bl85c, your zip file doesn't seem to have any useable files in it...? I also changed the base timing to 70 and returned the coolant tables back to normal. seems to work.

I still can't figure out why it's breaking up on top end (independent of load)

Also, I can't figure out why I can not command timing greater than 20* at idle. I put 21 in the table and got 20 on the timing tab (close enough). I put 26 in the idle area of the table and still see 20 on the tab.

 

Try it now. It opened up fine for me but I went ahead and made a few tweaks and uploaded it again. You need the base set to 60*, the max to 0 and the min set to -70.

 

oh yeah, I actually had the reference angle set to 60. I plugged in RBob's numbers above into the hex editor for Max Spark Advance and it calculated to 80* with the xdf I'm using. This is probably my problem. should I set it to 90? or 0?

 

I modified the xdf formulas.
set Ref Angle to 60
set Max SA to -0.00 (@$1D; 16bit; 0.3515678 x + -23040.0000000)
set Min SA to -69.97 (@$1F; 16bit; 0.3515678 x + -23040.0000000)

I don't understand why Max spark advance is a negative number? Even so, I should be able to command 60* of timing now, right? (relative to #1 TDC)

 

You don't need to change the max spark, leave it positive. Only min spark uses that formula.

 

Could I still use the crank sensor in my 3.4 block?

 

That's the easy way to do it.

 

I can't believe I missed this thread. I should have this done with just one trip to the junk yard. Would a coil pack from a L67 (supercharged 3800) work? I have a spare for my moms car somewhere in my room.

 

No, it uses a different sensor & a completely different set of reluctors.

 

Okay, Thank you. 3.4 4thgens are all over the junkyards here. I'll see if I can pick up the stuff this weekend. If I get it to work, I'll be getting some alu heads and 3400 pistons ( I dont want super compression. )

 

Just one more question (probably simple, but I like to ask questions ) how would you adjust timing with out a distributor?

 

Since the topic is already on the table, maverick or bl85c, could one of you tell us what we have to do to use the DIS system already on the 3.4? I'm guessing its just a matter of wiring it into the harness, assuming the ecm can even run that setup? Because I'm not doing a hybrid swap yet, but eventually will be, and atm I'm prepping to swap to the 3.4, so would make sense to do it now, plus I would rather have DIS anyway..

 

You don't have too adjust the timing. The trigger wheel is part of the crank and is set for 10* BTDC. Be sure to read the posts about getting the ECM timing parameters set up correctly. Need to chip burn to use a DIS set up.

RBob.

 

Yep. The only reason you would need to adjust base timing is if you made your own reluctor & sensor bracket. The sensor's already positioned in the 3.4 block. 3rd gen RS just follow the directions in the 1st post. the 3.4 coil pack is essentially the same as the 3x00 stuff. You either need to swap to a '165 ecm & use the bin I made for DIS or hack into the stock pcm so you can change the min & max spark and the refrence angle. I don't think there's any publicly available hack or bin definiton for the stock pcm that has those.

 

3rd gen RS, he's a little off. There are FWD 60* cars that run the 302... Namely J-bodies (just about any pre-87 2.8 MFI). Just grab the chips, ignition coil pack with module and wiring, plug it all in, and go. Unless you need to tune that cam of yours yet. In which case, I'd still go with the chip for a base tune and adjust accordingly. You NEED to grab the yellow and purple wiring from the module to the 7x sensor in the back of the engine, unless you already have it and aren't using it, or the ECM won't know the engine is trying to run. $3A does allow spark timing to be changed as well.

 

Yup! Same as $a1, just use a memcal out of a 7730 in a j-body and it will run fine (unless you have a no, or near-no-vac cam lol). The remainder is wiring it into your harness to match, I have a diagram somewhere, but it's basically the same wiring on a dizzy as DIS. I have several 4th generation f-body motors running on a 1227727/1227730 with a conversion harness I created usinig $a1 from the j-bodies (well a few 93 autos and a few 94-95 manuals). Only issue I have now is controlling the 94-95 4l60e, but have read that I can use a TBI ECM from a 4l70 truck to control them and just so happens I have a 95 Camaro that was shipped to the shop for a motor & ECM swap, along with the request for fabricating some long headers, so we will soon find out

Anyways, back on topic lol.

