TDC on a Rover 4.6 V8

General Chat About Electrics, And Ignition Systems.

Moderator: phpBB2 - Administrators

User avatar
Rossco
Moderator Gold
Moderator Gold
Posts: 850
Joined: Sun Nov 19, 2006 11:33 am
Location: Too many to even keep count

Post by Rossco »

Another cheap way to do it is to use a plunger extension on a DTI



unstable load
Top Dog
Top Dog
Posts: 1278
Joined: Mon May 04, 2009 6:53 am

Post by unstable load »

garrycol wrote: I am using the highest Octane fuel I can get and I am not getting any knocking but if I have to start on starting fluid it does knock until running on petrol and on petrol there is no knocking even under load. So my thoughts are my marks are out.
I would think that starting on Start ya Bastard would almost certainly give you knocking.
Cheers,
John

garrycol
Knows His Stuff
Knows His Stuff
Posts: 527
Joined: Thu Jul 16, 2015 2:47 pm
Location: Australia

Post by garrycol »

DaveEFI wrote:If your TDC mark was out, then where you set the trigger wheel/sensor would also be out? As they are generally adjustable? If you are sure your TDC is correct, move the sensor in its slots to correct. If not enough adjustment, you'll have to move the trigger wheel. If it's like mine, both the trigger wheel and sensor bracket allow some adjustment.

So saying, my default EDIS setting is a couple of degrees out. I just trimmed this in the offset software setting.
Hi Dave - I have the trigger wheel and the sensor correctly lined up with the marks I put on the crank pulley - of course if that is not correct then the other components will be out. There is enough adjustment on both the trigger wheel and Vr sensor but if the pulley marks are out, the issue is what do I align them too.

As I indicated I did the process of determining the TDC position a number of times marking the pulley with chalk a number of times and the TDC spot was consistently the same so was happy until I put the timing light on which showed ignition with EDIS 8 was 14 BTDC not 10 BTDC.

From what little I know about tuning when I have MS3X connected it will not matter as it will just tune for best performance at each rev range and MS3X will just adjust ignition timing for best performance.

garrycol
Knows His Stuff
Knows His Stuff
Posts: 527
Joined: Thu Jul 16, 2015 2:47 pm
Location: Australia

Post by garrycol »

Rossco wrote:Another cheap way to do it is to use a plunger extension on a DTI
Thanks but can you translate that into plain english because I dont follow. :(

DEVONMAN
Top Dog
Top Dog
Posts: 1440
Joined: Sat Dec 13, 2008 2:46 pm
Location: Croydon UK

Post by DEVONMAN »

Quote (:-Hi Dave - I have the trigger wheel and the sensor correctly lined up with the marks I put on the crank pulley - of course if that is not correct then the other components will be out. There is enough adjustment on both the trigger wheel and Vr sensor but if the pulley marks are out, the issue is what do I align them too.) End Quote.

There is no need for the sensor and trigger wheel to coincide with the marks on the crank pulley. The TDC mark on the pulley (Which you seem happy with) can be anywhere on it's perimeter provided the pointer is pointing to it and you can beam a timing light easily at it.

As Dave has said, you just need to move the sensor relative to the trigger wheel, ie move the sensor slightly clockwise or the trigger wheel anti clockwise relative to the pulley when viewed from the front. Then check again for 10 degrees with the light.

By the way, there is no need to remove the rocker covers and view the valves as TDC is the same on firing stroke and exhaust stroke.
1950 A40 Devon Hotrod with 5.0 twin turbo RV8.
EDIS8 wasted spark, Holley Injection.
Been as far as the Moon and back in 57 years of driving. Same Car, 5 engine upgrades !!!


Image

garrycol
Knows His Stuff
Knows His Stuff
Posts: 527
Joined: Thu Jul 16, 2015 2:47 pm
Location: Australia

Post by garrycol »

Thanks - follow that but I am not now so sure my marks on the pulley are correct.

However Dave has answered my actual question about MS3X taking care of it anyway in the wasted spark thread.

http://www.v8forum.co.uk/forum/viewtopi ... 162#113162

In his last post he says
"To just check the trigger wheel/sensor relationship is correct. Once you've establishes that is fairly near, you can use the offset in software to bring it spot on."

So as long as it is near - as it is, as the engine runs really sweet even under load - the tuning software will pick up any difference. This saves me trying to revise the position of the trigger wheel, VR sensor and timing pointer as with my luck I am liable to stuff it up big time. :(

Cheers and thanks for all the responses.

Post Reply

Return to “Electrical & Ignition Area”