Small block Chevy Installation

[roarin_mouse]

Currently, I'm running an MSII on my ZZ-383 stroker with a RamJet intake. When the the MSIII is available, I will certainly get one. In order to run fully sequential, I'll need crank and cam sensing. Here's my question: Can I use a Vortec crank sensor and a Vortec distributor to achieve this? Obviously I'll be using the distributor for the cam signal only (and driving the oil pump). If this will work, please let me know so that I can start by adding the crank sensor ahead of time.

[muythaibxr]

On the distributor, you'd only want 1 tooth. It probably has 1 tooth per cylinder now, but you'd just want 1 tooth for the whole distributor.

Ken

[roarin_mouse]

I'm not really sure, but I think that the Vortec distributor is a one tooth deal. If anyone knows for sure, please speak up.

[Joe]

vortec dist is a 1x cam signal. vortec(L31) crank reluctor is a 4x. 4x works fine for a crank triggered dist( I run this on my truck) but is not enough for sequential.

Joe

[jsmcortina]

Four on the crank and one one the cam is sufficient for V8 sequential and coil on plug. However, you would get increased precision with more teeth on the crank wheel. e.g. a 36-1.

James

[roarin_mouse]

How would I install a 36-1 wheel on my ZZ-383? Currently, there is no crank sensor but I would like to know if someone makes a reluctor that fits. I do have access to a machine shop.

[roarin_mouse]

So...James, better precision? How much better are we talking about? How accurate would it be with the 4-0 (stock Vortec)crank reluctor and the stock vortec distributor reluctor?

[jsmcortina]

In your instance with a 4 tooth crank wheel, you are giving the Megasquirt engine position information every 90 degrees. Anywhere in between that it must calculate based on previous engine events where to fire the coils etc.

With a 36-1 for example, you give it engine position information every 10 degrees, so it only has 10degrees to calculate over.

I don't have any data on the actual accuracy gains. The 4 tooth wheel will certainly work and I'm sure it will work fine, but it might be worth looking into the 36-1 as a future upgrade.

James

[muythaibxr]

I've seen pretty good increases in power by using more teeth just because the timing is actually where you set it during hard acceleration.

I also don't have any numbers, but the data for accuracy is logged in the datalogs.

Ken

[roarin_mouse]

I appreciate what you guys are saying. On that note, does anyone know where I can get a 36-1 that will fit in place of a Vortec reluctor? I saw that EFI Connection has them but I think they're a bit pricey ($275.00).

[roarin_mouse]

I believe I'm going to buy a stock Vortec reluctor wheel and dimension it. From there, I'd like to have a custom wheel made with the same dimensions but with more teeth. It looks like the wheel is pretty small so I don't think that 60 teeth will be resolvable with the stock sensor (the pole area is fairly large). I was thinking of either a 16, 20, or 24 tooth wheel and using the highest of those that can be resolved. Will the firmware and Tuner Studio support these sizes? For the cam signal, I'll use the 2-1 Vortec distributor. Will there be a second variable reluctance amp in the MSIII (to accomodate the cam and crank signals)? Does anyone see any flaws with my approach?

[jsmcortina]

Those could all be ok. 16 teeth results in 22.5 degrees per tooth, but we do support 0.1deg tooth sizes so that should be ok. 18 teeth would be 20 degrees.

The MS3X is planned to have a VR conditioner on board so that will give you crank and cam conditioning options.

James

[roarin_mouse]

Does that mean that we can use reluctors that are other than 4,8,12,16,20...teeth for an 8-cylinder engine? The old manual says that the number of teeth must be #of cylinders/2 x an integer.

[jsmcortina]

On further thought, you are correct. At present 16 will work and 18 will not (on a V8.) There's one section of the initialisation code that would have a problem with 18.

James

[Joe]

The OD of an L31 4x wheel is 4.00" I have a 4x wheel in my truck working well. I purchased a 36-1 4" wheel from DIYAUTOTUNE with the hopes of getting a machinest buddy of mine to modify it for an SBC. I like the vortec behind the timing cover setup and am hoping to come up with something for it. If you come up with a behind the cover alternative please post. If you are creative and have a machinest friend order an L21 reluctor. It's 4"OD but ID is to large(BBC). The L21 wheel is a 24x.

The eficonnection SBC wheel is basically an L21 wheel with a smaller ID. Keep in mind also you will need the L21 crank sensor.

Joe

[roarin_mouse]

I saw a picture of the big block reluctor and it looks as though this would not work for MS. The teeth are cut as though there was a coded output (perhaps PCM). I ordered a Vortec reluctor wheel (for dimensioning purposes) and will then have some 24-1 or 24-2 wheels made that will fit under the Vortec cover and use the Vortec sensor. It looks like the sensor is a Hall Effect type as there are three pins. The Vortec distributor (Cam Position Sensor) also is a three pin device. That'll make it easy to set up the triggering. Also to note; the CPS is the same for the BBC as the SBC. Amazon has them (Standard Motor Products part number:PC123) for under $30.00. They also have the plastic Vortec timing covers (Dorman 635-505) for under $27.00 w/free shipping.

Question: Is there any advantage to a 24-2 over a 24-1 wheel? I will make whichever one is best so if anyone has a valid argument either way, please chime in.

[muythaibxr]

24-1 is better because it actually has more teeth. More teeth means less inaccuracy around the missing tooth.

Ken

[roarin_mouse]

Thanks for that, Ken. I guess it'll be a 24-1. Now I have to consider where to key the reluctor. Does the start or stop of a tooth have to correspond to a particular phase angle? Obviously I don't want the missing tooth to align with a critical point. Any help would be appreciated as I plan to get this reluctor design complete ASAP.

[Maglin]

You could look at an aftermarket SFI damper and get a 36-1 wheel from DYIautotune.com . You would sandwich the wheel between the crank pulley and the balancer. I don't have a Vortec here to compare but that is what I'm going to run on my turbo L88 sbc. Never thought about using a vortec distributer for the cam signal. I thought they where still a 8 tooth reluctor.

[LT401Vette]

That is my system too, I have a 60-2 tooth wheel sandwiched between the pulley and damper on my BBC, same setup when it was a small block.

On the old electromotive setup I had you had to set it up exactly 11 teeth from the missing tooth when at TDC, but with MS you have a lot more flexibility on where the missing tooth/teeth land because you can adjust for it pretty well all the way around.