 

MPFI? I thought all the fwd iron head stuff was tbi. Or are we talking about the early alum head 2.8's? So he would have to convert to speed density. I can see doing this if you don't intend on doing much with your motor but why not convert to a more useful pcm like a '730 or '165?

 

By the way 3rd gen RS, is that a '302 or an '870 in your car? '85's can have either, mine was an '870.

 

I was referring to the 302 ECM installed in the 86 models... Yes, they were MFI and used a MAF, and they can be a pain in the rear to find. I'm not sure if they used a distributor or coil pack or not, however.

You can't use a MEMCAL in a 302, BTW. Can't even use the chip out of one, either, as they aren't the same chip. Unless it's the other one (870, I guess), which I have no idea about. If it does have a MEMCAL, I have 3 of them I'm looking to get rid of from FWD cars.

And, other than the CKP sensor wiring, the wiring to the DIS coil pack is identical to that of the distributor system (unless you're looking at Buick parts, which are still pretty much the same except for a couple of extra wires). They still have the white, purple, black, and tan wires, with the white tach and pink power wires.

 

The '870 is a P3 ecm like the '302 so no memcal. Now that you mention it I recall seeing a cavalier in the scrapyard a few years ago that had the same induction as the camaro/firebirds had. I just passed it off as some kid f'ing around with his car. I'm pretty sure it was distributor. Whatever the case I still haven't found a definition file that has min, max and base spark values for the '302.

 

$3A, as defined as being for the 302 by the TunerPro site, has min, max, and any other spark value you could possibly want to adjust. Works for the HNJ bin file I've been looking over (just for kicks, going with a BAWX and $88). But, other than that, it's very complex as compared to $88.

 

... would that one also happen to have the maf table scalars? That might be mine from a number of years ago. I lost the original on my old computer and didn't think I uploaded it anywhere.

 

I forget some of you guys have the early f-bodies and was referring to wiring the '7730 that cam in the 89-92's when I was talking about swapping in the correct memcal for a DIS conversion.

The Gen II engine wasn't introduced until 1987, and was the first 660 that used DIS...

http://60degreev6.com/content.php/29...V6-Family-Tree

 

Which is why, if I ever get it right, I'm swapping to the 90-92 harness and 730. Meaning, if I can ever figure out that ignition problem...

bl85, it could be yours, not sure. There are a couple different spark tables, Spark Advance vs RPM vs Load, Power Enrichment Spark (deg), Coolant Compensation Spark vs Load, Highway Mode Spark vs Load, and of course min spark, initial spark, max spark. There are others, just a longer list.

 

You guys have really come a long way sence last I was here this mess is awesome!! I wish we lived somewhere close it would have been cool to see this materialize.

~Couch

 

I think the interest in these motors is there, people just need the hardware & some direction.

 

I agree development continues to be ongoing. The work started by Auto nuts in the 80's resonates in future technology. I am now working with a school developing, and researching prototype futuristic propusion systems. This sort of stuff fasinates me because I can put it to use. A little bit of thinking goes a long way with anything.

