TIMING Question

R

rx7chris

New member
On a 12a motor can you take out the distributor and move it one tooth to pick more timeing advance? I've currently got the distributor in full advance (full clockwise twist) and i've only got 10 or 12 deg. of advance. I'd at least like to get close to the stock 20. Any advice on this would be greatly appreciated.

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Chris
IT7 #88 **FOR SALE**
PowerTrip Racing
http://www.geocities.com/ptripracing/
 
Not to hijack your thread, but while we're on the subject, is everyone "locking down" the distributor? If so, what's the recommended approach? I've been told to tack weld it, but I'm afraid I'll screw something up.
 
Thief!!!

haha j/k

Never heard of tacking it down. I just use the nut on the side, seems to hold it just fine. just check it every once in a while. I figure as soon as you tack it, murphy's law will come in and you'll have to replace it.

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Chris
IT7 #88 **FOR SALE**
PowerTrip Racing
http://www.geocities.com/ptripracing/
 
Yes you can move it a tooth.

By locking it down, I believe he's speaking of the advance mechanisms. Never done it, just check/set the timing at full advance as that's where you'll be at race rpms anyway.

For those of you who have locked it down, does that much advance at cranking speeds make it extra hard on the starter?

Ben, your part is on the way. Had to make an unexpected stop at home before heading to the track.



[This message has been edited by Quickshoe (edited May 02, 2003).]
 
ok, cool

ummmmm

which way??

do i just unbolt it and pull it out or what? Thanks again.
Is it common that 12a's will loose time so quickly? had it timed about a yr ago. was supposed to be at 20, but when i checked it before yesterday it was 10 retarded? should i be looking somewhere else for problems?

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Chris
IT7 #88 **FOR SALE**
PowerTrip Racing
http://www.geocities.com/ptripracing/
 
Chris, again I am not an expert but if the nut is tight that holds the distributor to the engine & it lost a total of 30 degrees something stinks & I would say it's a wonder that it runs. If you can get only 10*ATDC maybe the thing is off already by one tooth.

Do you have a workshop manual. It's
cool.gif
to have a workshop manual. It details timming & removal of the distributor.

For removing the distributor:

Align the LEADING plug timing mark on the eccentric shaft pulley with the indicator pin on the front cover. If your looking through the radiator at the pulley the pulley rotates clockwise & the first mark on the pulley that comes/aligns to the pointer on the cover is the leading timing mark.

Open up the distributor cap & make a precision mark on the inside of the distributor housing exactly where the rotor is pointing. Also mark the hold down bracket with reference to the hold down stud before removing the nut.

When you pull the distributor out there is a gear at the bottom end of the assembly. There will be a tally/paint mark on the gear hub & there will be a tally/paint mark on the distributor housing. When your rotor is pointing to the precision mark you made inside the distributor housing these two tally/paint marks should be aligned. If the tally/paint marks are not aligned the distributor was assembled to the engine wrong. Being that I'm kind of anal therefor I would make sure the distributor is installed correctly with the tally marks aligned.

Ya re-assemble the distributor backwards to these take apart instructions. If your looking to get more than the spec of 20* ATDC you can get more by fiddeling with the plate in the distributor with the gear installed per the above.

Again if you don't have a manual hollor back that you don't have a manual
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& as slow as I type I will provide more information.

Have Fun
wink.gif

David
 
Something is fishy there! Check any and all things that could affect the timing.

Are you sure that:

The timing marks are accurate?
you are using the right wire? Shoud use the leading wire (lowest) on the #1 (closest to the front) plug.
there isn't an internal issue with the distr.?
The pulley is correct.

I know these are obvious, but I like to remind myself of the obvious sometimes.



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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]
 
Chris,
First, something is wrong. You can get up to 25 deg advance with the dist in the correct position so check that first. As a note, the max advance I would recommend is 22 degs masured at 5000 rpm with no vac advance hook up . Anything over that is quite risky. Align the pulley as David instructed. Yank the distributer and leave the rotor on it. On the dist gear is a black dot and on the dist shaft, there is a mark at the bottom(a bump) by the gear. Note, don't confuse the roll pin that holds the gear on the shaft for the black dot. Align the marks(the dot and the bump) and place the the dist back in holding the rotor in line with the side of the engine block. Let's call that three o'clock where the rotor is pointing.(Mega note: when the dist gear contacts the dist drive gear in the engine, the rotor will move to the four o'clock position) Lock it down and make your adjustments. Man, it is difficult to explain all this in writing
eek.gif
As Jake said,( may be redundant but you never know) Front bottom plug is leading, where you check leading timing. Hope all this makes sense.
Ray
 
Thanks for all the help guys, but at this point its gonna be a while till i have to worry about timing it again.

Water temps in the 350 to 400 deg range are bad right?!?!

No more wankel 'n for a liitle while.

while at the track before she blew i did get andy from asap to look at it, not sure what he found but he was able to get the right advance in it.

Thanks, again guys, i might have it rebuilt in time for daytona in aug.

if anybody wants a good deal on IT7 roller, make an offer

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Chris
IT7 #88 **FOR SALE**
PowerTrip Racing
http://www.geocities.com/ptripracing/
 
****note****


Andy had nothing to do with it letting go, been fighting a temperature problem since i got the motor.

By the way do you guys run a thermostat, restrictor plate, nothing, thinkin that might have been part of the problem.

Thanks again for the help

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Chris
IT7 #88 **FOR SALE**
PowerTrip Racing
http://www.geocities.com/ptripracing/
 
Chris,

I ran a gutted thermostat/restrictor.

If you removed the thermostat and didn't plug the water bypass you effectively created a very noisy water heater. Very little water flow through the radiator.

Sorry to hear about your problems.

-D
 
I'm running a block plug in the bypass. I am goin to run a gutted thermostat and see what that does. What about the thermostat in the oil cooler? I understand the oil cooler does about 1/3 of the cooling for the motor.

As far as the damage from the overheat. Can you say lucky? Have to replace the front rotor housing, have the side housings lapped, and put her back together. Think i got out of it pretty easy.

Thanks again for the help.

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Chris
IT7 #88 **FOR SALE**
PowerTrip Racing
http://www.geocities.com/ptripracing/
 
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