Turbocharger

A dump valve throws away your boost to avoid surge when your massflow requirement changes suddenly - eg snapping the throttle shut on a petrol engine. They're not normally useful on a diesel because the massflow doesn't change so quickly - no throttle butterfly. However, I have a surge 'feature' on my VGTdi when coming quickly off the throttle because the vanes can't respond quickly enough to this pressure change and it surges momentarily. However, because I haven't got the calibration sorted yet it surges under load too Your valve sounds like a bleed valve - when the manifold is at 1 bar and the wastegate would normally open, the wastegate only sees 0.5 bar and stays shut to build more boost. If you're throwing it away, I'll have it!

I know a mate of mine was there, he rolled on the first section apparently!

I appreciate I'm sitting here in my armchair with a broken LR outside making comments but... why have you both gone for a cage with the bends in the main hoop to clear the wheelboxes? These bends will weaken the cage and you're both running a trayback, so no wheelboxes to clear.

Good call Tony - I'll do a compression test and a blowby test. I had a grownup come and look at it today too, he reckons it might be within sensible limits for blowby (from the rings). It's hard to tell how much breather gas I have compared to a normal Tdi, since they normally vent into the inlet. If my test works I'll post up the method and results. James - not bad for a three page thread, that's the first mention I think.

Now I've slept on it (not literally), if it's breathing this heavily is this likely to be piston rings or have I put the gasket on wrong somehow and it's blowing between one of the bores and an oilway?

But is it the same strength?

Lifting eyes are dead weight but I'd only lose them otherwise. I worked away for most of this week but finished it off today, including my tarty paint job: but I'm not entirely pleased with the result. Just to recap, I had cracks in the head: and evidence of water having got into the bore of #3 cylinder: Now it's running but breathing heavily: see . What've I done wrong? I can't see how the head could be contributing to heavy breathing (since I remembered to fit the valve stem seals anyway) so I guess it's coming past the rings on #3 and so the whole thing's got to come apart again...

I'm with Bell, they have a long list of my mods which runs to pages, and they came back to clarify some points with intelligent questions at renewal time. So far, I'm pleased with a service which, at best, costs me money for nothing...

Screwfix are doing some good deals at the moment - Ni-cad batteries are about to be made illegal but nobody's sure when the impending legislation is coming and whether it'll be retrospective so everyone's punting their NiCad stock out cheap while they can still sell it. For £80 I got a cordless drill and a mains drill, both DeWalt. Quite impressed with both so far.

I stopped somewhere in France to apply my headlight 'beam benders' and a Disco skidded to a stop to help me with whatever my problem was... I'll give a wave or a nod to likely-looking Defenders and Series trucks, maybe RR Classics.

I built the head up and fitted it today. I bought a number of small bits including the dowels above - seemed easier. I forgot to buy the dowels that locate the head into the block but one stayed in the block and I managed to delicately rescue the other from the old head - it seems to have gone together ok. Some nasty bits of the casting: Rather than get aggressive with porting for huge flows (and end up touching the water jacket and scrapping the head) I decided that discretion was the better part of valour and I mostly just tidied up rough edges, smoothed out the lumps and took out the flashing in the casting. I've left the valve guides at standard length and I've tried to leave the swirl ramps as they were. Here's an example of the pic above after my tidying: In the same vein, I cleaned up the valves: This is getting silly, it's only good for 4500rpm and I'm not going to open the pump up any more: Next, two happy hours of this: Then dressing the head with studs, thermostat housing, blanking plugs and heater bits. I annealed all the copper washers that were going to be used in the build: Heater plugs and injectors going in. The injectors seal at the bottom with a copper washer - this should have the pointy bit upwards; slide them down a long screwdriver to make sure they don't flip over on their way down. Use the tapered end of a long wooden pencil to pull the old ones out if you have a used head. and then I built up the valves, twice. Note at this intermediate stage, the new shiny valve stem seals which should be in the head now. Don't put the rocker shaft in now either, you'll have to take it back out to get the pushrods in. Then, some considerable torquing later, the head's in place. I have to admit - while I was waiting for TroddenMasses to fetch me his torque wrench because I'm too lazy to buy one in the week, I had an attack of feminism and tarted up bits of the engine bay. Andy M won't be pleased, none of it's colour-coordinated but I like it. More photos to come.

It might be worth a chat with your local bus workshop. We do all our trim in-house but our competitors use a local "Timmy the Trimmy" or similar.

The number plate doesn't suggest it's a 1972 car, even if it's a private plate. To be fair, externally that's pretty toned-down for Bellargio's normal efforts...

Wishing you'd still got the hardtop now Nige? My best effort was moving house as a student - no money to pay anyone and all my stuff from Brighton back to Bath: Note the lean from the high CoG and the weight in the back putting it on the bump stops...

Steve - I think you're belittling the work to make a VNT work well with an engine - either I'm making a meal of it or it's really quite involved, but it's certainly not a bolt-on job.

Yup - a tick in the box from me. I remember my school workshop had a sticker on the office window: "Now new ideas have a place to happen".

Yup, I guess the auto box was ditched because, with a stick shift there's no computer arguing about ratios and wheel speed sensors... I've never done it but I guess with pistons going up and down and some spark plugs to be tickled it'd be a straight-up job for Megasquirt? If you're fooling the OEM ECU then fair play, I take my hat off to you - I can't even get a different turbo working on my 300Tdi!

I expect that improving the flow at all will have a very marginal difference, but if the rough edges are still in the casting, I'd know and that'd bug me. Anyone know how much material is behind the 'swirl' lumps before I find coolant? Any clues how I get the dowel for this hole out of the old head? I cleaned it up with ether and heated it to expand the aluminium to grab it with pliers, but predictably that just gave me a cylinder head that was on fire. (Note the lovely incomplete casting across the back face of the valve chest)

They'll bolt straight on. The nuts look different but there's a steel cone at the bottom of the nut to locate the steel wheel - an 'alloy spare' was an option on the Disco and for the vehicles with a steel spare, they made the nuts able to fit both (or else you'd be stranded with a jack and spare wheel, unable to bolt the spare onto the car!)

A couple of pics for those who didn't make it: Mechanical horse + rider Horse's Ass (or donkey) Me on Si's electric bike My mate Simon on Si's Skateboard of Impending Pain

I saw a LaSalle headlining in a Series truck and I was utterly underwhelmed at this big GRP thing.. maybe I'd missed the point

James, if the sump route isn't appealing then the flex plate bolts on my 300Tdi can be wiggled out with a spanner through the starter motor hole. I've got an adaptor plate which might give me more room though but it's worth a thought?

Well, I don't know what a Paddock or Craddock head look like inside but mine's <ruff>, like the dog! Big bits of casting flashing, incomplete machining and it's quite a porous casting around the rocker chest. None of it's bad enough to send it back (yet) but, after buying the cheapest head on the market, predictably I'm not impressed. There will be some fettling and scooping with a Dremel before I can start lapping the valves in, that's for sure.

I've re-uploaded the railway station clip , I can't re-edit my old post. YouTube seems to make the conversion from mp4 rather jerky which is a shame, it plays very well at this end.Edit: I've put it on Facebook too, but I don't know if others will be able to see it there. Seems less jerky though.

Well, I spotted some young hoodlums riding round on your skateboard (rather quickly and irresponsibly - couldn't you limit it to 5mph or something?) - I took the opportunity to video it , in a railway station and .Top weekend chaps - thanks to Superpants for pointing it out, well worth the trip. I'll put some other pics and vids up tonight.