73SwingerBuild
Well-Known Member
Hi all.
This isn't A-body specific, but it is Mopar. I have a 1972 Roadrunner and I'm looking for some advice on a rebuild. And I could use to vent.
My Dad and I restored the car when I was younger and it's been on the road about 8 years now. It has a 400c.i. HP motor, fairly stock, 0.030 over with a stock cam, stock dual plane intake, mildly ported stock heads, and stock cast iron exhaust manifolds. It's pretty much restored to factory specs but performs very well.
Anyways, I had it out about 3 years ago and it started to overheat a bit when I threw the water pump belt on the highway. I noticed it shortly after but the temperature gauge was almost pegged. Nothing blew in terms of water jacket plugs or cooling system components, but the radiator cap did open up and purge the excess pressure/coolant through the overflow drain hose.
Since then, I've been noticing more and more issues. Not huge issues that make a rebuild necessary, but a lot of small issues that make one seem imminent. Examples:
1. There are definitely some issues with the carb. It's a stock Carter TQ that's been rebuilt a few times and I'm starting to think there's either a vacuum leak or perhaps I just don't know enough about them to keep it tuned properly. It runs fine at speed, but just won't stay idling.
2. Power steering box developed a leak at some point. This could be resolved by removing the box with the engine still in the car, but I believe most of the driver's side exhaust, steering, and the torsion bar needs to be removed to access it.
3. There was a small water leak down the passenger side of the block. I still haven't pinpointed where it is coming from, but it started occurring after the engine overheated on the highway. It seems to have subsided for the the past year or two, but sometimes it happens after a short drive around town.
4. The exhaust manifolds have both developed small leaks around where the flange meets the head. They both also leak where they connect to the exhaust, but this may just be due to the crappy head pipes that my Dad had the local exhaust shop put on the car. I repaired the driver's side exhaust manifold leak by putting a new gasket on, but the threads on the exhaust studs were terrible and I could only tighten it so much before I feared they may strip.
Moving forward, I feel like a good rebuild of the top end of the motor would help to eliminate any and all of these issues. I could also take the time to upgrade to a slightly more aggressive cam, possibly a new Street Demon carb (the new one that looks like the TQ reinvented), and possibly some TTI headers. I would be keeping all of the stock equipment obviously, but I really want to make the car more fun to drive without taking away from the value of the car (it's all numbers matching).
In addition to venting my thoughts, I'd also like opinions on whether i'd be better off leaving the motor in the car and removing all of the top end down to the deck, or if I should just pull the entire motor out and rebuild it on the engine stand. I hate working over fenders, but I know pulling the engine out involves pulling the transmission, radiator, and all of the plumbing associated with the transmission and HVAC system, all of which are perfect right where they are.
Thank you all for letting me vent. Any responses and opinions would be very welcome. I'm just losing patience with the car but I would rather keep it than sell it.
-Mike
This isn't A-body specific, but it is Mopar. I have a 1972 Roadrunner and I'm looking for some advice on a rebuild. And I could use to vent.
My Dad and I restored the car when I was younger and it's been on the road about 8 years now. It has a 400c.i. HP motor, fairly stock, 0.030 over with a stock cam, stock dual plane intake, mildly ported stock heads, and stock cast iron exhaust manifolds. It's pretty much restored to factory specs but performs very well.
Anyways, I had it out about 3 years ago and it started to overheat a bit when I threw the water pump belt on the highway. I noticed it shortly after but the temperature gauge was almost pegged. Nothing blew in terms of water jacket plugs or cooling system components, but the radiator cap did open up and purge the excess pressure/coolant through the overflow drain hose.
Since then, I've been noticing more and more issues. Not huge issues that make a rebuild necessary, but a lot of small issues that make one seem imminent. Examples:
1. There are definitely some issues with the carb. It's a stock Carter TQ that's been rebuilt a few times and I'm starting to think there's either a vacuum leak or perhaps I just don't know enough about them to keep it tuned properly. It runs fine at speed, but just won't stay idling.
2. Power steering box developed a leak at some point. This could be resolved by removing the box with the engine still in the car, but I believe most of the driver's side exhaust, steering, and the torsion bar needs to be removed to access it.
3. There was a small water leak down the passenger side of the block. I still haven't pinpointed where it is coming from, but it started occurring after the engine overheated on the highway. It seems to have subsided for the the past year or two, but sometimes it happens after a short drive around town.
4. The exhaust manifolds have both developed small leaks around where the flange meets the head. They both also leak where they connect to the exhaust, but this may just be due to the crappy head pipes that my Dad had the local exhaust shop put on the car. I repaired the driver's side exhaust manifold leak by putting a new gasket on, but the threads on the exhaust studs were terrible and I could only tighten it so much before I feared they may strip.
Moving forward, I feel like a good rebuild of the top end of the motor would help to eliminate any and all of these issues. I could also take the time to upgrade to a slightly more aggressive cam, possibly a new Street Demon carb (the new one that looks like the TQ reinvented), and possibly some TTI headers. I would be keeping all of the stock equipment obviously, but I really want to make the car more fun to drive without taking away from the value of the car (it's all numbers matching).
In addition to venting my thoughts, I'd also like opinions on whether i'd be better off leaving the motor in the car and removing all of the top end down to the deck, or if I should just pull the entire motor out and rebuild it on the engine stand. I hate working over fenders, but I know pulling the engine out involves pulling the transmission, radiator, and all of the plumbing associated with the transmission and HVAC system, all of which are perfect right where they are.
Thank you all for letting me vent. Any responses and opinions would be very welcome. I'm just losing patience with the car but I would rather keep it than sell it.
-Mike