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Don, It's not the transmission, it's the car. Whenever I have driven hiway 80 in my 72 with the 5 speed, I still have people in big cras crowding me. But yeah, I guess it is better at 75MPH. In slow traffic I one had some asshole pass me in my lane since I didn't take up the whole lane! Gerard "gerardchateau" 25213... MORE
Well said, Don May... You hit the nail on the head..exactly spot on. This is the position I found myself in, more or less. Prior to knowing about the Datsun 5 speed, I attacked "the problem" by moving the whole rpm range upscale to 7-7.5k rpm by "Vizarding" a 1275 and making 4-4.5k rpm a comfortable cruising rpm. Supertuning the motor to take higher rpm is not inexpensive... for it's operating range is just short of a track motor. Weber 45DCOE, bigger valves, prepared head, VP3 cam and 1.5 rollers, big bore LCB and large diameter free-flow exhaust system... MORE
All the discussion on transmission and differential changes have forced me to face some harsh realities . . . Where I live in order to get out of town there are only two choices; Freeway or miles of traffic clogged streets. Freeway speeds here outside of work hour traffic and accidents seldom flows less than 65 miles per hour and 70 to 75 miles per hour is the normal traffic flow speed any speed less than 60 and you create a dangerous traffic slow down and hazards as people pass you on any side there is an opening. Makes... MORE
"What's the sense of gearing these cars primarily for highway cruising?" Well.... 'Cause I didn't get a BE so I could leave it home in nice weather when I commuted down to NYC airports to fly the friendly skies in bascially 70mph limited access highway driving circumstances where having a 5 speed enables me to tune for low and mid-range instead of top end, as one might have to do with a 4 speed and 3.9. :):) All depends upon the driving circumstance, state of tune, spec., etc. Considering my engine spec in terms of torquey low and mid-range... MORE
Yes an excellent motor sport diff used it all last year however it is very busy on the road and a bit short on long straights and to get the best you need a free reving engine etc mine is safe to 7500 and revs freely to 7000. Some other competitors are using 5.3 very rare now only fitted to Morris Minor GPO vans I think "Peter Whittle" 25187... MORE
Don... "Sounds" (excuse the pun:) like you've got a glasspack (free flow) on there, maybe a Thrush or Cherry Bomb. These are "straight thru" designs (as opposed to the "baffled" stock (or Midas/Meineke/ Walker, etc.) system. It may also be the optional "GEX" straight-through type I've see advertised by MiniMania. "Straight thru" design with sound deadening packed around the "open" core allows for perfomance and/or gas economy along with allowing for a cooler running engine due to the easier trip the hot exhaust gases have outbound. allow the engine to run a little cooler as well as the exhaust... MORE
The useless road engine was the cars original 948 motor.. that was a right screamer, and overheated in traffic all the time.. The Current one seems much happier, but as I said the result is it will not even notice going right round the rev counter and out the other side in 4th!. The modded 1275 does have a lumpy idle, but pulls cleanly from standstill, and can pull off from rest in 4th although this does require abuse of the clutch (but not as bad as you might think.) I believe my 1500 has a 3.9 diff so... MORE
it's simply down to the noise suppression capacitor inside, its does not like being connected back to front!, connect it up backwards and you can reverse the polarity. Stewart "Ford Prefect" 25169... MORE
You can anticipate the changes by working it out in terms of percentages. Changing a 4.22 diff with a 3.9 diff is about a16% change. Revs in any gear for a particular road speed will reduce by 16%. Or road speed will increase by 16% for the same revs. In theory (but not in practice) acceleration will be worse by 16% which sounds a lot but is barely noticable. That said, acceleration changes are not quite so straightforward as it depends on how well the gearing is matched to your particular engine torque and power characteristics. And these depend... MORE
Stewart..... If your engine is tuned for the high end (and it certainly sounds this way.."useless road engine"...."lumpy idle"), then going to a 3.7 will make it more a useless road engine in terms of the low end. So...it you are using the car mostly at highway speeds (say, 3k or higher) than no problem. Town driving will become more of a hassle as you'll be at lower rpm more of the time at lower speeds, unless you retain lower gears more of the time then you are currently used to. The more available 3.9 might make for a... MORE
You've successfully made every argument on the situation. Pick your poison...'-) The OD unit is probably the easiest and most practical. Your other option is to install a 1275 with a Datsun 5 speed. That's the best choice in my opinion. Easily done too. You could opt for all Datsun drive train too. Gerard "gerardchateau" 25154... MORE
I have a 3.9 matched with my 5 speed and personally I would not not the low end results with a 3.7. Some do like that combo, but what the sense of gearing these cars primarily for highway cruising? Might as weel drive the Volvo. Gerard "gerardchateau" 25151... MORE
