Just a quick note to say this is an excellent thread! Its something I've always wanted to do and is giving me the confidence that, with plenty of research, could do myself.

First question....what issue of Jap performance was it? Im going to try and get it on back order!

 

Very kind offer Wayne! But I managed to sell it on a while ago, went on ebay for around £200 to somewhere in France! With the proceeds of that I bought the second CDB that I am now using, which is in good nick.

 

Glad you're finding it useful! It was the March 08 issue of JP, I don't usually get it but someone tipped me off, the link to buy it is here:
Japanese Performance Magazine - Shops
It doesn't even mention the rebuild on the back issue website, and only says it in small on the cover, but it's a good guide and I found it invaluable. The stripdown was done by Scoobyclinic IIRC.

 

Great...just ordered and subscribed actually!

A quick (hopefully) question, Im after a 2l CDB too..what should I look out for when buying? Other than irreparable accident damage? Where did you buy from? Who did you use as a courier?

 

Well I'm just lucky that I live in the middle of nowhere, and a mile down the road is a largish motorsport garage who have a lot of fast cars in and out all the time, often with track damage or engine failures etc. Hence they often have blocks lying around in the corner doing nothing because the quickest way to get these cars back on the road is a complete engine swap rather than stripdown/rebuild.

Basically, all I needed was the block, so big end/bottom end damage is of no consequence whatsoever. This is assuming you already have a good crank. But seeing as the only 2.0 CDBs around are 15 years old, there should be pleny around with this kind of damage. Pay what you think it's worth bearing in mind condition/history. I see CDBs come up on ebay every now and again and they always fetch several hundred, but to pay that much I'd want it guaranteed that there was no damage to the block casting whatsoever and I'd want some ancillaries on there to be able to sell on or reuse, i.e. water pump, sump, oil pump, possibly oil cooler, pistons, rods etc.

Obviously to get my two CDBs I just drove up the road, paid cash and slung them in the boot. But if you need to get a courier a bare block is not difficult to pack up at all if you have a decent size box. A whole bottom end including sump etc is more tricky. I use Interparcel to pick up anything I need delivered. For £9 you can deliver anything up to 32kg in 48 hours. A CDB is around 25kg.

 

DECISION TIME! After a lot of deliberation i.e. low budget vs. future-proofing, I've decided to convert my standard v3/4 heads to STi3/4. I'm porting and polishing the heads over the next few evenings, then when the new valvetrain comes I'll fit that. The valve seats should be OK with just lapping in. The existing WRX valvetrain was all OK, except for the exhaust valves of which a fair few were worn on the sealing face and would need changing. Standard OE valves aren't cheap and if I were to replace them for Supertech Inconel from Zen, I'd need to do the whole lot. So I'll see what the STi exhaust valves are like when they arrive and make my decision (i.e. Inconel vs STi sodium filled) about whether they need changing.

 

Ahh slightly different situation than me, I'm using my UK Turbo as a base (going to be one hell of a sleeper!) so need the bottom end, block, heads etc. Which means bottom end is a problem for me. Im basically thinking that if I can get a couple of CDBs cheap enough I can take the best from both and move on whatevers left over to keep costs low.

Is there a certain age of CDB that I should be looking for, obviously the later the better? Or are any of them pretty good.

PM on its way

 

Ollie,

I'm too looking about for a CDB. I have a feeling that the early cars (RA and STI's) had them, but I dont know if they all had oil squirters to cool the pistons.

You can have one resleeved to make it a 2.5 if you wanted to.

Any block I buy I will have inspected by a reputable firm before building anything as it would be false economy not to.

Wayne.

 

I think early WRX's had CDB's too, i believe mine has a CDB as it has the usual hashing on the block surface? (93WRX)

Dave

 

Ollie, all the CDBs will be old so I wouldn't worry too much about particular years. The hashing above the oil cooler and on the bellhousing are the giveaways. As to whether they have oil spray or not, well I've had two now and they both had oil spray jets. Maybe it was only the Type RA ones that had these, I can't say for sure.

Buying up a couple of CDB short blocks and using the best bits then selling on what you don't need was a very economical way of doing things for me. I ended up with the blocks almost paying for themselves.