~Couch

 

And money...and energy drinks, last time I worked on an engine drink I had plenty... just tore down a 3.4 from near complete to pretty much shortblock with none at all, or anything other than water to drink, sucked =/

 

Here's some inspiration for some of you guys. This is one of my customers using a top end from us. The chambers were opened up slightly to achieve an 11.38:1 compression ratio on stock 3.4 pistons (8cc) and head gaskets (.040"), LS6 valve springs, LS1 seats, Viton valve seals, custom pushrods, 3400 upper manifold (to clear the cowl), 3500 heads, 3500 LIM, and a custom 272 cam I came up with as the composer for the symphony - all in a 1969 Datsun roadster...

http://www.youtube.com/watch?v=0JAO3_2ztNs

 

Is that your car, or do you know how I can reach the person who's it is? Would like to know some stuff about it...I plan to swap to 3500 heads and intake on stock pistons myself and have been wondering how much cam I will need with the static CR of 12.33:1, which the CR you listed IS dynamic right? If not I think you calculated wrong...Anyways, that thing is a beast and I can't wait to get my hybrid going...but first I gotta get the 3.4 in, doing it this week with any luck 1

 

Not my car, one of my customers

I have built a built a business around these hybrid swaps. Trust me I did not calculate it wrong. The chambers are 32.4cc in stock configuration, I opened them up to 36.6cc (IIRC, this was months ago). Usually the guys are running 3500 or 3400 head gaskets, but they are too thick really to have a decent quench. Since the 3400 has the piston protruding from the block at .020" and the 3500 is .010", while the 3.4 has them .010" down in the hole, this affects the piston to head clearance. This particular customer wanted to save the quench, so we used .040" thick 3.4 head gaskets and opened the chambers, the chambers were slightly decreased after the modification since we took .003" off the deck surface after the procedure...





There's a guy here in FL running .030" over 3.4 DOHC pistons (~5cc valve reliefs in the pistons) and 3500 heads with a medium cam and 89 pump gas. The static compression is 12.6:1, but that doesn't make nearly as much difference with the fast burn chambers and excellent port design as it does on your typical iron heads.

With 3.4 pistons, 3500 heads and 3500 head gaskets (3.8" bore vs. the 3.4's 3.75" and .060" height vs .040") your static compression will be 11.56:1.

PM me or click the link in my signature to keep the thread on topic

 

Just want to double check on this, but the wires you referred to as dist, were those on the 4 pin connector that plugged into the dizzy right? Meaning in essence that the 4 pin connector(the one the same style as the injector harness uses) for the coil isn't used at all if I'm correct? Just noticed the 4 pin sitting there looking out of place while trying to work out vacuum lines.

 

That's correct, you move the wires from the distributor connector to the DIS plug and discard the distributor plug.

 

OK, how do I cut this thing...I am a bit confused here.

In both pictures the keyway is up and TDC is to the right on the balancer.

In the top picture the template is flipped to were the TDC mark is to the left when the keyway is up;
This way the template TDC mark is some odd degrees after the TDC on the balancer.
I would have to cut marks and fill in machined marks on balancer.

In the bottom picture the template is flipped to were the TDC mark is to the right when the keyway is up;
This way the template TDC mark is 120* after TDC (Is this suppose to be like that?) 2 of the machined marks on the balancer line up with the marks on the template.

I would have to cut 4 new slots and widen the original slots.

 

The position of the notches will be determined by where your sensor will be mounted.

 

Good point forgot to mention where it is.

The sensor is mounted at the original serpentine belt timing tab position at 0* or TDC.

It is here.

 

If you don't have an AIR pump, you can either get or make a bracket to mount the DIS sensor where the lower AIR pump bracket is. Then, you cut the notches in each of the TDC marks and 3 between. You will put the #1 sync notch next to the notch that the sensor lines up at with #1 at TDC.

 

I want to keep it on the timing tab, I already mounted it. The middle of the sensor is mounted at TDC.

 

Does this apply to GM? If so, I just place my first two marks 50 and 60 degrees in front of the sensor (TDC mark) and 60 all around.

So the sync mark says hey #1 is coming up...right?

Want to get this right...I already slotted one balancer wrong grrr. >.<

 

The keyway is backwards on that. The 10* & 60* notches should be top and to the left with the keyway straight up.

 

That would make the 10* and 60* mark about 80-90 degrees before tdc according to the balancers TDC mark.

From the research I've done, the goal is to sync before TDC is seen by the sensor so by placing it right after TDC is knows when TDC is coming up.

