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Hello to everybody.
I'm building a Mercury twin turbo v8 marine engine! It's like BBC 502 cubic inch twin turbo but it has efi and I'm wondering if my old Dta S80 supportsPlease that kind of crank pulley ! It has 24 teeth but some are smaller than the others!Also the camshaft pulley is strange too.I think the cam sensor will read half pulley one big tooth and the other half gap.Do you have any idea?

looks like you're trying to use the awful 24x from an early LS1 ?

Cam wheel is no problem, it's just a single tooth, albeit a large one. So totally usable.

IF...IF that is supposed to be a replica of the horrific 24x crank wheel the LS1 uses, then the falling edge of the teeth are all consistent, only the rising edge changes position throughout.

But I would say to get a proper 36-1 or 36-2, 60-2 etc etc type wheel for the crankshaft, it is far superior to that 24x LS1 crap.

From memory the falling edge of the cam tooth is around cyl1 TDC.

even something like this if you cannot make something up yourself.

https://www.holley.com/products/ignitio ... ts/556-113

As stevieturbo says, that trigger pattern is not supported on the S Series. However, it will be supported on the T Series in the not too distant future.

You'll need an external crank trigger to run that on an S80.

Alex DTA wrote: ↑Mon Mar 20, 2023 7:28 am As stevieturbo says, that trigger pattern is not supported on the S Series. However, it will be supported on the T Series in the not too distant future.

You'll need an external crank trigger to run that on an S80.

With one edge of a 24x being a regular edge....it can work in lieu of a more normal looking 24 tooth wheel. But the GM LS 24x is a crap wheel. It irks me when anyone goes out of their way to use it, when there are so much simpler and superior options

Thank you very much guys!I'll go with the safest way (36-1)

That is the sensible route to take.

stevieturbo wrote: ↑Mon Mar 20, 2023 12:56 pm

Alex DTA wrote: ↑Mon Mar 20, 2023 7:28 am As stevieturbo says, that trigger pattern is not supported on the S Series. However, it will be supported on the T Series in the not too distant future.

You'll need an external crank trigger to run that on an S80.

With one edge of a 24x being a regular edge....it can work in lieu of a more normal looking 24 tooth wheel. But the GM LS 24x is a crap wheel. It irks me when anyone goes out of their way to use it, when there are so much simpler and superior options

Nothing wrong with the trigger, as it's just a 24-0 trigger, if the falling edge is used.
S Series uses rising edge, so would require development to make it work, and there's no more development done on the S Series.
T Series can easily support that, so I'll add it when I have time.

Alex DTA wrote: ↑Wed Mar 22, 2023 4:06 am

stevieturbo wrote: ↑Mon Mar 20, 2023 12:56 pm

Alex DTA wrote: ↑Mon Mar 20, 2023 7:28 am As stevieturbo says, that trigger pattern is not supported on the S Series. However, it will be supported on the T Series in the not too distant future.

You'll need an external crank trigger to run that on an S80.

With one edge of a 24x being a regular edge....it can work in lieu of a more normal looking 24 tooth wheel. But the GM LS 24x is a crap wheel. It irks me when anyone goes out of their way to use it, when there are so much simpler and superior options

Nothing wrong with the trigger, as it's just a 24-0 trigger, if the falling edge is used.
S Series uses rising edge, so would require development to make it work, and there's no more development done on the S Series.
T Series can easily support that, so I'll add it when I have time.

The OEM GM wheel is a 2 piece, spot welded together piece of junk. It just is.

A 1 piece billet type wheel is of course a lot better...and if you decode it like an OEM wheel using both edges, it can give better cyl position info. But when using it on only the falling edge as a plain 24x wheel with no identifier...I see it as crap.
I would never recommend anyone uses a crank wheel with no TDC ID. It just makes zero sense. I would also dislike a plain 24 tooth, 12 tooth, whatever.
I can see no reason ever to run a crank wheel that doesn't have some sort of position identifier.ie, the missing tooth.

Whilst a missing tooth on the crank does make things 'easier', a no - missing tooth crank wheel in conjunction with a cam wheel providing cycle phase info / degrees can be workable. My first efi install used a 4 tooth crank wheel and a single tooth in the inlet cam (it was a bit ghetto!) Once the relationship between cam trigger point and #1 TDC was established, the firing point offset could be worked out to the next crank tooth. Admittedly it ran wasted spark for simplicity, sequential multi stage injection was used successfully, and if I ever get back to it, it will have a revised crank wheel -
36-1 as i've learnt my lesson (it'll improve starting also LOL!)