uk66fastback
New member
I'm constantlly amazed by the knowledge and dedication of people on this site!
Building a 400bhp+ 2.5 ltr 944 Turbo
- Thread starter PSH
- Start date
Evening guys.. a small update...I've been a bit busy with other projects... so we now have an installed clutch, new motor mount fitted as is the water pump I had to first machine up a clutch alignment tool ..I machined it as to be a precise slidding fit in both the spline and the spigot bearing, of which last half was machined undersize for easy retrival. This worked very well, in fact my son commented that it was better than his alignment tool... well it was custom made...
here's the tool... just straight turning..
so what's next.... well short block should be back in very soon... next week I'll drop off the head for new valve seats and to be skimmed, plus the wastegate needs a new valve seat fitted. Pete
morning guys Just some info regarding the wastegate, previously I had stated that the wastgate seemed to have a valve seat matching the exhaust on the head and that I was going to replace it using a seat that i already had in stock. Well the head and wastegate were taken to the engineering shop yesterday to have the work done, later in the afternoon i received a call informing me that there is no separate valve seat fitted, the valve is seated directly in the housing, it just looks like there's a seat fitted. The cracks that I had seen do in fact continue further than the seat itself clearly visible now that the housing has been cleaned up, the good news is that the machine shop re-cut the seat anyway and believe that it will seal. Now since money is tight i'm going to keep the wastegate and see how it performs with the newly cut valve seat, i can't find any reference to these WG's failing due to cracks in the housing, yes I know about studs breaking but that's a different matter and one that hasn't effected me so perhaps this may be a common issue that's not known about due to so few being stripped down? The deciding factor is that if the WG does fail in the future it's not a big job to replace it, say worse case scenario with seized studs no more than 30 mins on the ramp and more importantly that it won't harm other components, I have the new diaphragm and spring to install so fingers crossed all will be ok. I'll of course report back any problems if they arise to help other 944'owners once the car is back on the road.. Pete
Cracks in the wastegate are common, It was often mentioned as a reason for buying a Tial against going with the refurbed/modded lindsey units - if they hadn't cracked it was likely they would soon against a cheaper brand new Tial which I have never heard of cracking - though they did have issues with adaptor plates not sealing.
hi guys I've been busy of late on the car... i won't go through all the details as i don't want to bore you guys so will just list ( if I can remember) what has been done since the last update end of last year. One picture though from a couple of weeks back... the engine is now back in the car...first time in nearly 4 years...where the hell did that time go...lol
recent work done. Head rebuilt (thanks Rob for the exhaust valves..PM sent) new cometic head gasket ordered as a special from the US...5 ply 101.5mm bore and 60 thou thick new belts, rollers etc fitted alternator rebuilt and polished New A/C compressor fitted New reservoir/drier ready to fit Seals changed to R14a and pipework tested Turbo is at universal for a rebuild, expected back next week vitesse chip/board sent back to John for software upgrade to later V-MAF+ coding and new MAP sensor, also extra image coded for 55lb injectors for running in and when I want more economy and less than 400BHP and 80lb injectors image for dyno program when engine ready for max power. 3" free flow exhaust + 3" turbo downpipe oil cooler fitted Rad and fans fitted wastegate rebuilt and fitted with new diaphragm and spring, shim machined up and fitted to increase spring pressure new clutch fork pin machined and fitted starter motor fitted Jobs to do fit steering pump system build custom air intake system build custom IC hard pipes....( son has bought a large hydraulic tube bender kit for this and the air intake job plus anything else that may need doing up to 3" pipe) fit turbo fit vitesse chip/board fit new seal kit to throttle body and hone out inlet manifold to match head ports...undecided as to polish or paint manifold clean and fit 55 lb injectors/fuelrail fit new hatch , hatch pin, sunroof and window scrapper seals new battery to fit brake check and overhaul where needed refit all suspension items and under trays fabricate new wiring section for the starter motor and lighting circuits...the engine loom was all replaced with LR items not long before the car was taken off the road. 4 new tyres there's probably a few other bits and pieces that I've forgotten but we reckon a good weekend minus brake work would see the engine ready to start...won't be this weekend but hopefully should be before the end of the month. once running I need to take the car to my son's work to get it up on the ramps and deal with the corrosion on the drivers inner seal... from what we can see it's not too bad.... a day should cover it and then it's off for it's MOT.....fingers crossed.... Pete
Pete
pauljmcnulty
New member
Pete, the day you do that we'll let you know! [
] Until then, keep the updates coming.
