Home page
SPONSOR AD SPONSOR AD

Topic: Ignition parts

in Forum: C3 Electrical


Ignition parts

Posted: 6/2/05 7:56pm Message 1 of 11
Lifetime MemberLifetime Member
Send PM
Canada
Joined: 8/6/2004
Posts: 533
Vette(s): Coupe 74 - 454 Drive it like you stole it!
I have 2 questions with 3 pictures, but it's all related to the ignition.
 
Tonight I wanted to replace the spark plugs, the distributor cap & rotor.  I bought the plugs (Autolite Platinum) at WalMart and the distributors part at the local ACDelco parts house.
 
My first mistake; I bought the parts without bringing the old ones with me for comparison.
 
So here's my problems :
1) the previous owner had some Accel spark plugs (see picture 1below). The problem is that I selected the Autolite using the "computer" for a 74 BB, but they are too long... the headers are in the way (picture 3), can't fit my socket (and a smaller socket doesn't make it all the way thru the plug).  Should I replace with what he had in ? I did not know they had shorter one's in the first place.  What would you guys recommend?
 
2) the distributor cap (ACDelco part D336X) and rotor (part D448X) are too big (picture 2).  The rotor's screws are a 1/4" outside the retaining plate and the cap wouldn't fit because of the valve you can see on top of the rotor. Do I have the wrong parts, or the whole distributor has been replaced in the past and now I have to find non ACDelco parts that will fit that ?  (I think it was Accel as well).
 
All comments are appreciated.
 
(And if you look at the pictures for all the details, you will see how much work I have ahead of me, which is way I will get my lifetime membership sometimes this month!)
 
 
 
(Edited to remove the big pictures.  You can still see them in my profile. 6/17/2005)
 
74-45438520.4583912037


SPONSOR AD:: (Our Sponsors help support C3VR)

Ignition parts

Posted: 6/2/05 9:50pm Message 2 of 11
Former Member
Send PM
Portland, TN - USA
Joined: 4/29/2003
Posts: 805
Vette(s): 1972 Coupe Anything, but Stock and more mods to come! SSBC Force 10 Brakes, 3.73, TH350, 355 CID, Rack and Pinion, Vette Brakes suspension front and rear.

One. the acell plugs are designed for headers, and are called short header plugs.  It appears you have angled plugs.  If so many of the headers are not designed for angle plugs, so the PO might have used the short plug to remedy the angle plug problem. 

Know way of knowing unless you know the part number of the headers to verify where they will work well with angle plug heads.

If you have an aftermarket distributor, you will need to find the part number and get an accel cap and rotor that matches the distributor.

Just a word of advice, do not assume that any Department store computer will be correct when it tells you the part numbers.  In most cases I have seen they are wrong.  Wrong, mainly because over the last 30 or so years our cars have been modified or replaced with something other then original parts.

You are correct that you should have taken an old spark plug and your cap and rotor with you to try and match up the parts.  While Walmart might be the cheap place to shop, your better off spending a little more and shopping at a good speedshop or a major auto parts store when it comes to our cars.

Here is something that everyone should do, but we tend to over look and that is to create a log book for our cars.  We have one in everyone of our project and engineering cars at holley.  The book contains a list of what has been modified and the part numbers to those parts, and what the part numbers are for replacement parts like rotors, caps, plugs, plug wires, etc.  It also contains a list of what products to use on the engine, like thermostat temperature, oil type, oil weight, coolant type, transfluid brand, transfluid type, brake fluid brand, brake fluid type, etc.  Then there is another sheet that keeps track of all repairs, tests, changes, and a column of anything that needs to be repaired or change.  Its also good to have if you ever decide to sell your car or if anyone else drives it, plus it saves you a lot of time at the parts store looking up parts all over again. 




Ignition parts

Posted: 6/2/05 10:39pm Message 3 of 11
Former Member
Send PM
sonoma, CA - USA
Joined: 8/9/2002
Posts: 784
Vette(s): 72 LT-1 AC coupe,69 l-36 coupe
because of the headers you might have to go under the car with a box end wrench to break the plugs loose and the use your fingers to get the plugs out, After Shark is right about the shorter plugs made for headers you might want to stick withe the same, BB's have angle plugs,the new plugs you have look like a hotter heat range than the originals, which make them longer, in 74 GM went to te HEI type distributor with a larger cap and rotor with the coil built into the cap, thats what the box on top of the cap is for, guessing they gave you one for a 74, by looking at the photo it looks like someone put an earlier point type dist. in with a external coil, can't tell if it's GM or after market for sure, look for "Delco Remy" somewhere on the dist., also looks like the plug end of the wire's were arching on the headers, might want to buy a set of wire's with heat resistent boots, might also help to bang in a little clearance with a small ballpeen hammer where the plug ends are close to the headers, at least 1/4" between the boots and header.anips38505.9474421296


Ignition parts

Posted: 6/3/05 7:40am Message 4 of 11
Lifetime MemberLifetime Member
Send PM
Canada
Joined: 8/6/2004
Posts: 533
Vette(s): Coupe 74 - 454 Drive it like you stole it!
It's hard to tell from the picture, but at the bottom, under the bunch of wires, there is a cylinder with the "Delco Remy" inscription on it and one wire connecting from it to the center of the distributor cap.
 
I have the heat resistent boots, and they appears to be in good condition.  I also have all the spacers so the wires don't touch the headers.  I think the black mark that you see, was a drop of oil on top of surface rust and I rubbed it with my fingers.
 
