So the THOR type injectors are OK then by comparison to the GEMS type and don't need upgrading by comparison, if I read it right?
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So the THOR type injectors are OK then by comparison to the GEMS type and don't need upgrading by comparison, if I read it right?
Yep - bang on the money. The BMW influenced P38 has the better (German of course) injectors. Sleep easy tonight!!Quote:
Originally Posted by clubagreenie
Is there a thread on here that talks about the pros and cons of GEMS vs Thor/Motronic/Bosch without mentioning the war?
If I make the mistake of mentioning it I try to distract with a well timed Waldorf salad.
In terms of remapping etc then it sems you are better off with the GEMS set up as it allows a deal of tinkering. The Thor engine has been specifically designed by the BMW engineers to make it virtually impossible for the average person-bloke to tinker. There's an extensive explanation on a BMW 318 forum (same Motronic 5.2.1 setup) ...their beef was that there was minimal opportunity to tune the 318 engine for competition use... and you can only change it back and forth 12-14 changes (anymore than that and it becomes a "brick"!) see Motronic 5.2 Reprogramming
I did wonder about integrating a Thor engine to a GEMS ECU...but I'm not a systems integration engineer and so would not know where to start! They each have fuel injectors, a CPS, CKS, MAF, etc etc but use different numbers to 'talk'to the Traction control., auto transmission etc.I don't have the knowledge and a thousand hours or so of development time!
What Hoges said regarding the Bosch ECU. I also wanted to add, in terms of intake manifold geometry, Thor has a slightly larger throttle body (68mm instead of 65mm), and longer intake runners, which translates to better breathing (more torque available) at lower RPM at the expense of higher RPM performance.
With regard to replacement injectors, Rover uses an EV1 connector. Bosch Gen III (thin plastic body) are regarded as having a better spray pattern to Bosch Gen II (thick metal body), but both are much better than then Rover's Lucas disc type injector. A couple of comparisons below:
Lucas Vs Bosch Gen 3 Vs Bosch Gen 2 (yellowtop) Vs several others
[ame=http://www.youtube.com/watch?v=Emnax2J4FX4]comparison bosch 24 multec lucas bosch3 bosch yellowtop bosch22 - YouTube[/ame]
and a better comparison of Bosch Generation III vs Generation II spray patterns
[ame=http://www.youtube.com/watch?v=oxImoYMRUCA]comparison of Bosch 3 to Early design Bosch 2 - YouTube[/ame]
It would be worth mentioning that Bosch Generation 3 injectors do not have a provision for a circlip which secures the top of the injector to the fuel rail, however it really isn't needed. The fuel rail is rigid enough and secured to the intake manifold in such a way that the injectors are jammed between the two and have nowhere to go.
HTH
Bojan
I have to admit to being rather aroused by the sound of my new engine. Sexy as. Jeese I'm excited. Picking her up today. Just heard her running.
Now to break her in. Any recommendations? Oil change after 500km? Somebody said that towing a "house" up a hill at medium revs was a good way of achieving run in? So has anybody got a caravan they need relocating?
Be interesting to drive her. That's the weekend planned then. Get reacquainted. Will have to dig out the barry white. Must remember the tissues. Ooooh errrr misses phnarr phnarr :cool:
Good to hear mate!
I've always run engines in at low to mid revs and under load. The first engine I built for my Torana, I loaded the boot with bricks and went up the nearest mountain range. Third gear all the way up at about 2500rpm was enough load to really warm the engine and make it work!
The worst things you can do to an engine while bedding in are:
- Sit at idle for long periods of time
- Granny drive
- Drive like Peter Brock
- Sit at constant revs
My advice? Chuck a trailer with something heavy on the back and 'drive' it. Don't flog the life out of it, just make it work and get warm but not hot. And don't labour the engine at low revs. Keep the working rev range between 2000rpm and 2700rpm.
Cheers
Keithy
So initial impressions are good. Not cataclysmic results. Not that you'd expect that from a 2.5tonne vehicle. But definitely more sprightly and more get up and go. Torque'yer. If that's a word. Taking it easy so far. Sounds amazing. Just the noise alone restores the bank balance of the mind.
It'll be tight for a while. I guess further improvements will be felt gradually.
Will post a video clip a when I get chance. Just nice to have her home.
Looking back a few posts at the Gems v Thor debate. Trying to remember the maths but 65 to 68mm CIA with the extra length as well, a few things change. Sure there's the physical size but with that also an change in laminar flow area as well. There's a rough ratio for it I can't locate at the moment but for all.purposes and as long as the plenum volume was correct enough for each there'd be very little if any difference between them until you got over 6000rpm at least and started to run out of reserve gas volume in the system and it started to starve. Modifying the design of the plenum is first step then increases in size & length.
For our purposes (primarily torque & eco) stick to what it is. Else negative offset grind the crank. Use Honda (smaller) main bearings. Make/find new rods and pistons to suit new shorter stroke and reduced rod angle. gain ho andbrevs atvalexpense of economy and torque.