If it works like below, the picture from above showing how to move the sensor to any location should work. Just place engine at TDC, and rotate your missing tooth or the sync notch to the right from the sensor location for clockwise rotational cranks x amount of degrees. This makes the sensor location independent. So whenever you pass your sync tooth the first missing tooth to be seen is TDC always and it knows to start at 1 each time.

Makes sense?

 

Got me lost but im trying to follow this. I need to knotch a reluctor ring up soon.

 

What I take from it is:

1. Set engine to TDC
2. Determine where your sensor will be and space 0.75-1mm away from reluctor
3. Line sync notch on reluctor to sensor
4. Depending if your crank turns clockwise (which ours does) turn your reluctor to the right 50*.

This ensures 1 is seen first after the sync notch and in the correct order. 1,2,3,4,5,6, 7 (sync)...and repeat.

As the photo shows you above...but this is all untested...on my part...
The template itself is right, it is just where you place it.

 

Everytime I set a trigger wheel up I reference this page to refresh my memory on where the home notch needs to be.

http://www.megamanual.com/ms2/GM_DIS.htm

 

Yeah so what I said above makes sense. If each notch represent TDC for a cylinder...then the sync notch is 10* before the 6th cylinder TDC, telling the ECM? that the first cylinder is next.

I'm going to be trying all this soon enough.

 

Uhhh, read it again, the sync notch is 10 degrees after TDC #1.

Also the sync notch doesn't tell the ECM anything, the ECM has no idea at what point of the firing order the engine is. It just gets pulses from the ICM every time a coil fires. The ICM uses the sync notch to know what coil to fire. Because of this one sync notch it usually takes between 360 to 720 degrees of crank rotation to fire at start up. Consumers didn't like the "long crank" and so GM developed other "fast fire" systems, like the N* and 3800 ignitions systems that either use a unique crank trigger wheel or high res crank sensors in conjunction with the low res to get the ICM to fire off the proper cylinders sooner in the crank cycle. The last few sentences are bot important to getting a crank trigger to work, but I posted as an FYI to how or why the engine may take a "long crank" to start.

 

Very good link six shooter. Thanks

 

It's just a matter of where the notch has to be in relation to the sensor...that's all I care about. My sensor is at TDC while my crank is set to TDC, where should my double notch be, 50,60 degrees after it, before it, or dead on TDC.

I'm not sure but the only thing that makes sense to me is putting the sync notch 50 degrees to the right of TDC.

 

Really?

Have you even clicked on the megamanual link I posted?

It's SPELLED out in that link EXACTLY where the sync notch should be when setting up the crank trigger.

The sensor could be anywhere around the sensor when engine is set to TDC #1 and still be correct, it's a matter of clocking the trigger wheel.

As two examples go:

My 1985 GMC Jimmy:




My Datsun (same wheel and part of the trigger mount from the Jimmy):




As you can see, the sensor locations are quite different between the applications, but the timing mark is in a very similar location between the two engines (approx 1:30). SO all you need to worry about is that the sync notch passes the sensor at the correct angle in relation to TDC. It's all really spelled out in the link I provided.

Also, do yourself a favour and build a separate trigger wheel that gets bolted to the engine, there are issues that can arise with proper timing when using the rubber mounted ring on the harmonic balancer as a trigger wheel.

 

I'm aware it doesn't matter where the sensor is. It matters how the trigger is placed.

"On 2.8L/3.1L V6 engines, the module skips the number 1 notch after the sync signal and fires the 2-5 cylinders on the signal from notch 2. Notch 3 is skipped and notch 4 fires the 3-6 cylinder pair. Finally, notch 6 is used to fire the 1-4 pair. Cylinders fire in 1-2-3 sequence during one crankshaft revolution and 4-5-6 on the next."

According to megasquirt, each notch coincides with TDC, so notch 1 must line up with the sensor when the crank is at TDC.

In your bottom picture you have the engine at TDC, and the sync notch place there?