The 215 and 340 were long out of production when HEI was introduced. I've got the Buick 350 hei on mine along with those injectors and it's nowhere near 20mpg. Even in the pre ethanol days 17 was hard to get, and that includes the ~15% increased odometer reading
Ignition coils
- Thread starter lunchbox
- Start date
Living in the area let me help - the roads although Interstate hwy are not flat to OBX. Maybe not the Rockies, yet, for sure hilly.
20 mpg in a RRC on that route is pretty good - I'm lucky if I get 12 with mine and yes, it is well maintained although not the stock engine.
However, the expense for gas is the least cost of RRC or D1 ownership imho.
The trip wasn't all on inter-states, and at 50mph. My wife and I crossed the Allegheny Mountains and into WV, and across the Appalachians into the Blue Ridge Mountains of VA. The road wasn't flat until we got into the Piedmont area and stopped at the in-laws in Stoval, NC. After the tour of the OBX, we set off for the Smokeys and Biltmore Estate, where we went to the Land Rover Experience site. So much for the 50mph on table flat roads, and we were loaded with vacation luggage, etc. My lead footed wife did most of the driving. So, use high voltage coils or not, doesn't matter much to me. Believe what I say or not, that doesn't matter either. I was asked how I got mileage to improve, so I did. How much of what I did wasn't necessary (?) Did I get the results I wanted, yes. Do I want tube doors on my D2, fuck no....
'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III V-8 Hybrid 109
'70 Rover 3500S
'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III V-8 Hybrid 109
'70 Rover 3500S
Fair enough. I'm not an expert in these engines, but I know enough to be skeptical of claims around significant performance improvements from 1970s era engineering technology. Being a west coaster who does a lot of driving in the mountains, my primary concern is keeping operating temperatures at safe levels.
70's technology could be improved - but not by upgrading individual components, but by change from carburettors and stand-alone electronic ignition to integrated EFI/ignition setup. Closed-loop fuel injection is a wonderful thing (which leaves you wanting the fat plunger of a 4-barrel carb's accelerator pump, but that's not gas-mileage friendly).
There's a lot less in 14CUX to be improved - and the improvement is called GEMS. Bosch really didn't bring much in terms of power or torque - but it made the engine run better while hot (which lessens the friction losses and, I guess, is good for gas mileage, even if it took the might of EPA to quantify that improvement).
At this point, there is little that could be gained with a single camshaft.
Isn't it remarkable that a AJ-8 can pump out more than twice the horsepower of RV8 with barely 20% more displacement? And deliver similar gas mileage (12 to 16 mpg) on a vehicle fully 20% heavier than an RRC/D1?
nothing remarkable about it. the 2004 rover v8 heads are almost identical to the 1960 215 heads. Throw 40 years of fluid and thermal analysis advancements in cylinder heads and intake manifold and I'm sure the short block rover v8 could keep up with at least any single cam pushrod engine still on the market.
There are several new technology engines in approximate range of the 4.2L Land Rover engine that get super gas mileage and aren't short on horse power. My two carbed engines (the '70 and '76) are both 3.5L Rover engines of the old school, and get about 15mpg on a good day. My old '69 AMC Javelin 290cid engine gets about the same mileage (and looks like an old Buick design, which it isn't...). All these have higher than stock horse power, but nothing to brag about in the Mpg department. And yes, they all have 40,000 volt coils (for better or for worse). You can only do so much with old 60'-70's technology, that's true. The reason I didn't mention the Buick 350 engine is that there were two, one a Buick and one actually a Chevy, and didn't want to cause confusion.
'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III V-8 Hybrid 109
'70 Rover 3500S
'99 Disco II
'95 R.R.C. Lwb (Gone...)
'76 Series III V-8 Hybrid 109
'70 Rover 3500S
Even those 290 heads are quite a bit more high tech with respect to pumping losses than the 215 heads. The later dog leg exhaust port design was even better, too bad the emissions era ruined the rest of the AMC combustion chamber.
and a Javelin with a 290? I thought they were all 390s and whatever the 360 was before the deck height increase.
Oh brother...
On what vehicle an AMC 290 will deliver 15 mpg? One with a stick shift or with a TH400 (that takes 45 horsepower just to keep going)? Likewise, a D1 with a stick shift can easily to 20mpg, while an automatic will take 5 out of it. Even with the automatic - you can easily gain or lose 2 mpg (relative to your usual driving style) by simply readjusting the kickdown cable.
I wonder where you are coming from. AMC V8 is not a Buick V8 (the front covers may look similar), and there is a world of difference between a Buick 350 with a Chevy 350.
Of course getting 200 hp out of a 4.2 V8 is pathetic - but there are very fundamental limitations. Even GEMS tends to run rich - because it is more difficult to reliably detect detonation in an aluminum block, so it is always easier to drown it in gas and retard the ignition. It is easier to get more power out of RV8 than it is make it fuel-efficient.
