RV8 Camshaft sensor

adamnreeves · Post by **adamnreeves** » Fri Jan 06, 2012 10:38 am

I have upgraded my ECU from MS2 to MS3. One of the follow on little projects is to go full sequential injection. For this I need a camshaft position sensor. Now I have the Intermediate timing cover with the cam sensor boss casted in which will require drilling out. Obviously I do not have dizzy but coil packs so have no dizzy drive on the camshaft. The camshaft is the later one which has a retainer plate.

What options do I have. Any pictures would be useful. Thanks.

stevieturbo · Post by **stevieturbo** » Fri Jan 06, 2012 9:19 pm

Surely if there is a boss already there for a sensor, then there is a tooth of some description on either the camshaft, or cam gear that you can use ?

or adapt in some way ?

adamnreeves · Post by **adamnreeves** » Fri Jan 06, 2012 11:06 pm

stevieturbo wrote:Surely if there is a boss already there for a sensor, then there is a tooth of some description on either the camshaft, or cam gear that you can use ?

or adapt in some way ?

Well the block is a GEMs X-bolted block.
The timing cover is a intermediate cover off a 3.9EFI

I dig out a picture of the front of the engine after I installed the camshaft:

Picture of my timing cover before installed:

I reckon that will position the sensor to read the cogs off the camshaft timing gear which is fantastic. Can someone confirm.

stevieturbo · Post by **stevieturbo** » Fri Jan 06, 2012 11:15 pm

Mmmm could ya make it any bigger ? lol

I'm assuming the trigger is the cam wheel itself ? Although not sure how it decodes a signal from that ?
One metal section is smaller though. I guess that could be sufficient somehow.

adamnreeves · Post by **adamnreeves** » Fri Jan 06, 2012 11:31 pm

stevieturbo wrote:Mmmm could ya make it any bigger ? lol

I'm assuming the trigger is the cam wheel itself ? Although not sure how it decodes a signal from that ?
One metal section is smaller though. I guess that could be sufficient somehow.

I did it big to see the cogs. Re-sized it now.

This exploded view of a Gems engine shows do other trigger wheel so it must read the teeth I guess.

stevieturbo · Post by **stevieturbo** » Fri Jan 06, 2012 11:40 pm

What is the cam gear made from ?

You'll probably need to create a single tooth somehow for the sensor to see as it passes.

Although it could need to be quite tall so the air gaps and cam wheel dont interfere with the tooth. And just space the sensor off a bit ?

adamnreeves · Post by **adamnreeves** » Sat Jan 07, 2012 12:01 am

Hear what you saying steve, i.e. need to know the camshaft angle in order to establish if on the induct or exhaust stroke. But I cannot help wondering how the RV8 solution determines this, unless it takes a 50-50 chance but then they would be no need for the sensor then I guess! Cam gear is ferrous metal, probably steel.

Quote from V8 Wizzard:
"4.0, 4.6 litre Sagem and Motronic engines is that the top timing wheel is machined especially to work with the cam angle sensor."

adamnreeves · Post by **adamnreeves** » Sat Jan 07, 2012 12:20 am

Look at this diagram of the cam wheel, the long slots are different and I am wondering if this is how they do it. Sadly my cam wheel does not have these slots which is strange as the cam wheel is the original. I only changed the cam and the timing cover.

DEVONMAN · Post by **DEVONMAN** » Sat Jan 07, 2012 9:52 am

I think the drawing is of Thor wheel and your photo is of a Gems wheel.
I think either should work but you need to check with the MS3 guys.

One problem you will have however is that even if you machine out the hole for the sensor in your cover, the standard sensor will not reach the camshaft wheel. The serp dizzy type cover is about 20mm fatter than a non dizzy type cover and you will need to find a sensor with a longer reach.

Regards Denis

adamnreeves · Post by **adamnreeves** » Sat Jan 07, 2012 10:39 am

Very good points devonman. That being the case maybe a trigger wheel some spacers and a longer cambolt is the way forward. I'll as the MS3 guys as suggested.

daxtojeiro · Post by **daxtojeiro** » Sat Jan 07, 2012 12:55 pm

From what Shaun tells me (V8D) the cam gear already has a flag on in that the sensor would detect. Having not seen inside there on my engine I couldnt comment for sure.

