Fixing vs. Buying a New Engine / 273

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MuuMuu101

MuuMuu101

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I've got a stock 273 that's running low compression in one of the cylinders. I don't think anything's been changed and it's still running a 2-bbl carb. When I had it at my mechanics a couple months ago, they said it was running at about 50-60 psi, I believe, while the others were at about 120-150 psi (can't recall exact numbers). I've noticed that the car seems to vibrate at idle whether in Park or Drive but not while the car is moving, so I'm assuming that's the main problem. If it is generally how much would it cost to fix or what do you think would need to be fixed? I heard a valve job could cost north of $300. At this point would it be worth it just to get a larger running engine (318, 340, 360)? I'm also in no rush as I drive the car once every 2-3 weeks for about 10 miles a day. It still works.

On another note, surfing CL this morning. I spotted a 340 that was running (had video of it in the car) and had 484 purple cam and Edelbrock Air Gap Intake for about $1600. Is that an aggressive cam? I understand 340 are generally more expensive than 360's since there are less of them. I'm looking more for a street engine and his car looked a little pro-stock. I believe he was putting a stroker in it and that's why it was coming out.

Thanks for all your help!
 
the tricky thing about going to a bigger engine is what rear end does it have?

if it has a 7 1/4 then that restricts you to a 318 or smaller ....a 360 and possibly a 340 would snap a 7 1/4 like a twig.

also what are you doing with the car?

if you are just cruising and don't mind stock specs ...then fixing that 273 should cost much I rebuilt a 318 to stock specs for around $550. and that was a lot of new parts but all to stock specs.
 
7 1/4 is definitely a weak rear, but with regular street duty it'll hold up to as much power as you can make. the only thing that'll break it is a heavy foot. Rebuild you the motor you want, be careful for now until you can either rebuild an 8 1/4 or go full on and build an 8 3/4
 
Totally forgot to mention. I currently have an open 7 1/4 rear end with 2.94 gears and 10" drums; however, I've got an A-body 8 3/4 with an open 489 cased 2.76 gears that needs shock plates and U-bolts. In the long run I'd like a corner carver or pro-touring type of car. Right now I'm cruising it because all I have is sbp 14" steelies and 205/70/14. I know once I go to a bigger engine, wheels and tires may have to go. I've also got a floor-shift stock 904 in there.

If I do swap the 273, I was thinking about still keeping it in the garage and using it in the future to practice or teach myself engine building. Make it a little mini-project/scavenger hunt for used performance parts sort of ordeal.

I guess the question is, "Is it worth putting the $300 or so into an engine that isn't that desirable?" I know for a fact I don't want the 273 to permanently reside in the Dart.
 
If that 340 runs good, and doesn't smoke, that's not a bad price. You can probably find a running 318 pretty cheap, but stock won't have much more power than you already have. 273's built right, can produce a lot of power. It's all in what you want, and $$$'s.
 
'73red-duster said:
If that 340 runs good, and doesn't smoke, that's not a bad price. You can probably find a running 318 pretty cheap, but stock won't have much more power than you already have. 273's built right, can produce a lot of power. It's all in what you want, and $$$'s.
Click to expand...

Seems like it runs nicely. Maybe it's a members car?


[ame]http://youtu.be/IqN600yXr5o[/ame]
 
Sounds pretty good, I'd buy it.
If your 273 as the adjustable rockers you can swap those to the 340 for better valve adjustment.
 
...there are enough free /6s floating around...you could do quick swap until you feel comfortable to move up...I should say that there is a lot more work that has to go into your car than just swapping out engine / rear end if you are moving up.....
 
grassy said:
...there are enough free /6s floating around...you could do quick swap until you feel comfortable to move up...I should say that there is a lot more work that has to go into your car than just swapping out engine / rear end if you are moving up.....
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I already have a 273 in the car, why would I need a slant? I'd probably upgrade the suspension at the same time I replace the 273.
 
opps..brain fart there...looked at your thread...hope you have deep pockets...

post lots of pictures..
 
grassy said:
opps..brain fart there...looked at your thread...hope you have deep pockets...

post lots of pictures..
Click to expand...

I hope my pockets are deep enough. Lol.

I'd probably ride around in it and store parts till I can do the swap in the summer when I have more free time.
 
1600 for ready to go 340 is a bargain. Ask for reciepts for parts and machine work, comp. test, time slips, etc. Check the prices on crate motors and you'll see 1600 is nothing. Is that comlete from carb to oil pan? How about other parts like headers, starter, alt., brackets? The more the better.
 
