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MG MGB GT V8 Factory Originals Technical - DIS
Has anyone out there fitted a DIS to a Rover 3.5? I am considering an Electromotive HPV1 ignition control - amongst others. Naturally, I will need to install a crank sensor to do this, and the unit itself with four coils is quite bulky so I was considering mounting it where the distributor now sits.
Unfortunately I have just found out that the distributor drives the oil pump on these early engines, so can anyone tell me what is involved in updating the 3.5 to the more modern setup? Timing cover, pulleys, v-belt...?? How is the pump driven in the later models? Is this a huge task, is it easier to mount the unit elsewhere and just leave the distributor as is? Comments as usual appreciated! <VBG> :)
|Neil, how can you fit all that stuff in there?! ... things get _mighty_ tight in my V8 near where the crank trigger would go. Is this really all that much better or more accurate than just using, say, a Unilite distributor, some sort of ignition box and a decent coil?|
This is a huge topic and it's hard to get any real input from more than one or two people who have BTDT. Speaking to a qualified friend of mine who has BTDT but with different engines and systems, yes there is a significant difference in performance. Not like adding a big cam or anything but in a few more HP (compared to other systems), improved fuel consumption and improved idle. All good things.
But I know what you mean. Unilite is one way to go, or pertronix in my DP Mallory. Hook up a Mallory CDI or MSD CDI or Holley CDI perhaps.. but then in that $ range, you get to DIS, Direct Fire & multiple coils etc.
Comparisons I've read on the various systems seem to show that the Direct Fire type systems are the best. Now as to quantifiable performance improvements, no manufacturer quotes figures (how can they). I do know though that a Pertronix and a coil don't do much else except remove the hassle of the points, maybe give a bhp or two - so thats why I am considering other options and of course I love playing with cars and technology. I'm still at the research phase for all of this so will welcome some input!
I've decided I'm not interested in capacity upgrades on my car, so as far as getting more bang out of my 3.5 I've decided to go for optimising the ignition, carburation (drop my 500 to a 400) and probably a cam and PB ported heads a bit down the track.
As usual am open to hearing others opinions on why I am crazy. <VBG> All good fun. :)
Those not running stock points distributors - what are you running?
I am currently prepping a 4.6 to replace the Buick 215 in my converted V8. I've been running the 215 for 12 - 15 years w/400 cfm Carter AFB. The plan for the 4.6 calls for FI & DIS. I have a '99 Land Rover system (Bosch) which is useless for the conversion. I am looking at aftermarket units, primarily Accell DFI Gen VII which is due out soon. It is supposed to be much more reasonably priced than most others. I hope to use sequential injection.
The late engines w/DIS use a crank driven oil pump & timing cover with no provision for a distributor. There is an intermediate model timing cover w/ concentric oil pump and distributor bore. The late camshafts are shorter with no provision for a distributor drive gear & crank snout is longer to drive the oil pump. I am using an earlier (Crower) cam & Buick timing cover. I have on order (due in tomorrow) a Buick Grand National V6 cam sensor/oil pump drive (turbo V6 w/FI & DIS). This is essentially the bottom half of a distributor w/driven gear & pump drive. It will fit Buick oil pump gears, but not Rover. You would have to change to a Buick timing cover & oil pump. The timing cover is a direct replacement with the possible exception of the dowel pins which may need to be reamed. The cam sensor is about the size of a spray can lid & will provide the signal I would need for seq. FI. The cam sensor/oil pump drive cost about $150. at a GM performance center.
Hoping to get my block & heads back from the machinist soon. I will probably be ordering the FI in the next few weeks. I sure hope this works, but if not I can always fall back to the AFB & distributor. I will let you know how things turn out.
|Added my MSD breakerless distributor (same as Buick)and ignition control box (6AL) (and Magnetic tachometer adaptor) runs and idles well but now I must change the advance curve as it is running a little hotter (found this out after following a bus for about 2 miles in third gear) with the 28 degrees of advance added to my 10 degrees initial). I'll back it off to 25 degrees of advance. Quite easy to install and change the kit came with 3 different spring sets and 4 different cam stops. My V8 is a 1963 Oldsmobile 215 w/Carter 400 4bbl(internally stock so far) in a 78 B.|
|Michael S. Domanowski|
|When I was considering DIS, I was just going to strip down the distributor and leave it there. You can put the cap on it to make sure nothing hits the rotating shaft, but i'd just leave it off. |
You may want to see if Electromotive is going to offer a COP system (Coil on Plug). No More Wires!
If you do use a normal wasted spark DIS, get the coil packs in pairs and install them on either side of the car. That will be much easier than a 4 coil pack. I have a 3 coil pack in my pile of junk, they're not that big. Although i'm not sure if the electromotive system allows 2 separate packs.
This thread was discussed between 28/03/2001 and 03/04/2001
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