[bobbb]

Hi, would like to get some opinions/advice plz
Is there any reason to do an AFM delete valley cover for an M6?

They story is - bought a M6 SS on an auction with rear damage, no damage to the engine.
By the looks of it the previous owner had a whipple supercharger which was removed before it went on auction (stickers on the car and various bolts loose).
The car stalled on idle and did not run at all. So I reflashed the ECM to stock, drained ethanol from the tank and filled with petrol. Now it accelerates ok, but idle is very uneven, sometimes stalls.
I see it has Katech AFM delete valley cover, not sure if any other mods inside.

But why do an AFM delete on a M6? And if the lifters were changed, but now it has stock ECM flash - would that affect idle or should I look for problems elsewhere?

And sometimes I get P0011 - intake camshaft position performance. But not all the time.
If cam was changed would it affect idle with stock flash?
Acceleration is ok, just idle is the problem.

Thanks.

[squish72]

Idle would for sure be affected if it has a cam and stock tune file. If they did the afm delete I would guess the did a cam as well. It's not guaranteed but while youre in there doing the delete it would be worth going the extra step. I would recommend getting something to log the car and see what the engine is doing

[bobbb]

Hmm... OK, I think it would be easier to get it back to stock than get a tune in the place that I am at now.

So if I was to put in a stock cam, what about the lifters, I understand its necessary to put in non-AFM lifters with Katech cover (are M6 lifters AFM or non-AFM)?
And is the cam different for AFM/non-AFM?

And why do the delete for the M6 at all?

[Joshinator99]

Originally Posted by bobbb

Hi, would like to get some opinions/advice plz
Is there any reason to do an AFM delete valley cover for an M6?

They story is - bought a M6 SS on an auction with rear damage, no damage to the engine.
By the looks of it the previous owner had a whipple supercharger which was removed before it went on auction (stickers on the car and various bolts loose).
The car stalled on idle and did not run at all. So I reflashed the ECM to stock, drained ethanol from the tank and filled with petrol. Now it accelerates ok, but idle is very uneven, sometimes stalls.
I see it has Katech AFM delete valley cover, not sure if any other mods inside.

But why do an AFM delete on a M6? And if the lifters were changed, but now it has stock ECM flash - would that affect idle or should I look for problems elsewhere?

And sometimes I get P0011 - intake camshaft position performance. But not all the time.
If cam was changed would it affect idle with stock flash?
Acceleration is ok, just idle is the problem.

Thanks.

If he did an aftermarket cam it was likely one that limited (or eliminated) variable cam timing. Flashing it back to stock will conflict with that aftermarket cam if VVT is eliminated. Stock tune generally doesn’t work with an aftermarket cam either, especially idle speed.

M6 cars are non-AFM but believe they still had the AFM lifters. You normally ditch those with a performance cam.

[bobbb]

Originally Posted by Joshinator99

If he did an aftermarket cam it was likely one that limited (or eliminated) variable cam timing. Flashing it back to stock will conflict with that aftermarket cam if VVT is eliminated. Stock tune generally doesn’t work with an aftermarket cam either, especially idle speed.

M6 cars are non-AFM but believe they still had the AFM lifters. You normally ditch those with a performance cam.

So let's say it has some other cam and lifters and I put back a stock cam, would it work with whatever lifters are there or should I also get a set of OEM lifters as well?

[Joshinator99]

Originally Posted by bobbb

So let's say it has some other cam and lifters and I put back a stock cam, would it work with whatever lifters are there or should I also get a set of OEM lifters as well?

Stock cam should work with whatever lifters are in there (Edit: nope lol), but you might need to double check that the pushrods are the right length. Probably easier to just buy stock everything (cam, lifters, pushrods, valley cover, etc) from someone who upgraded assuming you are not modding the car.

[Mark114]

Originally Posted by bobbb

Hmm... OK, I think it would be easier to get it back to stock than get a tune in the place that I am at now.

You might consider a remote tune. There are a number of people that have very good reputations like Jannetty Racing and Pray Performance.

[KingLT1]

Originally Posted by bobbb

So let's say it has some other cam and lifters and I put back a stock cam, would it work with whatever lifters are there or should I also get a set of OEM lifters as well?

If you put a stock cam back in then you have to source 8 afm lifters. The stock cam has 8 lobes that are specific for the afm lifters and will not work with standard hydraulic lifters.

[L78toLT1]

I've got a stock cam, lifters, trays & pushrods if you decide to return to stock. Removed them from my car at 16k miles.

[bobbb]

Thanks for the input guys, that helps.
Will try to find some local tuners if possible. Else... will probably swap out for stock parts and see how it goes on from there.
I've found the cover, cam, lifters (8?) and pushrods locally.

Any ideas if THIS is what i might need for an M6 ?

[KingLT1]

You need 8 standard hydraulic and 8 AFM lifters to be compatible with a stock LT1 cam shaft. AFM lifters have a big spring on the end of them. Click on the link for example of the lifters used in most GM small blocks that have AFM.

https://www.michiganmotorsports.com/...gaAp0HEALw_wcB

[Tim M]

Originally Posted by KingLT1

You need 8 standard hydraulic and 8 AFM lifters to be compatible with a stock LT1 cam shaft. AFM lifters have a big spring on the end of them. Click on the link for example of the lifters used in most GM small blocks that have AFM.

How are the LT1 lobes different between AFM and non-AFM?

If you tune out the AFM and install the eliminator, are you not able to run the same non-AFM lifter on all 16 lobes?

[KingLT1]

Originally Posted by Tim M

How are the LT1 lobes different between AFM and non-AFM?

If you tune out the AFM and install the eliminator, are you not able to run the same non-AFM lifter on all 16 lobes?

The information is out there just search it. You can not delete AFM mechanically without swapping the cam to a non AFM cam. It has been this way since the GEN 4 LS days. Here is one link with some info. https://lt1swap.com/afm_delete.htm


What you "might" be able to do is purchase a LT5 OEM camshaft from scoggin dickey since it is NON AFM and run that in a LT1 with 16 standard hydraulic lifters. The LT5 cam is similar in specs to the LT1 cam minus the AFM.

https://sdparts.com/i-24136024-genui...MaAoZ3EALw_wcB

[L78toLT1]

Originally Posted by Tim M

How are the LT1 lobes different between AFM and non-AFM?

If you tune out the AFM and install the eliminator, are you not able to run the same non-AFM lifter on all 16 lobes?

I doubt it. The M6 cars have the AFM disabled, but they still have the AFM lifters & springs