3500 CPS Adapter

[Superdave]

Can you imagine turning a 3900 into a 60 degree 4.3L with a .2 inch stroke and cylinder bore.

craziness...

I do have a 2.8 crank about 12" away from a 3400 block right now.. i'm still thinking about building the 3.0 stroker to drop in my Z sometime next year...

[CNCguy]

Machined the slots in a dampener today and remounted it. It fired right up and ran like normal. I was looking around in my extra shelves and found nine peices of matial that I can use to make some prototype bolt-on reluctors. Pehaps we can make them this week. The modified dampener will work good for the initial application since there is limited space.

Here's a pic of the dampener after slotting. Not a great pic but you can see what was machined on it.

[prophiseer]

I gotta say . . . looks great so far! Correct me if I'm wrong, but aren't you going to have issues with the PCM's ignition advance on top of the adjustable advance?

BTW, though, on the N-bodies, there's a ton of space between the dampner and the fenderwell. The dampner is easily removable with the fenderwell splash shields out of the way.

[sprucegagt]

How are you going to verify that you are getting timing advance / retard?

[CNCguy]

The Advance/Retard feature was created for use on OBD-I cars. It allows the static timing to be changed and would not be changed often. Timing changes can be made for varations in fuel, boost etc.

[CNCguy]

Ok.... Here it is. A seperate reluctor ring that bolts to the dampener. I bolted it on the 3100, moved the CPS out to match and it fired right up. It mounts using (3) 3/8-16 Grade 8 Cap Screws. I need to make up a few more of the CPS mounts and get them over to Ben so he can get them on the store. I may check into having them powder coated since they are bare steel and will rust quickly.

[IsaacHayes]

Nice, easier to install too (no removing the pulley). Still wondering if it will bolt to an L body with the way that mount bolts around there.

So other than this and a TB adapter, that's all that's needed to run a complete 3500? Then someone can do a true dual exhaust!

[gpse3400]

Excellent! That's a nice kit!. Got one question is there anyway the crank sensor mount can be made of iron or steel? Because I have an axle support that bolts there and it is done up to 75 ftlbs, I'd like to not to have to go low on the torque.

[IsaacHayes]

If you have an axle support that bolts there (like I have a motor mount bracket that bolts there!) how is this going to affect the offset of the CPS holder? It would have to bolt on the outside, thus the thickness of the stock motor mount bracket or axle support bracket will move it away from the crank pulley that much.

EDIT: I guess you could keep adding washers until it moved the plate out enough to match it...

[prophiseer]

Defi looking forward to seeing this available!

[MidnightriderZ24]

very nice piece u got there. im wondering if u the 3 holes on the balancer are the same as the FFP UDP. would the rear metal bracket that bolts to the block for use in j bodies and L bodies affect the position?

[CNCguy]

If you have an axle support that bolts there (like I have a motor mount bracket that bolts there!) how is this going to affect the offset of the CPS holder? It would have to bolt on the outside, thus the thickness of the stock motor mount bracket or axle support bracket will move it away from the crank pulley that much.

EDIT: I guess you could keep adding washers until it moved the plate out enough to match it...

I would like to keep these as simple as possible to keep the costs down.

If all motor mount brackets are the same size, it would be a fairly easy fix. The brackets could be made to fit engines with a lower mount and also come with spacer rings to use on engines without the lower mount.

GPSE3400 - I will look into adding steel sleeves into the CPS mounts. The cost to machine a part from steel is more that the aluminum.

Can anyone measure the lower mounts and post the thickness of them. I don't have any for measurement. It needs to be a decent measurement done with calipers or micrometers.

[sprucegagt]

The Advance/Retard feature was created for use on OBD-I cars. It allows the static timing to be changed and would not be changed often. Timing changes can be made for varations in fuel, boost etc.

That's not what I was asking. What I want to know is how do you know the timing feature "works?" I take it you have scan data showing before and after results proving timing did increase or decrease?

[IsaacHayes]

Hmm, steel spacers and also making the CPS holder work with mount brackets and including spacers for vehicles that didn't use them sounds good. I unforntunaly can't get you the measurements. I'm sure someone can..

EDIT: Just dawned on me that you probably have to take off the crank pulley and put it on so it aligns with cyl #1 being TDC with the bolt on plate being in the right spot correct? Is it possible to find out TDC on #1 without taking off the heads?

[bszopi]

You should be able be able to locate TDC with the crank key...



And now that I've looked at the trigger again, I'm sure that the hole (not notch) in the wheel is to locate the line marking TDC on the damper.