Crossflow starter upgrade

[Gridgway]

I tried to run the new uprated crossflow in my LA caterham this afternoon.  The starter motor isn't up to turning the engine over.  I don't think it's an earth problem as it's all back together with sparkly clean +ve and -ve wiring.  I tried adding a second battery and that made absolutely no difference.  The main battery is about a year old and both main and second batteries were charged.

I think I need to upgrade the starter.  It's an inertia type.  Any advice?  Choices I htink:

1 get the current starter looked at - although it worked fine with the 1600 that was there before.

2 get a high torque intertia starter if there is such a thing.  No rewiring required.

3 go to a pre-engaged type and do the wiring for it (which I think is simple).

Thanks

Graham

[Jonathan Kay]

What's the battery's (or batteries') voltage at rest and minimum during attempted cranking?

An advantage of refurbishing the existing starter is that both the connections and the mounting won't need any modification. 

Have you got all of the wiring diagrams that you need?

Jonathan

[Tazio]

My crossflow was fitted with quote' Hitachi Genuine High Performance Racing Starter Motor, inc adapter PSL 100' supplied by Sherwood Engines, works really well ! ( damn expensive though )

Alan

 

[Nigel Riches]

If you go for a pre-engaged type you will probably have to change the ring gear, 

[jbcollier]

If it worked before, it should work again.  Something is not hooked up correctly.

[Gridgway]

Thanks all

#4 why would the ring gear need changing?  And to what?

#5 I agree, but in this case I think it's unlikely with all new clean connections as there are so few.  The earth is definitely ok.  The only interruption to the live feed is the solenoid, so that could provide a high resistance, but I'd expect that to get hot with the current involved.  The engine is much higher compression which is the difference to before.

One of the diagnostic problems is that with the nasty vecta immobiliser you have to be in the driver's seat to crank it.  The meter needs to be connected remotely to measure volts at the starter.

I'll do some more diagnostics.

Yes I'm ok with the wiring thanks Jonathan.

[OldAndrewE]

Does it turn the engine over OK with the plugs out?

[Gridgway]

#7 very happily!

[rkeywood]

I'd look at the starter - a standard starter will be around 10Nm and should turn a motor with higher compression. I've still got an original 30 year old Lucas M35J type on mine which worked happily with 10.8 CR.

The main advantage of a gear reduction high torque starter is about 3kg weight saving. Inertia starters were 9 tooth pinion and 110 tooth ring gear. Pre-engaged were 10 tooth 135 ring gear. If you do want to swap then Edge (Burton stock these) and Powerlite both do 9 tooth direct replacements. Edge do 10T direct replacememts as well. 

Rob

 

[Gridgway]

Thanks Rob, that's very helpful.  I'll do some more investigation to check we are getting good cranking volts.

If I'm going to get the starter refurbed, I'll have to look for someone to do it.

There's also Wosp with a compatible starter too.

[rkeywood]

I've used Curd Bros in Tunbridge Wells for all sorts of refurbs which doesn't look too far from you. Proper old school guys who rebuilt in the workshop with some great old machines.

[Gridgway]

Thanks again.

Now a strange turn up this afternoon.  I rechecked the earth.  0 ohms as far as my meter can tell.

Then I rigged up a fly lead to activate the solenoid direct from the battery without 12v to the starter to measure that resistance.  Again no ohms.  All good 

Then I thought I'd measure the cranking voltage with it properly connected minus fuel pump and 12v to the coil.

Lo and behold cranked like crazy.  No problem at all.  I was wondering whether the solenoid was sticky and 12v direct from the battery freed it up.  Clutching at straws now though. 

The starter is clearly fine.  I'll monitor and see if we have other issues.

Just got the wings to put on then we'll be ready for the rolling road to run in and set the carbs up.

Overall I'm dead chuffed.  I plumbed and wired in an electric fuel pump with a solid fuel line, new ignition system and wiring.

Apart from the starter problem it has been flawless.  No leaks, no stray sparks (hehe), no blown fuse and the rebuilt engine runs now.

Thanks again for the help!

Graham

[Nigel Riches]

Hi Graham.

The other difference, apart from as posted by Rob (# 8) is the lead in to the teeth, inertia type spin the pinion into the ring gear from the front, pre engaged pull the pinion from the rear, and then start cranking, thus the tooth lead angle needs to be on the correct side, and also the correct number of teeth on both.

But it seems you are making progress, so bash on, sounds like the starter is OK, good luck.

Cheers.

Nigel.

[Jonathan Kay]

Graham

What do you now think was the problem when it wouldn't crank?

Thanks

Jonathan

[Gridgway]

That's a very good question Jonathan.  It's not obvious.  I didn't actually change anything.  In the course of investigatging, I I took off both battery connections and put them back on.  I had previously cleaned and abraded the battery posts and clamps, so that's not likely to have made any difference.  I also fired the solenoid from a fly lead direct to the battery rather than through the ignition.  I did this without power to the starter so it didn't crank.  It made a big clunk which made think it might have been a bit stuck, but that's not very likely that the solenoid worked a bit yesterday, but not fully and reduced the cranking current.

