Hybrid_From_Hell Posted November 7, 2012 Share Posted November 7, 2012 Hi All, Have been meaning to do this for a while, the 4.0 and 4.6 engines have no 'TDC' marks, which makes for a interesting problem in setting up the trigger wheel so have got me colouring set and crayons out again 1st you need to "Face Off" the rear of the Trigger wheel to a Flat just past the outer edges of the 2 x Mounting Holes Then you have to actually fit the wheel to the pulley and in the right place ! I have tried explaining this to peeps many times, but pics being worth a 1000 words and all that this may help You can also use a TDC indictator, Dial Gauge etc as well as this. This will at least get you in the right ball park, and then mildly tweak to spot on later Hope its of help and use If you want to do this and can't do the machining then for postage costs to and from you and a forum donation I'll do the machining for free in 2012(may review in 2013 ) Nige Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted November 13, 2012 Author Share Posted November 13, 2012 Now the Uploader for pics is working again have edited the thread and added the pics Nige Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted November 24, 2012 Share Posted November 24, 2012 Nige, If you were to produce a spark plug hole 'bung' the correct length, people can work out where TDC is much more accurately....? I made a rudimentary one by hollowing out a spark plug, but it was less than ideal Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted November 24, 2012 Author Share Posted November 24, 2012 Thats a fab Idea Hmmmm let me think on hw that could be made Ideas and back of faf packet drawings welcome ! Thanks Peter Nige Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted November 24, 2012 Share Posted November 24, 2012 Are all pistons the same on 9.35:1 RV8s? I used a DTI to help find TDC and im pretty sure that maximum piston height was achieved between 3* BTDC and 3* ATDC, this was the same as the pulley wheel marks on my 3.5 so we knew that the pulley was right, but on the 4.6 obvs you just find the centre point Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted November 24, 2012 Author Share Posted November 24, 2012 Sam No not all pistons are the same, plus if you have the deck machined / skimmed etc etc 4.0 and 4.6 crank pulleys have no marks on AT ALL Nige Quote Link to comment Share on other sites More sharing options...
Mr Noisy Posted November 24, 2012 Share Posted November 24, 2012 I still reckon DTI is the best option, but a spark plug threaded bolt would be easy also, I guess it would work for all engines be used you just find the centre point between the two marks either side of guesstimate TDC. Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted November 24, 2012 Share Posted November 24, 2012 A pencil stuffed in the bore through the spark plug hole works well. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted November 24, 2012 Share Posted November 24, 2012 I still reckon DTI is the best option, but a spark plug threaded bolt would be easy also, I guess it would work for all engines be used you just find the centre point between the two marks either side of guesstimate TDC. exactly Quote Link to comment Share on other sites More sharing options...
trulyalya Posted December 4, 2012 Share Posted December 4, 2012 Nige, just found a local workshop that would probably laser-cut the disk for me. The questions are what thickness should I choose, should it be stainless steel or 'usual' steel, what's the difference between the expensive and the budget one except for the flexible mounting holes, and what tooth shape should I prefer, the curved one like in your disks, or the straight one like presented in this dwg? http://www.megamanual.com/ms2/36-1.htm anyways the project is postponed at least till mid of january, when I finally get to the car... Quote Link to comment Share on other sites More sharing options...
alanius Posted January 3, 2013 Share Posted January 3, 2013 clicked to much, sorry! Quote Link to comment Share on other sites More sharing options...
alanius Posted January 3, 2013 Share Posted January 3, 2013 clicked to much, sorry! Quote Link to comment Share on other sites More sharing options...
alanius Posted January 3, 2013 Share Posted January 3, 2013 A pencil stuffed in the bore through the spark plug hole works well. But how do you know the valves will be closed? Thank you Nigel for this picture, needed this to set up the trigger wheel! As I find time to continue on the build of my engine :-( Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 4, 2013 Share Posted January 4, 2013 The questions are what thickness should I choose, should it be stainless steel or 'usual' steel, what's the difference between the expensive and the budget one except for the flexible mounting holes, and what tooth shape should I prefer, the curved one like in your disks, or the straight one like presented in this dwg? (most) Stainless is not magnetic, so not very useful for a variable reluctance sensor (Nige knows a story about this ), use steel. 4 or 5mm thick is OK, I think Nige uses slightly thicker, but he does that with everything! The pattern Nige uses for his wheels is IMHO a better one than the link you posted. Worth noting in all the discussions on alignment/TDC that the crank key is a rather useful reference point, if you align the wheel relative to the keyway in the pulley it will be correct. This is how I aligned mine when going from V-belt (RRC style) front-end to P38: Old trigger wheel: New trigger wheel: Maybe Nige could put a marker / notch on the wheel to indicate where the keyway should be and where the VR sensor should be? Quote Link to comment Share on other sites More sharing options...