Okay, not a problem with the plugs, I can certainly find the same ones.  I'm still not clear on the distributor. The current distributor cap has the "sliding door" at the bottom, just like the picture in the Haynes manual.  I did not see a brandname or part number on it, but if I were to guess, I would think Accel as well, because of the color.
 
Great idea for the log book. The PO gave me all the receipts he could find, and I was keeping all of mines, but the log book of what I did, for what reason and when (including all part numbers) and maybe some pictures is a great idea.  I will get started on that.
 
The PO also told me all the brand/type of fluids he was using and I go for the same.  I will put that in the log as well.
 
Concerning the distributor cap/rotor, I will find the same for now since it really need a new one and try to educate myself about the reminder of the ignition system before I make any modification.
 
Thanks for the input.



Ignition parts

Posted: 6/3/05 10:05am Message 5 of 11
Lifetime MemberLifetime Member
Send PM
Canada
Joined: 8/6/2004
Posts: 533
Vette(s): Coupe 74 - 454 Drive it like you stole it!
Okay, finding the correct cap & rotor was easy; went back to ACDelco with my used part and 2 minutes later I walked out with the correct new one's!
 
Concerning the spark plugs, I found that I could use Accel 276S or Autolite AR135 to go around the header's problem.  My question is :
do I have to run all the exact same spark plugs all around, or the shorter one's only when the header is in the way?
 
I should be able to answer that myself by looking at the old one's, but I only took one out last night. Stupid me!
 



Ignition parts

Posted: 6/3/05 5:38pm Message 6 of 11
Lifetime MemberLifetime Member
Moderator
Send PM
BINGHAMTON, NY - USA
Joined: 7/19/2003
Posts: 3808
Vette(s): ......
That is a Delco Remy style distributer,the sliding metal door on the side of the cap,slides up and then you insert an allen wrench into a screw on the point set ,that is how you adjust the dwell setting on your points,28 to 32 degrees,that cylindrical item below the dist. is a condenser for noise suppression for the radio,supposed to knock down the static.at one time I believe there was a chrome cover over your distributer,that was insulated to knock down ignition noise,


C3VR Lifetime Member #93

Ignition parts

Posted: 6/3/05 7:36pm Message 7 of 11
Profile Pic
Lifetime MemberLifetime Member
Moderator
Send PM
CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!

The length of the external insulator is not the critical part.  What is most important is the heat range, resistance, tip, gap, and all interior components.

But there may be slight differences in the plugs.  Even if both are acceptable, the difference could create a inbalance in the engine operation.  I see no advantage to useing some of each.  I would stick with all one type.




Ignition parts

Posted: 6/5/05 4:26pm Message 8 of 11
Lifetime MemberLifetime Member
Send PM
Canada
Joined: 8/6/2004
Posts: 533
Vette(s): Coupe 74 - 454 Drive it like you stole it!
Update!
 
I replaced the spark plugs today with AR135 (autolite) , the distributor cap and the rotor.  (BTW, the sliding metal door is fixed on this one).
 
I was actually able to replace all the spak plugs from the top of the engine, with a BB, hedman headers and factory AC.  I don't have any skin left on my arms, but I was somehow able to reach!
 
I took it for a test drive right after. First thing I noticed, it now idles perfectly.  It used to die right away when I start the car or engage in reverse.  I would have to keep on pushing the accelerator for the next 30 to 45 seconds, else it would stall.  It now stays right on!
 
I'm still waiting for my timing light by the mail, so when I took it for a spin, I noticed a really rough acceleration and lack of power. I am assuming that the timing and dwell adjustment will fix that (knock on wood).
 
One other thing, my book says the gap should be .35, but the PO had them at .20. Don't know why!
 
The new plugs I have, have a short post that doesn't go over the electrode. The previous ones were Accell 276S, but I couldn't find them. They are considered racing plugs, but this is not what I do. Does it really make a big difference ?
 
 



Ignition parts

Posted: 6/5/05 7:08pm Message 9 of 11
Profile Pic
Lifetime MemberLifetime Member
Moderator
Send PM
CUYAHOGA FALLS, OH - USA
Joined: 12/2/2003
Posts: 6424
Vette(s): 1975 C3 Red, T-Tops, Black Interior. All I need is time and money! Getting there!
Plugs do in fact make a huge difference.  Resistance, heat ranges, tip design, and many other plug factors all have an effect.  And even when the application book says it's the right one, it may not be.  There are huge differences between plug mfgs. The best in one application is the worst for another.


Ignition parts

Posted: 6/17/05 11:08am Message 10 of 11
Lifetime MemberLifetime Member
Send PM
Canada
Joined: 8/6/2004
Posts: 533
Vette(s): Coupe 74 - 454 Drive it like you stole it!
One more question about tune-up;
 
I did not replaced the contact point in the distributor, as it looked allright to me; no burn/corrosion sign like there was in the distributor cap.
 
This is a visual inspection; how about the ignition coil; how to you know when to replace it.  Is the performance of the ignition coil somehow measurable ?
 
I finally received my "tune-up" kit by the mail; timing light and dwell/tach meter.  I will give it a shot for learning purpose, but still wondering if it's worth it or just go for an electronic system.
 



in Forum: C3 Electrical


SPONSOR AD: (Our Sponsors help support C3VR)