thanks everyone......she's getting there that's for sure...hope to get the turbo back in a few days... regarding the turbo this is an interesting story, afraid i didn't take note of mileage but would guess around 30k from it's last rebuild, this being the second since it's been on the car....as some will remember I had a loss of power for some time although i only noticed it on the dyno, not the road...probably because as a rule I don't tend to push the car that hard. Other than being down on power the graph also showed a big increase in the IT temps, from 13/14 on the previous two good runs to high 30's to over 40 on the last. Only when I stripped the car down for this rebuild ( due to pulley bolt coming undone) did I begin to find reasons for this loss of power....first thing was discovering there being no filter within the cone of the Pipercross venon air intake...at the time I thought this was my fault in some way, only recently did i discover while looking for a replacement filter that these are bonded in at the factory and can't be replaced....if I had know this at the time I would have been approaching pipercross for the damage to the engine, it seems I'm not the only user to have this happen. So the foam insert had been sucked into the engine, damaging the turbo...bent intake impeller blade and chipped hot side blade too, not to mention the state of the bearings hence the rebuild. The other consequence was the intercooler getting clogged by the remains of the filter, not only did this increase the heat but it also damaged the internals again only discovered when it was pressure tested prior to being upgraded to a stage 2 IC by Tom of this parish. while here i will mention something else that I have discovered regarding the crank bolt coming loose, something that seems to have hit other 944 owners over the years, we suspect that this may be due to the bearings on both the A/C compressor and the alternator failing. In particular the A/C which on further investigation it was discovered that it was possible, turning the pulley by hand to lock up the clutch which was in a very sad state. We believe that it's possible due to the A/C and alternator issues that this at times when the clutch locked had resonated down the belt matching it's frequency and loosening the bolt, it's just a theory but in my mind it seems a possibility and thus we will certainly be paying more attention to these two items in future servicing. Pete
blade7
Well-known member
Thanks for the info on the turbo, I was particularly interested as I have the same turbo in the garage. Re the A/C compressor I had one seize on a Volvo years ago and it broke the belt. When I fit the turbo I'll delete the A/C compressor, I think that changes the position of the alternator and gives some clearance around the bigger compressor inlet.
Hi Graham I would most certainly check it.... I liked the venom but am too wary to use another one...once bitten twice shy i guess.....my problem now is finding an air filter that is rated for more than 350bhp.... this seems much harder than one would expect..need to sort it soon as the clock is a ticking...turbo is confirmed for being back before the weekend and the Vitesse chip/board has been flashed and now just having a small repair after we damaged a pin when removing it..should be on it's way back to us before the weekend. Pete
small update.... throttle body... having read that the seals on these are unlikely to still be doing their job i decided it was best to renew all of the seals and I'm very happy that I did. first picture shows the new seal kit which includes new bolts, washers etc although there are one or two that you need to keep from the originals so be careful. You may notice the broken pieces of seal at the bottom... this is the remains of the 3 shaft seals and no they didn't fall apart during their removal, they were already in pieces, this is what 29 years of use in a hot environment does. Also the large 'O' ring that seals the joint between the TB and manifold has shrunk to a state that was useless as a seal, this TB had most certainly been leaking. One other thing to point out, the kit comes with two sets of shaft seals, one for street and one for track. The instructions point out that the track set gives the best seal but may cause a high idle due to the throttle not closing properly, it also points out that this is a temporary situation that sorts itself out after a few hours use to allow the seals to bed in. I chose the track set as i want the best seal possible, if the idle doesn't settle I can always make a stronger return spring... btw I noted that it's stated that the idle issue doesn't always happen...i'll report back how things turn out.