MuuMuu101 said:
I've got a stock 273 that's running low compression in one of the cylinders. I don't think anything's been changed and it's still running a 2-bbl carb. When I had it at my mechanics a couple months ago, they said it was running at about 50-60 psi, I believe, while the others were at about 120-150 psi (can't recall exact numbers). I've noticed that the car seems to vibrate at idle whether in Park or Drive but not while the car is moving, so I'm assuming that's the main problem. If it is generally how much would it cost to fix or what do you think would need to be fixed? I heard a valve job could cost north of $300. At this point would it be worth it just to get a larger running engine (318, 340, 360)? I'm also in no rush as I drive the car once every 2-3 weeks for about 10 miles a day. It still works.

On another note, surfing CL this morning. I spotted a 340 that was running (had video of it in the car) and had 484 purple cam and Edelbrock Air Gap Intake for about $1600. Is that an aggressive cam? I understand 340 are generally more expensive than 360's since there are less of them. I'm looking more for a street engine and his car looked a little pro-stock. I believe he was putting a stroker in it and that's why it was coming out.

Thanks for all your help!
Click to expand...

First, buy the the 340.
Second, just pull the head on the bad hole and just reman it. Might cost a whole 150-250 bucks.
 
I woudl say it depends on why the cylinder is low. A leak down test would tell you if it was rings, or a valve. Rings are expensive to address, a valve isn't. So assuming it's a valve, I'd go with Hebrews - buy Mad's 340 (he's a decent guy too - so you might be able to deal) and then determine what's wrong with yours a little further than saying one hole is weak.
 
The risk is that you may find more work in the 273 than you plan on so you'd be better off swapping engines.
You might be able to Find a good running parts car with a 318 or better a 360.
The 340 sounds like a good way to go too.
Might as well plan on the axle swap at the same time.
No reason to keep the 273 and there's some value in parting it out to pay for your upgrade.
 
MuuMuu101 said:
Totally forgot to mention. I currently have an open 7 1/4 rear end with 2.94 gears and 10" drums; however, I've got an A-body 8 3/4 with an open 489 cased 2.76 gears that needs shock plates and U-bolts. In the long run I'd like a corner carver or pro-touring type of car. Right now I'm cruising it because all I have is sbp 14" steelies and 205/70/14. I know once I go to a bigger engine, wheels and tires may have to go. I've also got a floor-shift stock 904 in there.

If I do swap the 273, I was thinking about still keeping it in the garage and using it in the future to practice or teach myself engine building. Make it a little mini-project/scavenger hunt for used performance parts sort of ordeal.

I guess the question is, "Is it worth putting the $300 or so into an engine that isn't that desirable?" I know for a fact I don't want the 273 to permanently reside in the Dart.
Click to expand...
with that being said grab that 340
 
I just went on a good little cruise. The problem is definitely worse on cold start. I actually didn't feel it so much while idling at lights. If anything there was slightly a bit more vibration as I initially apply pressure to the gas pedal.

And fyi, Mad Dart and I have talked a bit. We'll see what happens towards the end of the week.
 
So, a little bit of an update. I didn't end up getting Mad Dart's 340 as I was really unsure and busy with school that week so he sold it to someone else. However, I'm still sort of on the hunt for a new engine and am curious as to what I should look for. I'm looking for a 360, mostly for cost and ease of installation. I'd rather have a 3rd Gen Hemi or something else but you know how pricing and labor intensive that can get. I think a fairly stock engine should be fine (kind of want to keep costs on the lower side). I will most likely want to convert it to something that's carbureted as well (for simplicity and cost's sake). I may be wanting to add boost to it as well. That being said what kind of 360 engine should I be looking for? I believe the magnum engines came out in '92-ish. Would it be best to go with that or an LA engine? I see Magnum engines pop up occasionally for about $500 or so. I know I'm probably going to need a motor mount, intake, carb, air filter assembly, and oil pan to swap it into my Dart.
 
Unless you get a running magnum for free like I did, I think you may be well served to stick with an LA...you can adapt some of your parts from the 273-like the rockers as was mentioned. A stock magnum would certainly propel your A with ease, but you'd have to run some magnum specific stuff or buy adapters for nitnoid stuff...run a search though...there are probably at least a dozen regularly commenting members who run magnums
 
Go to junk yard get late 80s/early 90s LA 360 roller block out of a truck or van.
 
Depends on budget a good running 318 would be cheapest and easiest direct swap.
Magnum the best bang for the buck but even with buying one for $500 it probably cost a $1000 in parts to put it in. Plus the 5.9l gonna speed up the time frame of a brake and rear end upgrade.
 
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