I have a 69 Plymouth Roadrunner 383 that is hard to start when hot. The battery does not seem to have enough power to turn it over for 5-10 seconds. The battery is fully charged and is a Mopar 72 series battery with 525 CCA. In 1969 an optional 70 amp battery was available (standard on the 440 and 426 engines). I'm looking for a part number for this battery so I can see all the specifications on it. Hopefully the higher cranking amps will solve the problem. I'm not only looking for the original part number but I'd like the cross reference to the new Mopar battery equivalent.
Year (other): Plymouth
Model: Roadrunner 4 spd
My name isXXXXX you can hook up a hot jumper battery with jumper cables and get her to spin at the proper cranking speed the battery MAY be the issue. There are many things that can cause this condition above and beyond a weak or low initial cranking amps of the battery. Battery cables that are not big enough to carry the current needed when the engine is hot and under high compression can cause this. The cables may be compromised internally where you cannot see the cable wire itself. I had this situation more than once and cut the cable open after installing new cables and the problem was resolved. What I found was the GREEN corrosion on the copper wires that ran the fully length of the cable. The other thing you should consider is the condition of the starter. Are the brushes fairly new? Are the bushing snug enough to keep the starter armature from dragging on the inner field coils? Is the starter shimmed or spaced properly between the Bendix Drive and the ring gear or is it bottoming out on the ring gear so when the ring gear gets hot and expands it binds the drive to the ring? This will also create a high amperage draw. So the battery amp hour rating MAY be the problem but there are all these other possibilities that should be checked right along with making sure you have ample reserve storage power from the battery. Also, one other thing, what is the running voltage of the battery and charging system. It should be (engine running) 14.4 volts. If it is lower than that it should be it can keep the battery (any battery) charged at a mild state so when you need the additional amperage to spin the engine through until hot and high compression conditions.
So let me know what all you have checked and/or replaced in an effort to resolve this condition and then I can advise you from there.
HAve a Blessed & Productive Day !
I had an original roadrunner and had the same issue with it back in 1969. After driving the car and heating up the engine, it was hard to start. The car turned over slowly but you had to 'catch it' at first crank otherwise the battery wouldn't turn it over. I've fully charged this battery and then started the car easily. It's when the car is hot that the problem occurs (same problem that I had in 1969). The guage shows that the battery is being charged while driving after cold start. It is curious that there was an optional 70 amp battery back then (per the owner's manual) and that it was standard on the 440 and hem engines. I'm sure that this is the issue. Can you tell me the original part number and the current cross reference equivalent ?
Thanks very much for the great information you provided. I will do my Very Best to find the original part number of the original battery. But either way I think you have surely covered all the bases and you may be right, that it just needs more cranking amps when the 440 hemi is hot. I know I use to race with a friend that was running a Chrysler 440 wedge and he would have hot cranking issues from time to time, especially coming in for a pit stop. Remember the cylinder head and really the entire engine gets much hotter when it is shut off and the coolant is not flowing, before it cools back down at or below engine running temperature. I will do some research to see if I can find the original number so we can cross reference that number but there are many High Cranking Amp Batteries on the market that can solve this issue. I just wanted to jog you thoughts a little bit about other possibilities that can make starting it hot even harder. I do realize this has been a long term problem. Especially with the Chrysler Wedge and Hemi's. they are a beautiful engine and probably in my estimation one of the finest Big Block Engines ever designed and built. The Chrysler gear reduction starter was an attempt by Chrysler to over come some of these issues. So sit tight while I do some research for you. others may try to jump in and give their opinions but I want to makes sure I give you the exact and correct information.
I appreciate your patience while I do the research for you. One other thing (if you have one or could borrow one) would be to take a Volt meter and tell me exactly what the volts are running at the battery with the engine running. I just want to make sure that there is not a voltage problem as well. I have seen the dash guages not give a very accurate reading many times before. I have experienced this combined problem before with many engines and I want to help you completely solve the problem. Not just do a temporary fix. So if you can get me that voltage number it would be helpful but I will find the Mopar Battery Number for your as soon as possible and post it right here for you.
Hang in there Bud.
It appears that the Mopar Number for the Road Runner with the 440 Hemi was Mopar number(NNN) NNN-NNNN70 Amp battery and it was a group 27 battery that had the RED Caps on Top. Then (I am sure due to complaints about hard starting (probably though in house Service Bulletins) they provided a 80 amp battery Mopar Part Number(NNN) NNN-NNNN
I found this information at: http://books.google.com/books?id=DMo_5v 3i63AC&pg=PA241&lpg=PA241& amp;dq=OEM+1969+Roadrunner+440+Hemi+Mopar+original+battery+part+Number&source=bl&ots=yqoDQVpo7q&sig=Ug_FMOAILQhJ1gJStuUa1Ns4gzI&hl=en&sa=X&ei=90KUT-3-MMXm2QXq2_2HBQ&ved=0CFwQ6AEwAw#v=onepage&q&f=false
So I would say (without question) that you need a 80 Amp or higher battery for your Road runner. In the different brands of batteries (There are only 3 automotive battery manufacturers in the USA) you should get the highest Cold Cranking Amps you can find. If you so desire I can take a look at some of the Brands like Interstate, Die-Hard, Etc. and see what we can find for you UNLESS you want to try to locate a Mopar Battery. Just let me know which way you want to go and then I will help you accordingly.
