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.