Robert - there was a 290 on Javelin, before 1970. I don't even know if they had dog-leg heads - their first year was 1970.
true, thats why I threw in that pushrod clause. And don't at least some those aj8s use a scroll variable length intake manifold?
if you step back to knuckle dragging domestic engines theres no reason a blank page design cylinder head and intake manifold couldn't give the rover v8 the same bsfc as a ls1. maybe the cam bore centerline to deck height could limit geometry with reasonable length valves, but I doubt it.
if you step back to knuckle dragging domestic engines theres no reason a blank page design cylinder head and intake manifold couldn't give the rover v8 the same bsfc as a ls1. maybe the cam bore centerline to deck height could limit geometry with reasonable length valves, but I doubt it.
I have no doubt that you can squeeze as much horsepower and as much torque out of RV8 as any other pushrod of the same volume. However... it won't be street-driveable, and surely it won't be fuel efficient. The beauty of it is not the power but the weight - nearly two hundred pounds under comparable iron small block. Makes little sense in a 4x4, but... that's what we've got.
I wonder where PM is coming from, I stated that although the AMC V-8's looked similar to the old Buick, it was not in any way a Buick design... The '67 through '69 AMC V-8's were the 290, 343 and 390, with rectangular exhaust ports. The next generation, starting in '70, were the 304, 360, 390 (last year for this in '70), and the 401 (starting in '71), and had the dogleg exhaust ports with better flow. The TH400 wasn't available until the end, and only on Jeeps. The early engines used B-W manuals and B-W automatics, later engines (I think it started in '71) used the B-W manuals and Torqueflite automatics. It's been many years since I drag raced AMC's, starting with a '69 AMX, '69 Javelin, '70 Rebel Machine, '74 Gremlin (of all things), and ending with a '83 Spirit AMX (converted to a '74 V-8 drive train). All with 40,00 volt coils... I know folks on here have a ton of experience with LR vehicles of all sorts, this is why it's a great source of information! But, I spent 34 years designing and re-designing all sorts of mechanical equipment. Have you ever wondered who had the first patent on the Energy Suspension style sway bar bushings, back in 1980? One guess... Oh, you didn't know Buick adopted the Chevy engine? That was after they had their own design 350...
Buick never "adopted" Chevy 350 - all of BOP(C) had no other option but use SBC.
I don't question your AMC knowledge - just get a chuckle on the high-voltage coil suggestion. It had _some_ reason to exist in the past - with poor mixture and oil control, high[er]-energy ignition could let you get away with dirtier plugs. But misfires on EFI engines are rare, even on 14CUX, and even more so - on GEMS. GEMS will throw a fit (and light up CEL) with not too many misfires; if one doesn't _live with_ a perpetual CEL and P1316 code, there's no reason for a high-voltage coil.
I don't question your AMC knowledge - just get a chuckle on the high-voltage coil suggestion. It had _some_ reason to exist in the past - with poor mixture and oil control, high[er]-energy ignition could let you get away with dirtier plugs. But misfires on EFI engines are rare, even on 14CUX, and even more so - on GEMS. GEMS will throw a fit (and light up CEL) with not too many misfires; if one doesn't _live with_ a perpetual CEL and P1316 code, there's no reason for a high-voltage coil.
Maybe I've just gotten in the habit of using upgraded coils, as I said I don't know what will happen on the D2 (nothing ventured nothing gained). As far as the BOP use of the Chevy 350, my using the word "adopted" was just a difference in semantics, I know why it was done. And that wasn't my point. And "Yes", Land Rovers are relatively new to me compared to the AMC's. The original question was, "What are decent coils for a decent price?" It went off the track from there.
Correct.
And here's my reasoning.
How can one coil, in the same formfactor as another, have higher output voltage?
Easy - fewer turns in the low-voltage winding, meaning more load on the driver feeding it.
There could be a half-way compromise, like a little fewer turns on the low side, a few more on the high side, but it would still load the driver more, and its output impedance (resistance and inductance) will be higher, meaning the current the coil is capable of producing is going to be about the same.
So... unless there is a clear indication of persistent or frequent misfires, one shouldn't be looking for substitutes. Especially on GEMS and later engines, for which there is no "high-performance" upgrade for the ECU's coil drivers.
Am I seeing the middle photo right - transistors not fastened to the heat sinks? Also, these aluminum ribs the transistors lean onto don't look like they could carry off heat if each of the transistors dissipated more than 2-3 watts with the underhood temp about 130-140F.
The transistors themselves were perfectly good for the job (http://www.mouser.com/ds/2/308/bu323z-d-293878.pdf) when the ECU was designed, even with predictably high saturation voltage at max current. But check it out (https://media.digikey.com/pdf/Data Sheets/Fairchild PDFs/FDPF12N35.pdf) - you may get yourself a very-much-upgraded GEMS coil driver!
Speaking of dwell - the factory coils may be low-impedance enough never to need dwell control.
The transistors themselves were perfectly good for the job (http://www.mouser.com/ds/2/308/bu323z-d-293878.pdf) when the ECU was designed, even with predictably high saturation voltage at max current. But check it out (https://media.digikey.com/pdf/Data Sheets/Fairchild PDFs/FDPF12N35.pdf) - you may get yourself a very-much-upgraded GEMS coil driver!
Speaking of dwell - the factory coils may be low-impedance enough never to need dwell control.