 

Ok cool, I've just had lots of thoughts about this....I think I'll take it off this thread and PM you instead though...as it is your thread and not mine. But thanks for the info so far

 

No problem, always happy to help.

STi3/4 valvetrain, pistons and rods are expected this week...

 

I've spent an hour or two over the last week doing a port and polish job on my WRX v4 heads, soon to be converted to STi spec. Using a couple of different wire brushes, small flapwheels, sanding rolls and polishing felts with my drill, I've now got one head 'done':

• removed as much carbon deposit as possible from ports and chambers
• matched the inlet ports to the gasket lines
• smoothed out the inlet ports, mainly getting rid of casting flaws but not polishing
• smoothed and polished combustion chambers to the best of my ability and tools

Here are the results.



Inlet ports as they were below. Note the very rough surfaces with blobby 'rocks' and visible casting seams running all the way down:



And now with a quick porting job done - gasket matching and light smoothing of casting flaws, but keeping the unpolished surface that inlet ports need:



Combustion chamber before cleaning up and polishing; again you can see how rough the bowl area between valve guide and valve seat is. There is a very noticeable step on the long side bend just under the seat. The short side bend (which you can't see) is actually pretty smooth already and doesn't need hardly any work:



Cleaned up combustion chamber with a light polish, bowls under seats came up well too:



OK it's not the same as the £600 RCM WRC-spec port and polish, but I'm pretty pleased with it for an hour or two's work, and it can't do any harm. With a bit of luck it will help to make more power by giving my turbo by breathing a bit better than normal. With the STi3/4 valvetrain going on it should make a good pair of heads. Ultimate aim is to make decent power without having to thrash the turbo.

 

Another thing to do is to knife edge the port divider (pic 3).

 

Yes I was going to have a go at that, but haven't quite got the right tools. I've got a few grinding stones that could easily do the job but I'm worried that they'll chew through the aluminium too quickly...

 

for porting kits have a lok on deamon tweeks site u used the one they sell and go a good result

these are sti2 heads that i done with the deamon tweeks porting kit

 

Nice! Did you leave the valve guides in?

 

http://www.demon-tweeks.co.uk/produc...code=MSD260001

or

http://www.demon-tweeks.co.uk/produc...code=MSD260012

Adding that to my list of bits!

 

yep left the valve guides in

 

OK I'm on a mission to knife edge the inlet ports... In other news, my pistons, rods and head gaskets have arrived from CDF Racing. Pistons are forged Wiseco, 92.5mm (0.5mm oversize) K576M925 specific to the v1-4 block (http://www.wiseco.com/Catalogs/Sport...ruToyotaVW.pdf)



Forged steel Eagle rods CRS513753S3D (what)



Cometic 1.3mm multi layer steel head gaskets (Sport Compact Gaskets)

 

good luck with this Nick . Look forward to seeing your progress

 

tatsy looking bits of kit, I'm looking forward to watching your engine grow...good luck

 

Great thread. I've just started stripping my engine out. Definitely want to watch this to the end.

Keep up the good work

Chris

 

You're using the wrong thickness head gaskets!

 

Cheers for the input. What's wrong with them Paul? I was told the Wisecos for the early car are supposed to come 0.013"/0.3mm over the deck, recommended gasket is 0.051"/1.3mm. Where have I made a mistake?

 

Measure the deck height before you proceed, as part of a dummy build. You may need to skim the block (check surface with flat whetstone), before you know it things can be a little tight.

 

OK well I've checked the decks with a long spirit level and a steel rule in every direction I can and they seem flat - or at least I can't get a 0.05mm feeler through. The deck height seemed OK last time I measured, but I'll check all round again. Still need to check the heads for flatness.

So basically, the 1.3mm could be OK, but I just need to check my measurements first? What's the optimum piston to head clearance I'm aiming for? And what's the minimum I could get away with?

 

Block has now gone off for a 0.5mm overbore at a local place (keeps cost right down) along with one of my pistons. Recommended clearance is 0.0025"/0.06mm so that's what they'll get.

 

Wot a great thread ive loved reading this and will be a great help to people doin rebuilds that have never done one before

 

bttt