teslo Posted January 9, 2013 Share Posted January 9, 2013 Just a thought...isn't woodruff key in same position as on v-belt crank and serp one? So if i just "copy" degree marks from v-belt crank pulley to serp one, will it be OK? I am going to switch engines from 3.9 pre-serp to 4.6 serp. Trigger wheel on my current 3.9 crank pulley is in almost ideal position (1-2 degrees out) so i planned to use it as a temlate to 4.6 crank pulley...thanks Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 9, 2013 Share Posted January 9, 2013 Yes: Worth noting in all the discussions on alignment/TDC that the crank key is a rather useful reference point, if you align the wheel relative to the keyway in the pulley it will be correct. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 9, 2013 Author Share Posted January 9, 2013 Few things MK 2 version that is the MK1 fridge has - MK2 now has adjustment slots see facebook Megasquirt V8 Page for pics second, the woodduff key is a "VERY APPROX" setting, you'll need to fine tune this (hence the wheel now having slots) and lastly, Rover V8s can have a range of TDCs dependant on tolerances, I have seen V8s where the TDC indicator, part of the Crank pully, is Waaaay out from true TDC ! Hence you need IMHO a "Rough" guide to the timing ssetup, and THEN the ability to easily get it then spot on ! Yes, I had a poncy customer who said my wheels were horrible, and would buy elsewhere , ok. Then some 6 months later he phoned me for help, bear in mind he bought nothing from me, but wnated help I spoke to him at some lengths, and what he described was basically no fire at all, and I quizzed him on the TW setting up, he was adamant he had it right, so I asked for a picture. Note he had also fallen out (or been told to Foxtrot Oscar from where he had bought everything from) and when the pics arrived yes timing looked correct I asked him if he has gone and had the TW Chrke plated ?, no, its high grade stainless................. Revenge is a dish best servered ice cold, humbly he then placed an order "so, just to check your order Sire, that an order for 1 x carp horrible TW that will maybe go rusty but at least will run your f engine replaceing your new coffee cup coaster to be, and 1 x portion of Humble Pie, with a helping of apologies and feet shuffling for desert, is there anything else you would like ?" In fairness he did then buy some brackets when I asked if the brackets on there where made by his local primary school (mine were too expensive, so he had a go bless with a Jigswa and some 3mm stainles was a F mess.....hey ho you can't help them all It started 1st turn of the key I didn't get a christmas card Neither did he from me Nige Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 9, 2013 Share Posted January 9, 2013 I'd have thought the key position was pretty much critical to getting the engine running right, as it would affect the cam timing otherwise? I hadn't thought of this when I did mine, even though I had a 3.9 block, timing cover, etc just sitting there Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted January 9, 2013 Share Posted January 9, 2013 I'd have thought the key position was pretty much critical to getting the engine running right, as it would affect the cam timing otherwise?I hadn't thought of this when I did mine, even though I had a 3.9 block, timing cover, etc just sitting there I suspect the TDC markers on the pulleys are a bit variable but the keyway itself should be pretty good, as you say, it's kinda important to the cam timing. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 9, 2013 Author Share Posted January 9, 2013 Le Mk2 Flavour Du 4.0 / 4.6 mit da Slotnez Nige Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted January 9, 2013 Share Posted January 9, 2013 I bet that's snug to the timing case on the bolt heads! Also, I remember when doing mine, there was only 1mm or so between the wheel and the water pump, those teeth look longer than mine, I'm assuming you have checked clearance? Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted January 9, 2013 Author Share Posted January 9, 2013 Snug as a snug thing, guess whats on the 5.2 It clears - F just Has 12.9T Flanged head bolts to keep inboard, a washer added too much !!!!!Nige Quote Link to comment Share on other sites More sharing options...
travm Posted August 4, 2014 Share Posted August 4, 2014 Might be a cheeky question but does anyone have a CAD drawing they can share of the rover 36-1 trigger wheel? Shipping of those things to downunder is horendous given the cost of the item and I can get one cut on the waterjet at school, if I had the dimensions... Quote Link to comment Share on other sites More sharing options...
Cheesy Posted August 4, 2014 Share Posted August 4, 2014 Might be a cheeky question but does anyone have a CAD drawing they can share of the rover 36-1 trigger wheel? Shipping of those things to downunder is horendous given the cost of the item and I can get one cut on the waterjet at school, if I had the dimensions... I do for the one I made but you might want to alter it a bit, if I was doing it again I would make the centre hole a tighter fit and not cut any holes to mount. Then clamp it to the pulley and drill through the pulley as with the ignition I have it doesnt really matter where the missing tooth is. I also dont know what the OD of the off the shelf ones are compared to mine, I ended up with approx 5mm square teeth and corresponding cut outs though. If your are at some sort of technical school or university it should only take 5 min to draw one up. pm me your email and I can send you what I used Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.