why would there be more power lost through a heavy box as against a light box!
rob_man,
Jan 14, 6:18pm
Gearboxes and diffs gobble horsepower, if you go too heavy with either there will be a significant power loss. The trend lately has been to run the lightest possible driveline in racecars, or so I'm told. A 1600 X flow will make fairly good horsepower but doesn't have the torque to break drivelines like a bigger motor.
pfemstn,
Jan 14, 6:43pm
sierra box does not bolt straight up to a 1600 bellhousihg! but,imput shaft is longer so you can adapt easy with a spacer!reading all the above i would be tempted to ditch the Ford engine and do a jappo repower. something a bit lighter and more powerful!
bill-robinson,
Jan 14, 6:49pm
I think you are mixing up weight (pounds, kilograms ) with friction
rob_man,
Jan 14, 8:47pm
No I'm not, the bigger the box the greater the loss of power through the driveline. If you think otherwise picture a small engine driving a Road Range box, extreme example maybe but you get the picture. I know of one Ford that gained a full second over the quarter mile from changing from a C6 to a C4.
bill-robinson,
Jan 14, 9:04pm
really! I agree with you on the diffs9 inch diffs have about 20% loss sorry, no connection to original post.
NZTools,
Jan 14, 11:04pm
Basic maths. 3.1:1 is a lower ratio than 4.1:1 a lower ratio between the output shaft of the gearbox and theroad wheels will give taller (faster) gearing,
Ie low ratio= higher top speed. Higher ratio = faster acceleration, and slower top speed.
rob_man,
Jan 14, 11:19pm
You would be in a group of about 1% who think that. Think lower gears in the gearbox as opposed to the higher gears. If you want to get all pedantic about it the term should be "lower geared" not "lower ratio" but it's the generally accepted way of describing it. Even using the term ratio can still work if you think about engine revs versus wheel revs the other way around.
elect70,
Jan 14, 11:58pm
There was a guy called Brian Ax that raced aA40 Farina while back,asaclassicbut never got to see what he had in it,certainly wasnt standardBMC
rob_man,
Jan 15, 1:32am
Maybe an MGB 1800 ! There was at least one racing in that form.
mgmad,
Jan 15, 6:45am
Brian Ax's car ran an A series with a cross flow head and triple webers. I don't know what 'box he ran but almost certainly not the standard one, as they weren't known for their longevity in a standard car, but Toyota starlet conversions were relatively popular behind the A series.
xs1100,
Jan 15, 8:33am
the 1500 was a non crossflow popular converstion for the old 105 e anglias
4piggy,
Jan 15, 9:02am
did 1 a few weeks ago in a mk2 used a 1600 sierra clutch kit(spline different than cortina), had to convert to clutch cable to suit box, shorten driveshaft and fit different yoke(serria had donut), longer speedo cable, mount and lever back approx 2 inches, moved exhaust to clear cross member, and used cortina mark2 starter , length of shaft and bolt pattern on gearbox the same as standard, made a huge difference and well worth doing
skull,
Jan 15, 9:02am
Thank you.
If the motor is "screaming" at a relatively low speed in 4th gear (which is 1 to 1) then op will get more benefit from sorting out the diff gearing than he will from an extra gear in the gearbox plus all the extra work that fitting another gearbox will involve. If it's screaming in top you can pretty much guarantee all the other gears are lower than necessary as well. I still think that a diff housing from Anglia, Escort, Cortina, Capri would be a better bet. One of them will be pretty close in width to the Farina diff and you can choose any of the drum brake sizes of the above models if you want better than Farina brakes at the back end. There are a huge range of crownwheel and pinion ratios for those ford diffs. I seem to remember back in the day getting a 3.5 to 1 to put in my Zephyr powered 100E Prefect, it was still a bit low geared even with that one.
snoopy221,
Jan 15, 9:10am
Just to CLARIFY. Ya talkin 3(THREE) TWIN THROAT CARBS ON A 4 CYL!
[As in *splits*-or a 6 cyl!-or TWIN CARBS!]
mgmad,
Jan 15, 10:04am
As in three twin throat carbs.
Although, to be fair, only two were feeding the engine. It was running a Derrington-style 7 port head, so the original exhaust manifold could be used, and therefore a "standard" weber manifold would fit. Used to confuse the hell out of people.
jayrs2000,
Jan 17, 12:23am
hey just wondering if anyone is looking for a 1978 mk2 4 door! Photos in my listing thanks
hatchback,
Jan 17, 1:06am
The Datsun idea is a good one, nice and light, basic, lots of bits to pep them up abit OR what about series 2 V6 Commie and auto
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