The MS3 doesnt mind when it see's the cam signal or for how long it lasts. Basically when cranking it waits to see either a leading or trailing edge.
Once its seen this it knows (due to the settings you put in it) where it is the next time it see's the first tooth from the crank.
Once the engine is running you could, in theory, disconnect it until you want to restart the engine. If it doesnt see the cam signal then it simply goes into wasted spark / semi-seq mode,
Phil

DEVONMAN · Post by **DEVONMAN** » Sat Jan 07, 2012 12:57 pm

adamnreeves wrote:Very good points devonman. That being the case maybe a trigger wheel some spacers and a longer cambolt is the way forward. I'll as the MS3 guys as suggested.

Yeah! that's sounds possible, a trigger wheel with just one stud on it to line up with the sensor at No1 TDC firing stroke. (I think).
Same idea as say a ford Zetec sensor which picks up the high point of on one of the inlet cam lobes.

Also need a dowel into the camshaft wheel to lock it in one position.

Have fun

Denis

stevieturbo · Post by **stevieturbo** » Sat Jan 07, 2012 1:08 pm

daxtojeiro wrote:From what Shaun tells me (V8D) the cam gear already has a flag on in that the sensor would detect. Having not seen inside there on my engine I couldnt comment for sure.

The MS3 doesnt mind when it see's the cam signal or for how long it lasts. Basically when cranking it waits to see either a leading or trailing edge.
Once its seen this it knows (due to the settings you put in it) where it is the next time it see's the first tooth from the crank.
Once the engine is running you could, in theory, disconnect it until you want to restart the engine. If it doesnt see the cam signal then it simply goes into wasted spark / semi-seq mode,
Phil

Does it actually revert to batch if it loses sync though ? Surely the fuel map will map will be different, and if you were using COP, you'd suddenly lose some sparks ?

I know that some ecu's ( Motec ) religiously look for a cam signal. Without both cam and crank, engine will stop.
Other ecu's once synced up will allow you t ignore the cam completely, or above a user defined rpm. It is always running fully sequential, it just doesnt need to be reminded every rotation where No 1 is.

The former is I guess the best and safest option. The latter can be handy if the cam trigger isnt stable for whatever reason.

DaveEFI · Post by **DaveEFI** » Sat Jan 07, 2012 1:50 pm

DEVONMAN wrote:
adamnreeves wrote:Very good points devonman. That being the case maybe a trigger wheel some spacers and a longer cambolt is the way forward. I'll as the MS3 guys as suggested.
Yeah! that's sounds possible, a trigger wheel with just one stud on it to line up with the sensor at No1 TDC firing stroke. (I think).
Same idea as say a ford Zetec sensor which picks up the high point of on one of the inlet cam lobes.

Also need a dowel into the camshaft wheel to lock it in one position.

Have fun

Denis

Unlike the crank sensor, the cam one isn't critical position wise. It is only telling the ECU which stroke out of four the engine is on. I'd say you could just drill a hole in the cam cog and use a hall effect sensor to read that.

daxtojeiro · Post by **daxtojeiro** » Sat Jan 07, 2012 4:14 pm

stevieturbo wrote:
daxtojeiro wrote:From what Shaun tells me (V8D) the cam gear already has a flag on in that the sensor would detect. Having not seen inside there on my engine I couldnt comment for sure.

The MS3 doesnt mind when it see's the cam signal or for how long it lasts. Basically when cranking it waits to see either a leading or trailing edge.
Once its seen this it knows (due to the settings you put in it) where it is the next time it see's the first tooth from the crank.
Once the engine is running you could, in theory, disconnect it until you want to restart the engine. If it doesnt see the cam signal then it simply goes into wasted spark / semi-seq mode,
Phil
Does it actually revert to batch if it loses sync though ? Surely the fuel map will map will be different, and if you were using COP, you'd suddenly lose some sparks ?

I know that some ecu's ( Motec ) religiously look for a cam signal. Without both cam and crank, engine will stop.
Other ecu's once synced up will allow you t ignore the cam completely, or above a user defined rpm. It is always running fully sequential, it just doesnt need to be reminded every rotation where No 1 is.

The former is I guess the best and safest option. The latter can be handy if the cam trigger isnt stable for whatever reason.

Sorry, didnt explain that well. It wont revert to wasted once its running. It ignores the cam input once its syncronised onto the crank / cam signals, but if it doesnt see a cam signal then it will run wasted spark and seq fuel, but the fuel may not be on the correct sequence, but this wont make any real world difference in the running,
Phil