MTDI+Common rail

[famous phil]

Hi all ,after much searching with the help of a local Bosch diesel specialist not much in the way of a suitable pump has been found , a discovery pump looked promising but for the injectors in the TDi that I have will only work at the lower pressure rendering that pump no good for the job , so I had no choice but to get some new tooling as my tooling is for the old in line pumps , I've been building a common rail engine conversion but thought I should try and sort out a pump for my pals TDi bus , he's had an engine sat for 12 years with only 32k miles!!!!

first task was to prove something to him , with a damaged Golf tdi of the same age as the tdi engine in his camper , I said open the doors and bonnet then go make some cups of tea , I removed the engine ECU and placed it on the seat then locked the doors I then set to and hot wired the pump ( I knew this from proving the fact to a vehicle security specialist many years ago ) and having it running in under 15 minuets ( 2 minuets less than a sprinter and jeep Cherokee of the same age ) , you should have seen my pals face when he returned with the cups of tea , seeing the keys in the door and ECU on the seat

more at tea time

[famous phil]

We've fitted my MTDi pump to my pals camper and have had it running , this is where we've found a problem due to his engine sitting for so long there was white smoke - unburnt diesel - on checking it was found that two cylinders were causing this -rusted valve seats and valves - much to the disappointment of my pal ,, at first he thought it was down to the pump I said not a chance its calibrated to run this type of engine , after a bit of fettling we fitted my pump to the golf fired it up and left it to warm up while we cleared another area in his shed for the camper ,

we then checked the golf throttle response it was a little slow and the engine was not very warm so upped the fuelling screw 1/8 of a turn , this more or less made it rev the same as when fitted with the ECU & pump still with very little smoke boost pin is turned for least delivery of fuel at the moment until we get it set up on the exhaust gas Analise , We then looked over a later Tdi engine that I'd bought with a rod through the block to see if any auxiliary parts might work better in his camper coming to the conclusion that the alternator might be the only part ,This engine had the cam driven vac pump not sure why they changed to this type as apposed to the one in the distributor position , maybe they've built the later engines without the intermediate shaft , I might fit one of these late 90's 1.9TDi's into my splity having been developed from a 1.5 petrol they're not a heavy engine which will be more suitable in the split

I've also been collecting parts for a 5cyl 2.5TDi conversion to MTDi pump , this ones taking a lot of research because there's not much choice when it comes to 5cyl pumps that are counterclockwise rotationally driven so far it's being built using parts from three different types of Bosch pump and quite a bit of machining making sales of this type uneconomically viable , Still need to concentrate on my Common rail conversion which is coming along great just needing to source a few more parts

[famous phil]

new tooling and disassembly/assembly jigs arrived yesterday to aid building these pumps as well as setting up a CNC program for machining some of the internal parts , I've got five TDi pumps here and three have different pressure settings also using different internal parts , the one I'm using for my common rail conversion is 220bar 300bar, this also uses a slightly different profiled camplate

Two that are getting built up today are rated at 190bar which are the same as one fitted to a vehicle yesterday , I've not found one as yet that will need the engine injectors changing ( obviously common rail does )

[camper]

Phil reading through your topic does this mean then you could supply a MTDi pump for a VW 1.9TDI engine .If so the tall gearing wouldnt be a issue then .

[Russel]

The tall gearing wouldnt be a problem?

[camper]

Just to clarify this if you fit a VW TDI with its fly by wire fuel pump the gear box needs taller gearing involving fitment of non standard gear box parts for the engine not to over rev .But if the engine is fitted with a MTDI fuel pump its not such a issue .

