: 425 vs. 500..... hot-rodding.... need some opinions...



Night Wolf
07-07-04, 03:50 PM
Hello everyone... it has been a long time since I was last on here.... as everyone knows I have the '93 Coupe DeVille (my baby) and my 1989 Oldsmobile Delta 88 (winter/2nd car) I am going to see about being able to have both of those on the road.... gotta check it out next week....

...anyway, this topic has to do with my *other* car... I do not know if I told everyone about it.. I think I did... it is a 1979 Sedan DeVille d'Elegance...

Now, I got the car super-cheap becuase the guy thought it had a blown engine... it sat for 5 months and the wrist pins froze up... after driving 3miles to the gas station, the engine was quiet as ever....

Anyway, the car has 85k miles on it (origanal... I have some service recipts, origanal window sticker and 8-track tape still in shrink wrap) the whole drivetrain is solid too....

for what it is, the car has alot of power... it is not fast.. but it does have the power (2 30 foot lines of rubber on the ground proves that) but I want to make a sleeper out of this... something that you look at, and it looks like an old Cadillac, but will beat much faster, sportier cars.....

Origannaly I had it thought out, get a 500, get it rebuilt with performance in mind, throw some hot rod parts on it, and be done... well, I can get a complete 500 for $100, ready to be rebuilt.... we are very close friends with the owner of a machine shop, so labor will be very cheap, if anything.... I would get a stock rebuild done, but get the heads shaved down to bring compression up and a valve job, we would throw in a performance cam, the Edelbrock intake manifold, then exit with stock exhaust manifolds running to true dual exhaust system....

that *was* the plan... the way I figured it out, it would be under $1,000 total and I would have a '79 DeVille that would run a low-mid 14 in the 1/4.....

Well.... funds are tight for me right now.... well, not really tight, but I don't have $1,000 laying around..... plus, at 17, I am paying high insurance premiums, and I would like to have 2 cars insured (the Oldsmobile) and I will have to renew my insurnace plan next month, so I am trying to ave as as much cash as possible to pay off a big chunk of my insurance.... so I have 2 options....

hold the 500 plan off until the winter... hopefully if I work alot, and make money, I will not have much to spend it on over the winter (yeah right) and then build the 500....

OR.....

something I recently thought about.... build up my 425.... what's going for it? well, it would be the origanal engine in the car, only 85k miles.... the engines runs great and has no problems either.... although when I remove the oil cap and look into the valve covers, both the rocker arms and oil cap are sludgey.... oil changes probably were not done on time in its past life... but it dosn't seem to hold it back..... if I kept the 425, I would put the performance cam in, the edelbrock intake manifold (I heard those are the 2 biggest things holding the BB Cads back) get the carb rebuilt, keep the Qudra-jet, but get it rebuilt (it needs it either way) and then exit with the true dual exhaust.... *maybe* if we were in the mood, pull the heads and have then shaved down and do a valve job (can't do much with 8.2:1 compresson)

Now with this idea.... I wouldn't be able to beat a Mustang GT.... but I was thinking a 1/4 time of low 15... which is actually very respectable for any classic luxury car... not only that, but it would surprise plenty of people at both the track and on the street.... it would be a fun budget build too....

So, I was wondering how well a 425 would perform with the above mods... that would probabbly be $500-$600.... which is much more realistic... sure I woudln't be able to say I have 500 cubic inches under the hood, or 8.2L or the biggest production engine ever made... but I can just say it has the origanal Cadillac V8 :)

Well, anyone that knows my posts, knows I sure like to type alot... this post is no different... I hope it didn't scare anyone away :)

for the count, I don't street race... I go to the track... the best time I have got so far was a 15.9 @ 85mph in the '93 Coupe DeVille (4.9) that was before the tune-up, and I think the cat-conv is clogged (getting that fixed soon) I went with a Grand Am club, and my DeVille is even with a new Grand Am GT (175hp 3400 V6) but I am very much into cars, same with my father, and know alot about them... which is also why I know about the 1/4 times... and why I think some of those numbers are realistic for that car....

...So I guess to sum it up, basically, which would be better considering my budget, the 500 build up or the refresh on the 425.... and how does the 425 take to mods?