I appreciate your patience while I did the research. Just let me know what else I can do to help resolve the problem and get the battery you want for your cool Road Runner. We all just love these Classic Cars. they were cool then and they are more cool today. :-)
I will wait for your response.
I think this is the 70 Amp Red Cap that the article talks about. Take a LOOK and let me know what you think:
Here are the specs on it:
Crank Amps (32 deg F) 960
Cold Crank (0 deg F) 775
Weight 62 lbs
I found this and some other original batteries at: http://www.ebay.com/sch/i.html?_nkw=mopar+batteries
And then here is the Mopar Group 24 Green Cap Battery:
And the specs on it:
I am quite sure there are other sources but this was the first one that popped up.
So I will just stand by and wait for your response.
Have a Blessed & Productive Day !
PS- I hope this is what you wanted.
Thank you for the research. Here's some additonal information that may be helpful before finalizing this question. My car has the 383 cu inch motor and the current battery is part # XXXXX with 525 CCA. The owners manual from 1969 states "An optional 70 amp battery is available from your dealer (standard equipment on 426 and 440 cu inch engines). I'm a bit worried that if you're recommending MORE than 70 amps that this might be too much for the electrical components (e,g, starter etc). Your thoughts?
Thanks for your ressponse. YOU NEVER CAN NEVER HAVE TO MANY AMPS IN RESERVE. THE ACCESSORIES, HEADLAMPS OR WHAT EVER THE COMPONET " WILL ONLY TAKE THE AMPS IT NEEDS" ! So you cannot hurt a vehicle by having to much storage in the battery. Remember it is just a container that holds amps so if any electrical device needs ampherage to function the reserve is there. This is an old rule of Thumb that I used when teaching Electronic/Electrical systems. " The Voltage is compared to a water hose that you hold your finger over the end and feel the pressure- The Ampherage is compared to the Volume of water that comes through the hose"
Maybe that will help you understand the ampherage vs voltage senario.
40+ years as a technical expert/Especially Corvettes
Thanks very much ........research and answers were very helpful.
You are more than welcome my Friend. If you would like to contact me directly in the future, just go to: http://www.justanswer.com/profile.aspx?PF=19741685&FID=0
You can save this address or bookmark it into you computer for future reference. Please use my name "Dale" in the question line so the question will come directly to me.Thanks for accepting my answers and HAVE FUN WITH THAT "COOL" ROAD RUNNER"Attachments are only available to registered users.Register Here
Attachments are only available to registered users.
Dale: I have information regarding Corvette parts. Please email me for further information. Gord XXXXX
If you could give me a website or some place to go other than an email address or phone number I would like to view the access you have. I am bound by an agreement not to communicate with customers here on J/A via email or phone. So unless you can give me a link to a site I am sort of stuck.
I just do NOT break the rules.
Provide a non J/A email address and I can explain furhter. Thanks XXXXX@XXXXXX.XXX
I am not allowed to do that. The computer blocked your email address. I could loose my position with the company by doing this. I am very sorry but I must abide by the rules of the Company. I can tell you that I live in Amarillo, Texas. That is the best I can do.
Question is. I have a good friend who just iherited hundreds of thousands of dollars worth of 'original' Corvette parts, vintage late 50's to early 70's ............ many still in the orginal carton. He would like to sell all of them as a bundle rather than try to sell each part piece by piece through e-Bay etc. I have the inventory of what he has. The question is ...... who do you recommend he contact in order to sell the parts?
First of all I would NOT put a middle man in the middle of putting the items up on E-bay. What I would do is pay a professional appraiser to inventory the items, and make a list of each item and what his approximate estimated value is for each item. I would add 20% to that figure or each item on sell them on Ebay or Craig's List. YOU CAN ALWAYS GO DOWN ON THE PRICE BUT NOT UP :-) An appraiser will cost some money to have the inventory priced out. But even I would have to have some time to give fair estimates on individual items. There could be a small piece in that inventory that could be worth $1,500.00 but if you do not have the items appraised you might sell it for $ 15.00.
So, my answer is to search and find a automotive appraiser that will go through the inventory (You can save some money by doing all the inventory tagging yourself) so that all the appraiser is going to have to do is to make the evaluations.
PS- DO NOT GIVE AWAY A GOLD MINE ! I ALSO DO NOT KNOW WHERE YOU AND THE PARTS ARE LOCATED.
I'm located in Ontario Canada, just north of Toronto. The parts have all been catalogued by NOS or LONG ISLAND. A value of 50% was then applied and the total amounts to $ 150,000. My friend does not want to get into selling the parts one at a time. He would prefer selling everything in one price. Your thoughts?
Put ad's in Corvette magazines or better yet go on line and find the Corvette clubs (There are 50 to a hundred of them US & Canada) and post the entire lot on those websites. Get the word around and the Corvette Buffs will spread the word like wild fire. Be ready for counter offers. I wish I could contact you directly but I want to honor my word and stay within the rules of J/A.
Have a Blessed & Productive Day!