Johnmor
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posted on 10/11/20 at 04:09 PM |
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Rover 3.5 V8 , something not right!
Hi All
I have a 3.5 v8 fitted in my Viento, got the engine when i bought a part built kit for a local chap, the engine appears in good nick and he had
changed head gaskets and checked bore etc , said all is VG.
Set up the dizzy and got carbs sorted and fired it up, all very promising no major issues
My timing light had failed so had to get a new one, when i went to check the timing somethings a bit weird
Firstly to get the engine to run smooth on tick over i had to swivel the dizzy a fair bit (clockwise) , so much so that the vacuum diaphragm on the
dizzy was almost contacting the thermostat housing (for those that have a V8). seemed odd
When i checked with timing light against the marks on the front pullly the engine appears to run very smooth at around 14 degrees before TDC, and
picks up fine, that can’t be right surely. It just manages to tick over at 2 degrees before TDC (recommended setting) but won’t pick up and is lumpy
as hell so obviously not right.
Is there any way the front pulley could be on wrong and the timing marks are out, haven’t removed the pulley as yet , i assume its keyed on and
therefore cant be wrong,
Anything silly im missing here, seems to run fine but marks are way out !
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Mr Whippy
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posted on 10/11/20 at 04:28 PM |
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Could you not just have the distributor engaged one tooth out? and do you have the vacuum advance hose fitted when using the strobe as I thought it
had to be removed and blocked off. The pulley can't be fitted wrong unless there's no key fitted and I can't see the timing chain
having been fitted wrong as it so easy to see the marks on the sprockets.
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pmc_3
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posted on 10/11/20 at 04:40 PM |
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I'm not that clued up on the Rover V8's but I know in other engines it's possible to put the dizzy in 180 degrees out.
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Johnmor
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posted on 10/11/20 at 04:52 PM |
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Hi
Thanks for the reply
Could be the dizzy a tooth out ill check again, it drives the oil pump so its a little fidlay to get in right and connected properly, seems stange it
fired up first go so cant be a mile out
cheers
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Mr Whippy
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posted on 10/11/20 at 04:56 PM |
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yeah I've done that myself on a Pinto had that 180 degs out but on a V8 can you do that? not sure. That engine has 14 teeth on the distributor
drive so that's about 25 degs per tooth so seems too much if that was the problem. The fact that is can run smoothly does sound like something
is out though with the timing. Is the advance plate moving freely in the distributor? what about the ignition module, is it points or electronic, has
that been set right?
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Johnmor
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posted on 10/11/20 at 05:33 PM |
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Hi,
It's not 180 out, if it was it may run but certainly not a smooth as it is, 180 will back fire through the valves like a b***
It may be the dizzy being out, as you slide it down into the oil pump drive shaft it turns the dizzy shaft slightly, this may throw it out a tooth,
I'll check and keep trying
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gremlin1234
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posted on 10/11/20 at 05:37 PM |
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while I don't know the v8 engine very well...
I have heard of the woodruff key failing on the front pully of a triumph engine but its very unusual
you can check this by taking a spark plug out and rotating the engine till its tdc. and check the mark on the pully
oh and a dim and distant memory suggests the timing reference mark attached to the block might be bent! (check as above!)
but would strongly suspect as others have said, looks like this distributor drive is a tooth out (not 180 degree)
- this is a very easy mistake, since people forget the distributor internals rotate as it is fitted.
so with the engine set to tdc, and distributor at no1, it it will be in the wrong position after its gears mesh and it's slid into place.
for a pic of the drive cog, see
https://rimmerbros.com/Item--i-614033
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gremlin1234
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posted on 10/11/20 at 05:42 PM |
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quote: Originally posted by Mr Whippy
That engine has 14 teeth on the distributor drive so that's about 25 degs per tooth so seems too much if that was the problem.
but the distributor rotates at half the engine speed so about 13 degrees, which seems about right
edit, but perhaps that would make it 50 degrees, I shall go and think about it
[Edited on 10/11/20 by gremlin1234]
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steve m
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posted on 10/11/20 at 05:58 PM |
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I dont know the Rover setup, but certainly on my old crossflows, the timing marks were not in the exact position, and i cut a new one, when i
determined were TDC is, although i never used the light, just did the timing by ear
steve
Thats was probably spelt wrong, or had some grammer, that the "grammer police have to have a moan at
![](/images//smilies/bigsmile.gif) ![](/images//smilies/bigsmile.gif)
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Deckman001
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posted on 10/11/20 at 06:11 PM |
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quote: Originally posted by steve m
I dont know the Rover setup, but certainly on my old crossflows, the timing marks were not in the exact position, and i cut a new one, when i
determined were TDC is, although i never used the light, just did the timing by ear
steve
I might need to get you to have a listen to mine then if your that good
Jason
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Oddified
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posted on 10/11/20 at 08:01 PM |
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Quite often the dizzy vacuum unit can be virtually touching the thermostat, move it round 1 tooth if it is. The timing marks on the crank pulley are
notoriously inaccurate on the old rover v8's, check the the tdc mark actually is at tdc.
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40inches
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posted on 10/11/20 at 11:03 PM |
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Fitting a RV8 distributor seems to be a complex thing to do. Is this any help?
Fitting RV8 dis.
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Johnmor
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posted on 11/11/20 at 09:17 PM |
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Thanks for the replies,
Think I've got it, when inserting the dizzy it seems you need align TDC, align oil pump drive (10 to 4) and then align rotor arm to no1 cylinder
, then , and this is the important bit, rotate rotor arm anitclock wise 30 degrees to allow the helical drive gear to engage and bring back the 30
degrees.
All set , tickover sitting a 3degrees BTDC , with vacuume around 10 degrees BTDC
All sweet now
Thanks again
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Mr Whippy
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posted on 11/11/20 at 10:33 PM |
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Well done ![](/images//smilies/smile.gif)
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