weld has the highest temperature tolerance.
 
flock said:
Only cams I have are 2x DFZ and the Si. If I can get away with a regrind, I'm all for supporting local trades.

Before we go down the rabbit hole of gearboxes, just to keep things within scope, this is purely for street/weekend warrior use. I've spent the last few weeks testing power transformer differential protection relays with mismatched ratios, so forgive me if my brain can't comprehend when it has to switch to ratios of the mechanical kind. So I've used a simulator for my sake of understanding...

Since I'm not looking to save seconds off my 0-100 times, I can't see myself worrying about the slight differences on 2/3/4/5 ratios between the boxes. This leaves the issue of lower 1st and FD. There is about 6% difference to the GTI BE1 first, so is it really that bad if that is what I have been used to? I can foresee it exacerbating the jarring fuel cut-in around 2000 when you're crawling around in 1st if I keep the Jetronic for a while.

Final Drive is obviously where the acceleration is felt, but a 4.4 FD is going 3400RPM @110kph, whereas 3.9 FD is going 3000RPM so that's one bonus of the more pedestrian Si FD. And assuming the 2000-6500 range is the sweet spot for all the Ph1 cams, the engine is still 'on-cam' as it goes up the rev-range. I'd be lying if I said my 205 couldn't do with more acceleration, however.
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Even just driving around the street I found the 1st to second gap really annoying.
 
Sis don’t work below 3000 so the 4.43 is great as you can stay in the power band at the 100 k limit
 
The Si cam is useless. You can regrind the DFZ cams. You'll end up needing much thicker shims, but they'll still be within spec. A better approach is to find an XU10J2 cam. They have a lot more lift to begin with.

I'm with Graham. I had the 3.45:1 1st gear in my Mi16x4. They used it to help save the clutch but the gap to 2nd is horrendous.

Whilst the VTS and Mi16 boxes use the 4.43 cwp, they also use a longer 5th. Thus the overall ratio in 5th is very similar to the S1/S2 GTi 5th. ie
4.43 x 0.76 = 3.367
3.94 x 0.865 = 3.41

I still think that S1/S2 GTi box is the best overall, but they're a bit thin on the ground now. I should update this with the later gearboxes:

http://www.taylor-eng.com/gearing/205-405gearing.htm
 
If you want to build a box let me know i can give you a hand. BE is the easiest gearbox to pull apart and put back together. Matt has the Special Tools you just need a press. I have the pullers and sockets. I would stick it in first and try it though.
 
My head guy he said get the cam first and he can do everything including replacing the guides, buckets, shims if needed. I didn't ask about 3-angle cut but I assume that's a given, will confirm. I spoke to Tighe Cams, they estimate $420 for a regrind+harden. The owner told me the a regrind of the original would last longer than a catcam or blank. Getting a blank from his supplier in Turkey is just not economical if I can get a catcam for $460 delivered from Pug1Off. Thoughts?

I'll put a raincheck on your Xsara box Matthew, thank you. In 2016 I did put new bearings in the BE1 and its only done maybe 2000kms on that box, so could also be swarf that was picked up as it was the first time I had ever done bearings in my life (there was no forcing pin on the bearing separator kit so it just tore shreds out of the centre of the shaft as I spun it round).

Either way I'll stow it away and chuck the Si box in while I focus on engine. I don't want to mess around at this point if I can just revisit in future with a simple gearbox swap once the BE3 clutch is on, but I won't scrap anything just yet. Thanks for the offer James, I was definitely going to get you around to give us a hand sometime with getting that PAS installed. Apart from the boots and hoses is there anything else I should replace on that rack as a matter of preventative maintenance?

Mains and new thrust washers have come in, just looking at the total seal catalog now, there's way too many options. The pistons I pulled out of the current engine had what looks to be either chrome or steel rings. Top ring was plain rectangular, second is barely noticeable but looks like napier on both top and bottom faces. Not sure what the intention was but they look hardly worn and if they were chrome I wonder if they even seated at all as the bore looked factory honed.
 
Here's some photos of the rings. The virgin DFZ rings have the defined napier where the current DFZ has a very subtle parallel profile.

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