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-   Rotary Engine Building, Porting & Swaps (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/)
-   -   Direct Fire / Ignition / 12a ? (https://www.nopistons.com/rotary-engine-building-porting-swaps-55/direct-fire-ignition-12a-69178/)

alexlorenzo 03-01-2008 04:41 PM

I've been building a 12a rotary for a couple of mths..

I'm trying to run direct fire.



Problem:

I installed two blaster3 msd coils and msd ignition box (6al) per instructions.

I got spark in the spark plugs, coils are working.

Engine turns but it wont start.



What am I doing wrong?



I checked the timing.

I put distributor on timing by mark on gear.



Any info / suggestions / links would be appreciated.

sen2two 03-01-2008 07:20 PM

you have correct timeing, and good spark...



i say fuel problem...



check plugs for strong smell of fuel or saturation.

j9fd3s 03-02-2008 11:16 AM

if theres spark, and the timings within 20degrees, it should start on just about anything resembling gas, i'd pour a little fuel down the carb, and see if it starts.



if it does, then you've got a fuel problem.



if it doesnt, maybe you're front pulley timing marks are off? compression?

alexlorenzo 03-02-2008 04:52 PM

Bought new plugs .. engine cranks like it wants to start.. took out the plugs and they are soaked in gas.



?? anything ??



I double checked timing on crank and ignition.. everything seems to be on pt.



Unable to check compression.. don't have gauge.



Engine is j-ported.. would that be a poss cause of issue I'm having??

sen2two 03-03-2008 07:11 AM

are you carbed or fuel injected???



your flooding it...

ColinRX7 03-03-2008 10:55 AM

Make sure the block has a solid ground to chassis. It's an easy thing to miss.



Soaked plugs won't want to fire, dry them off and reinstall when they get saturated, and continue diagnosis.



It's flooding for sure, I wouldn't worry about the ignition components now, I'd worry about fuel settings. But if you're really uncertain about the ignition, you can buy a cheap tool that goes inline with a spark plug wire to plug, and it has a light to verify the ignition is firing. Local auto store should have it. Sometimes insufficient ground can be the cause of no spark.

j9fd3s 03-03-2008 02:55 PM

if its flooded unplug the fuel pump, clean the plugs and crank it....

Tom93R1 03-06-2008 08:50 PM

Setting the pulley to 0 then the mark on the distributor gets you close but its still very easy to be a tooth off when you drop it in. I would try turning it a tooth either direction.

Lynn E. Hanover 03-07-2008 09:07 PM


Originally Posted by alexlorenzo' post='895696' date='Mar 2 2008, 03:52 PM
Bought new plugs .. engine cranks like it wants to start.. took out the plugs and they are soaked in gas.



?? anything ??



I double checked timing on crank and ignition.. everything seems to be on pt.



Unable to check compression.. don't have gauge.



Engine is j-ported.. would that be a poss cause of issue I'm having??





Assuming that the "J" bridgeport includes a much later closing point, yes it has a bad effect on starting.



Later closing means that some of the mixture is forced back into the manifold rather than being trapped and compressed in the closing chamber. So less volume to compress means what?



You have (in effect ) lowered the compression ratio. Less mixture, same head spacer = lower compression.



Lower compression means less heat of compression, and that means less fuel will vaporize and remains droplets, and that means easyier flooding and the few lights you get will be low energy fluffs and not the sharp fast burning high energy cracks you need to get a start.



First put a timing light on it with a plug out of each housing. Have a fire bottle standing by just in case.



Check the timing. Check the timing on the trailing wires as well. If the timing is right on the money, replace the plug wires to each clean dry plug and make sure that each plug is being fired. Check to be sure that there is oil pressure.



Still OK. Run a new chassis ground wire to one of the the bolts that holds the starter on the bellhousing.



With lower compression, engine cranking speed becomes very important. A fresh fully charged battery.



Make up and oil squirt can with gasoline and 6 tblspoons of cheap dino motor oil. With no temperature to start off with, the motor oil will not burn, but will add volume to the chamber raising the compression, and will seal the rotor up real well. There is no need to have the fuel pumps on at all.



All of this is done outside the shop. An engine fire is bad. An engine fire inside the shop is real bad. Put the plugs in and shoot three stroke of the fluid down each runner. With leather gloves on a leather jacket and eye protection, crack the throttle to just off idle so as not to limit airflow and spin it up. Now it has fuel, compression and correct timing. It will start or, you have not been telling the whole story.



It will keep running so long as you can keep squiting in fuel. It will be smoking like hell as well. Let it die.

Turn on the fuel pumps and repeat above, and the pump will keep it alive.



Lynn E. Hanover

Lynn E. Hanover 03-07-2008 09:13 PM


Originally Posted by alexlorenzo' post='895623' date='Mar 1 2008, 03:41 PM
I've been building a 12a rotary for a couple of mths..

I'm trying to run direct fire.



Problem:

I installed two blaster3 msd coils and msd ignition box (6al) per instructions.

I got spark in the spark plugs, coils are working.

Engine turns but it wont start.



What am I doing wrong?



I checked the timing.

I put distributor on timing by mark on gear.



Any info / suggestions / links would be appreciated.





The direct fire setup is only on the leading (bottom) plugs right? Both fire at the same time.



The trailing plugs (top) need to be distributed, cannot fire at the same time.



Lynn E. Hanover


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