[Russel]

No it is still an issue. The TDI produces max torque from 1800 rpm and drops of at about 3200 to 3600 no matter whot pump,setup you use.
You want to cruise at no more than 3000 (preferably 2800) rpm with either setup + the longer gears have courser teeth that make them stronger to
handle more torque than the standard ones.
There is no short cut to going TDI.
Unless you go 1.9TD but this is not a TDI and never will be.
Russel

[famous phil]

Hi I'm still in the development process at the moment and have help from a good friend that works in the design and development department at Cummins they used this same type of pump on some of their smaller engines fitted into Dodge pick-ups ,Bosch specialist went through details and specification for parts to use in a mechanical pump to power the TDi engine .
Problem is to collect all the correct parts for the MTDI to fit into a T25 without the aneroid fouling the engine lid would possibly mean using parts from at least three different types of Bosch pump , to work as near to the original running specifications as possible ,I'm waiting for prices of some smaller parts ,also if a JX type aneroid was not specified this would drop one of the pumps , one that I built last week is fitted to a golf this only used parts from two pumps and a couple of new items costing very little and only very little machining , I'm going to fit one to a T25 to see how much interference it'll cause , then see what can be done to over-come this ,dare say it'll be the same as many AAZ converted T25's so maybe someone will have an answer to this

as Russel at Syncro-Nutz has pointed out the turbo's on the 1.9TDi's & common rail type engines are slightly smaller units than what would be fitted to a normally aspirated engine hence giving lots of low down power ,
if like I said above - possibly one of the pumps could be dropped if the governors were used from the main donor pump this would allow the engine to rev higher even though not much assistance from the turbo is given due to the exhaust manifold turbo bypass valve being open expelling spent gasses back into the exhaust
The common rail engine that I'm converting is also fitted with a smaller turbo if I'm not happy with the power and torque at the higher RPM's of this unit then I'll increase the size of the turbo slightly to a KKK k14 or Garrett T2 these are normally found on indirect injection diesel engines under 2 litre , nowadays found more on engines of 2.5 litre , this makes no difference to the fuel pump as the turbo boost pressure operates the aneroid for fuel boosting ,
not sure what figure people will class as over revving , I'll add a pic below of a four wheel drive car with 1.9TDi running 250BHP at 5500RPM's the guy that built this car and many like it has been into tunning VAG vehicles for as long as I can remember , there are still a few of the older lads that call round to see him in there late nineties golfs/passats that are running above 130BHP with revs of close to 5000 , when these earlier cars were being raced the pump was a drawback, it did not like to rev over 3000RPM but then who'd want there engine to rev over 6000 revs obviously it would be nice to have a taller gear ratio I do a lot of trailer work with mine so not to bothered , will have to see how it works at the end of the day its the same engine block just made into a Di which must be pointed out ( because others will only do so ) adds some extra stresses to the bottom end



rear axle set-up

[camper]

Slightly diversing but i am going to ask this question.Can a TDI engine block be used for a TD conversion using parts like pistons from a AAZ but retaining the tdi con rods and crankshaft.Fitting a AAZ cylinder head .

[famous phil]

Hi, although the blocks look the same some manufactures use a slightly smaller diameter piston in the Di type engines , what you'd need to do is cross reference part numbers and dimensions , gudgeon pins head /gaskets , at the end of the day there are people out there that have fitted the AAZ turbo to the TDi to get the same characteristics
I was going to do something similar use a common rail bottom end lots of work to make a N/A cyl head Di , so enquired about buying an engine at the breakers yard without injectors or high pressure pump the yard owner replied thats all we sell from them vehicles because the engines don't go wrong ! there's a yard full choice is yours £100 an engine to me with very little work and using off the shelf parts I'll convert it to MTDi

There was a few lads many years ago building petrol turbo track cars using the diesel turbo( including TDi )engine blocks a lot being based on petrol to start with using the dizzy position to fit the vac pump ,

[famous phil]

Hi all , as said earlier my pals camper had sat in his shed next to his broken AAZ engine and that his TDi engine had sat for 12 years I thought it would be best to check out his fly-by wire pump first just to make sure that its in a serviceable condition we were very happy with it , I'm picking some shims up this morning because the ones in stock did not add up to the ultra-fine tolerances , the video below shows the pump going through checks

[youthy giblets]

Hey phil does your young lad know you used the bits from his remote controled car to get andys golf motor run yet? was speaking to andy this morning hes really glad you got his pump sorted for him couldnt believe it was 12years it was there seems like 5mins ago