One final picture to show the TB back together ..the TPS has been put back as it was before but will be properly tested before starting the engine to ensure it's in it's correct position.
Pete
Evening all Another busy day with lots more progress..I'll try to list what's been done since last update steering pump and belt fitted and reservoir filled starter motor fitted, new cable fabricated and fitted to replace the 29 year old brittle original, also rerouted to keep it further away from heat. rebuilt alternator fitted and belt fitted , this also had new wires made up and rerouted. as an extra we also made up an earth lead from alternator to chassis rail. Turbo is fitted with turbo downpipe too. brake servo pipework fitted. rerouted engine breather pipe fitted to AOS which will pass behind brake servo as can be seen and then exit the car through the passengers side inner wing, using the same outlet that the fuel tank breather used before, an oil catchment tank will be fitted to the other side of the hole in the inner wing later. battery is fitted. in the picture the inlet manifold is only resting in place to check positioning for the various hoses beneath which have all been rerouted with old obsolete parts removed, much simpler now.
towards the end of the day and with all of the oil system connected and filled with mineral oil it was time to crank the engine over with the starter to see if we had oil pressure from the rebuilt oil pump. I'm happy to report that after about 50 secs the oil pressure began to rise fairly quickly until just under 5 bar where I then stopped turning over. That's pretty good pressure for just cranking the engine over at starter motor speed of around 150 rpm ? I guess the oil pump is doing it's job...it was certainly nice to have the engine cranking over for the first time in 4 years with not only very good oil pressure but also no problems whatsoever...fingers crossed it stays that way, we then fitted new plugs... tomorrow Richard will be around early and we plan to get everything else sorted ready for the chip's return... we are waiting for a 16mm banjo bolt to be delivered as the turbo builders had to re-thread one side of the water outlets due to a bad thread, looking at where this is we are confident that we can still get at it once the inlet manifold has been installed so it shouldn't hold us up. A good days progress if I say so myself.... Pete
PeteHi Pete, great looking build, look forward to the start up. With regard to the air filter I have a question,I am also looking around for one for higher hp but am limited for space due to fixed lights. Does the size really matter ? (I can hear the sniggering from here!) Surely the flow of air is limited by the size of inlet pipe opening and as long as the filter is free flowing it does not matter. If it does I will have to get creative with the inlet pipe routing. Simon
Hi Simon It's not as critical as some may think...I am referring to turbo engines when i say that you can get some serious power gains from other means even when still using the original filter/box as i'm sure some guys here can testify too. However it all helps, better pickup being one. Yes there is a balance between size and space and not forgetting that after market filters even when fitting into the original airbox are in general free'er flowing than OEM. I have been looking at the options today with my son... this leaves things open to a lot of experimentation, with that said we have decided to place the filter in the passenger wing through the original 4" hole in the inner wing, thus avoiding the hot air of the engine bay.. the filter will be a K&N cylindrical free flow type that iirc is 4.5" dia and 7" long, this will be connected to the MAF and then turbo with 3" pipework, should have quite a nice induction roar... Pete
Pete
today's achievements... Inlet manifold fitted dip stick fitted... during testing the breather pipework under pressure we discovered a leak coming from the dip stick where it enters the oil pan, this was corrected with a better 'O' ring. fuel rail fitted injectors fitted with new seals (55lb for running in) injector harness connected made a start on the vac lines HT leads connected ( forgot to say yesterday...new distributor cap, rotor arm and coil fitted) all fluids now filled....had a small coolant leak coming from the outlet pipe from waterpump to turbo..my fault I hadn't replaced the 'O' ring..lol other wise everything is bone dry. completed the hose work under the inlet manifold...deleted the venturi system turbo heat-shield fitted final job was to crank the engine over again to check we had compression...that we do and lovely she sounded too.....I am getting more confident that this engine is going to start immediately fuel gets through...can't wait....
regards Pete
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