Stewart, is the 1275 in standard tune? If so, the acceleration won't be sparkling but it's perfectly usable and much more relaxed than your original (which would have been 4.22:1 not 4.55) The top gear mph/1000rpm will go up from around 15 to 18, so 70mph will see the revs drop from 4700 to 3900 (roughly) Don't forget though, that BMC could get away with making 1275 Spridgets with 4.22 diffs as standard, so they must've thought it was reasonable at the time! Regards David "David Jacobs" 25148... MORE
IIRC the fraction you refer to is in fact the number of teeth on the pinion/crown. Actually I was gong to ask about diffs any way. I have two for the frogeye (which has a later 1275 motor) the original one which IIRC is 4.55:1 and a riley 1.5 one which is a 3.7:1 diff. What would the effect of fitting the 3.7 diff to the frogeye have, as it stands its will rev straight through the red line and out the other side in top gear, even up hills speed at the red line is 80 ish with... MORE
Nigel, it's good if you want storming acceleration for sprinting/hillclimbs etc, but you'll run out of revs at about 85mph. Looking at http://members.fortunecity.com/minormania/html/article_restore_axles.html says yours came from an A55 van, which I would have thought had a B series diff, so I suspect they mean A35 van, but I may be wrong here. Regards David "David Jacobs" 25137... MORE
Nigel, Hmmm. 8/39, that would make it a 4.875:1 ratio and a new one on me. I see from the link David J. provided there really is such a thing. As David says, quick acceleration but soon high rev's. Stock Bugeyes and early Spridgets were 4:22, later Spridgets (post 68) were 3.9 and the last Midgets were 3.7. 4.55's were used in Morris Minors and loved by racers. Gerard "gerardchateau" 25140... MORE
Hi guys I was given a couple of Spridget differentials recently, but I can't seem to figure out what ratio's they are. Does anyone know if there are any identifying marks on diff's to indicate what ratio they are? Thanks in advance. Nigel "amukdigiphoto" 25126... MORE
Should be OK though you'll probably only get one wheel turning and just hope it doesn't fall of the jack when you are doing 6500 revs in top. Also some possible issues with lubrication if you are jacked at an extremme angle for too long. "Jeremy Cogman" 25122... MORE
Don't know. The car was not driven for almost a year and I do not know what all the PO did to it. The guy I bought it from bought it running, drove it home and a couple of times around the block, did some work on the battery pan, put in a new radiator and hoses then got too busy at his job to do more so never took it off the no-op license and let it sit for almost a year, then when he tried to drive before selling it discovered he could not get it into... MORE
Not correct according to my source. This information is from the Chilton's Nissan 210/1200 repair manual. 1974 B210 Sedan and Coupe- A13 1975 B210 Sedan and Coupe- A14 1976-78 B210- A14 1979-81 210, 210 MPG -A15 The book goes on to discuss A series into 1982 models, but the question was about A series engines. A-series engine were used in the 210, B210 and 1200 Nissans. beginning from 1973. These include A12, A12A, A13, A14, A15. The A12 is considerered to be very disirable because it is the least choked and detuned due to SMOG restrictions and it has... MORE
Went to the DMV and took my Purple 73 rwa off non-op today then took it out for its first freeway speed run. Was hoping a good run would cure my transmission problem I posted about before . . . can start it in first and reverse and runs fine in first and reverse, however once I drive and shift up to second and above then stop I cannot get it back into first or reverse . . . gears grind (yes, I do shift into second first, then try first) I do not want to force for fear... MORE
spent a maddening day working on the car...... my dizzy is in terms junk, something is down inside that is making horrible noises. I went to plan b and installed the spare, she works great. with points! I tried to install the petrtonix I bought yesterday and have no spark. I went back and put the points in, and its great, have been on the phone all day with tech at petronix and im no closer than before. Just got back from the store where I witnessed some child abuse in the parking lot. Lady was hurrying her 2... MORE
I'm still trying to put a Datsun/Nissan A14 engine/5spd tranny in a 71 Midget. I have seen pictures of one in a 76 or 77. It looks like it comes from the factory. The Datsun engine seems to be an almost direct copy of the Spitfire engine, but with improvements: 5 main bearings, good oil seals front and rear thrust bearings integral with main bearing(it won't fall out!), aluminum head with great intake ports, etc. The 5 spd tranny is butter smooth and quiet. May not get you the horsepower a RX7 will get but it can produce 100+... MORE
if he does, you could turn the engine 90 degrees, and then run a drive belt from the engine to the skateboard wheels - think of the power to weight ratio! "David Jacobs" 25074... MORE
Interesting experiments, Paul. The most simple well-working PCV system I ever had came on the '67 engine 5 main bearing engine which I installed in place of the 3 main bearng which came in my PO'd '64 MGB. Factory PCV valve (rubber diaphragm) intake manifold mounted breathing through the liquid/vapor flame arrestor mounted on the front of the timing case cover with matched vented/filtered oil filler cap. Replaced the diaphragm once and filtered cap once in a while. And introducing a little water into the intake manifold once a year will help keep things clean. There are also a... MORE