The battery was on charge overnight, but the day before I used two batteries and it wouldn't crank.  I did use the main battery to crank without plugs to get the OP up.  Then I connected the second battery using jump leads to try for the actual start.  May be by that time the main battery was down a bit and I failed to connect the second battery somehow with the jump leads.

We'll see if it works next time I come to start it!

[Jonathan Kay]

I'm glad it's not just me!  : - )

Have you inspected and cleaned the relevant earth connections as well as the feeds?

Does it have a starter relay?

Jonathan

[Gridgway]

The starter relay is the seperate solenoid for the inertia starter and the 12v feed to activatethat is not on a relay as it is a relay.

The earth was off for the build and it is all sparkly and clean, goes straight from the battery -ve to the bellhousing.

[Gridgway]

I have been chatting with a friend of mine who is far more knowledgeable than me and I regaled him with my tale.

He pointed out that a problem may be with the advance of the ignition.  It was set by the engine builder as a starting point prior to fine setup on a rolling road.

Now to the test I did on Sunday.  As I was just cranking without fuel and spark, there would have been no ignitions.  I strongly suspect that if I do the same test again with fuel and sparks trying to start the engine, I'll get the problem back again.

I'll need to work out how to do static timing.  It's a long time since I've done that.  He suggested if the problem is there, I set it to a smidge before TDC and see what happens.  Then we can get it properly set on the RR and see if we still have the problem. 

 

[rkeywood]

To see where the timing is now put a test lamp between the distributor LT connection and earth. Rotate the engine with a spanner on the crank bolt (plugs removed, ignition on) until No 1 piston is rising on compression stroke (rotor arm opposite No1 pin). When the light just comes on see where the notch on the crank pulley is against the timing marks on the front cover. If it's close to 10 deg then I'm guessing the problem is elsewhere. If it's well over 10 then continue to rotate the crank to 10, slacken off the distributor clamp, back the distributor off anti-clockwise, then rotate it clockwise until the light just comes on and reclamp.

Rob

[7_Tea_7]

Just had my old Lucas SM from my 94 spec xflow refurbed at:- 

https://www.burghfieldstarterandalternatorcentre.co.uk/

What an amazing difference it made. Can't recommend this place enough, proper old school. All working smoothly. 

Always best to catch a sick Startermotor early before it does too muck damage.

 

Thinking now in fixing electric ignition,  just to put the cherry on top of it.

 

[Gridgway]

Super thanks for the recommendation.  I'm expecting to need to return it to get it working a in top form.

Mind you, it can't be beyond home skills to take apart, clean and replace brushes and stuff!

 

[Golf Juliet Tango]

I have similar experience with reconditioning from "Unit Exchange" in Borehamwood. 

https://www.unitexchange.com/

There are few of these traditional repair shops about. Sadly cheaper manufacturing has lead to substantial waste creation in a throwaway society.   

(These cheap non-OEM units are, in my experience, less reliable.)

 

[Gridgway]

Thanks for another recommendation.

It's not the easiest of things to wrap and ship, but I'll get it off and to someone.  I'm not going to have time over the next few weeks to do a DIY job.  And in fact I have got my new BDR resto project coming on Saturday, which was reported to have a lazy start when it was last used in 2008!  So I'll get them both done.

[Gridgway]

Quick update here.  I have had the Lucas LRS 100 starter motor tested (along with the same model from my next 7 project) and both pronounced to be in fine health.  I re-checked and recleaned all the connections.  Tried both starter motors to no real success.

I then had the battery tested (2021 one from Halfords) which easily exceeded the rated CCA and was pronounced in fine health.

Then I experimented with reducing the ignition advance by rotating the dizzy.  It was too advanced and I had a bit more success.  It would successfuly crank about 1 time in 5, better than nothing.

But with nothing else left to try, I have bitten the bullet and ordered a new hitorque starter motor,  The starter motor man at Burghfield (who is excellent I have to say) assures me that being a pre-engaged type, the run in on the starter motor teeth will do the job just fine without having to do any ring-gear changing.  All 4 race cars I have with ford engines happily run pre-engaged starter motors without changes to the ring gear, so here's hoping that a/ it'll be ok and b/ solve the cranking problem.

Hopefully find time to pop it on over the weekend and even more hopefully give the final update!

Anyone want a Lucas LRS 100 starter motor tested by the starter motor man?

[Jonathan Kay]

"I have had the Lucas LRS 100 starter motor tested (along with the same model from my next 7 project) and both pronounced to be in fine health.  I re-checked and recleaned all the connections.  Tried both starter motors to no real success."

"Then I experimented with reducing the ignition advance by rotating the dizzy.  It was too advanced and I had a bit more success.  It would successfuly crank about 1 time in 5, better than nothing."

Did he test it with the same solenoid that you're using?

What happened on the other occasions when tested in the Seven... any noise, any turning, and what was the effect on the battery voltage?

Thanks

Jonathan