Oilburner
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| posted on 1/3/05 at 12:53 PM |
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Engine - Gearbox - axle alignment
Hi all
Just got to positioning my engine and box in the chassis frame (1600 xflow), a la book chassis on 1"packers, when I look at the gearbox output
splines and the diff pinion the appears to be about 3" height difference, is this right??
I know that the output shaft and diff pinion should not be directly in line but is this offset correct?
Any pics would be good.
Thanks Oilburner
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clbarclay
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| posted on 1/3/05 at 01:12 PM |
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3" over several feet (about 3 or 4) soudn't make a difference, more of a concern is the fact that gearbox out put is angled down. thats
ideal in an escort etc. where the engine is mounted much higher but not so good on a locost.
I to am at this stage (just finishing of mounts for engine /gearbox) and wondering what difference the angle of gearbox makes and wheather the diff
input need sangling up to compensate?
If your wondering why the engine/gearbox is angled down it is so that the standard carb is near vertical, the way it should be.
[Edited on 1/3/05 by clbarclay]
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white130d
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| posted on 1/3/05 at 01:45 PM |
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engine angles
FAIK, both the output of the transmission and the diff need to angled a little, if not then the u joints won't lubricate properly. Of course if
you get too much angle then you can put them (the u joints) in a bind and snap them. But I have only seen that in 4x4's with to much lift and
high pinion angles.
David.
"There's only 2 things that money can't buy, and that's true love and home grown tomatos" Guy Clark
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clbarclay
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| posted on 1/3/05 at 02:18 PM |
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About gearbox angle, how much of a difference does it make it front UJ is running at a differen angle to the rear UJ (semetrical) does the varying
velocity have any noticable effect?
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Oilburner
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| posted on 1/3/05 at 02:35 PM |
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Thanks for the replies.
Should have mentioned that the axis of the crankshaft - gearbox output shaft is parallel to the chassis bottom rails, and that the diff mounting has
been set up to give 5" ride height at the rear, with the trailing arms parallel at this ride height.
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britishtrident
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| posted on 1/3/05 at 03:11 PM |
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Westfield mounted the xflo with the crank centre line 120mm above the bottom of the chassis.
Agree about slight offset between diif and gearbox but the angles should be equal to avoid vibration -- I had experience of some early rwd cars
with IRS that had propshaft UJ problems because the gerabox exactly lined up with the diff pinnion.
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clbarclay
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| posted on 1/3/05 at 03:32 PM |
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Oilburner, I pressume from gearbox being level that either your using side draft or the carb is not mounted at an angle unlike a 1300 with 2v
webber.
If any one knows the answer to my earlier posts about gearbox sloping down then do say.
Should I remount the engine/ gearbox so that crank shaft is level rahter than carb?
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Oilburner
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| posted on 1/3/05 at 04:57 PM |
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I have aligned the engine/gearbox to be parallel to the chassis both longitudenally and transversly.
Initailly proposing to use the standard downdraught Weber however, I must admit that I hadn't thought that the carb may not be level with the
engine in this position (float chamber function etc) must check that tonight, although I guess some variation is acceptable.
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MikeP
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| posted on 1/3/05 at 05:02 PM |
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Boyd Coddington in his book "How to Build a Hot Rod Chassis" says that it doesn't matter if there's a height difference
between the tranny output and diff input. The important thing is to set them up parallel to each other. You need to make sure that the resulting
angle to the driveshaft u-joints is within the maximum allowed working angle - 12-15 degrees IIRC, perhaps someone else knows for sure.
Once you've got the outputs parallel, some rod builders suggest to offset one side about 3 degrees to promote even wear of the u-joints, but he
notes that not everyone believes this. Probably depends on how many miles you're planning to put on it.
Never played with it myself (other than in my unfinished build), but I've heard Boyd's advice echoed by other experienced locost builders.
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RogerM
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| posted on 1/3/05 at 06:07 PM |
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The front of a X-flow engine needs to be heigher than the rear to help promote a thermo cycle in the cooling system. If you don't have block
slightly inclined you will end up with problems cooling the cylinder head at the drive end.
As for transmission angles, so long as not excessive it's fine. With a fixed diff (IRS / DeDion) it is impportant to have a slight angle in to
circulate lube in the joints, with a live axle there will be enough movement during normal running to premote this.
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Oilburner
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| posted on 2/3/05 at 12:25 PM |
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All
Thanks for the info
Oilburner
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tks
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| posted on 2/3/05 at 01:05 PM |
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what if you pass the angle???
i dunno if i do...
but like i do..
what happens if you pass the angle??
TKS
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