Night Wolf
07-07-04, 04:12 PM
after I got the '79 I took the '93 off the road, I drove the '79 around for about 2 weeks.... ran amazing... we did a very basic tune-up.... air filter, fuel filter, change the spark plugs (regular AC Delco) although the wires, cap + rotor were left alone (they are not origanal wires though) and I ran some carb cleaner.... although the carb does need to be rebuilt.... oh yeah, I tightened up the alternator belt becuase it was squeeking.. that freed up about 10 ponies (ok, jk :) ) Anyway, I put a total of 1k miles on the car... the biggest thing was the millage.... now I am not one to complain about gas prices.... but $50/weekto go 220 miles was getting bad (12mpg around town.... I think like 18 on the highway).... not only that, but I was driving the '79 while gas prices were at the peak... $2.33/gal for premium (what I run in all my cars) now it is about $2.23/gal for premium....

this car is just going to be a fun cruiser in the summer.... not a perfet restored car.. which is why I do not care that the crappy fake-wood contact paper on the door handels peeled off, the dash is cracked or that the millage sucks.... when I drive the '79 I drive for the power and enjoyment of what it is, and don't care at all about the gas that the big girl desires :)

Plus for gearing, right now it has the stock 2.28.... I would like to find a 2.78 posi for it.. but that will be difficult.... the TH400 is going to stay, it will get a shift kit though, and a tranny cooler.... I think that about covers it for now...

* actually the guy has 2 500's..... $100 each, they are both complete, although have been sitting in his warehouse for 15years, they are not turn-key and go... they need to be rebuilt... prefect cores.... once I decide what to do, I want to get the numbers from the engines and see which is the better choice to go with...

Night Wolf
07-08-04, 01:28 AM
:confused:

Imprl59
07-08-04, 05:58 PM
500. Wait another six months if you have to.

You can buy all the performance parts in the world for the existing engine and make it run like a scaled dog but every time you run it that little voice is going to be in the back of your head saying "yeah but what if I had done the 500?".

Trust me on this one... I've bought several cars that were almost what I wanted but not really. Like the '73 AND '74 SDV when I really wanted another '70. I ended up selling them both because of that little voice.

Steve B.

davesdeville
07-08-04, 06:14 PM
So... many... words...

It's a tough call. I've got a 78 Fleetwood with the 425, but my 425 is at 180k and not in good shape, so I'll go with a 500/472 if I do anything to this car performance wise. Your 425 is probably in good shape, which makes the choice tougher. At .6hp/ci, which is pretty much stock, you'll get 45 more hp with the 500. I'd probably save up and go with a 500. That way you can be sure the 500's in great condition before you start modifying it. The 425 has a minor issue with a weaker crank than the 500, but unless you're running lots of nitrous or something it's not a big deal. Speaking of which, you might consider nitrous as a mod later on, I wouldn't try more than a 125 shot on a 425, but I'd be comfortable with more like 150-200 on a 500.

barge master
07-08-04, 11:42 PM
For 100 bucks a pop, I'd buy both those 500s. They don't make them any more you know? Seriously though, they shaved a lot of weight off the 425 crank to lighten it. Plus they were just kinda de-tuned in general. You never know, just because those 500s have been sitting doesn't meen they need rebuilding. You may just need some valve seals and such. As long as they aren't full of sludge or rust, after all it's just a fun car right?

JTraik
07-09-04, 12:12 AM
for what it is, the car has alot of power... it is not fast.. but it does have the power (2 30 foot lines of rubber on the ground proves that) but I want to make a sleeper out of this... something that you look at, and it looks like an old Cadillac, but will beat much faster, sportier cars.....



Really? I wouldnt expect that from car with 180 HP.

Night Wolf
07-09-04, 12:20 AM
I have been thinking about it more...... and I know I really want the 500... just like how i first wanted to do the 500 build on a '75/'76 Fleetwood or DeVIlle (Coupe) but not only did I get a crazy deal on my '79, it the '75/'76 weigh an extra 1,000lbs+ then my already beefy '79.... with all that weight, it is just hard to make the thing go fast....

... something my father mentioned... which I will ask the guy next time, if he wants $100 each, maybe offer $150 for both and see what he says....

...my 425 runs great, I ran it today for a bit... and yesterday... when it sits for a week or so, it takes a little while to get her running... but it is carburated, and once it runs (besides the hesitation when cold.... carb needs rebuilding) it runs great....

... I am pretty sure the engines need rebuilding... the guy even said so... they have been sitting inside the warehouse for 15years, all the oil is probably drained, and for what it woudl cost me, a fresh rebuild with some tweaks would be the smart idea....

... right now I am thinking, save up my money for insurance (that way I can have the '93 and my Oldsmobile on the road) then this winter, when insurance isn't as big of a deal,and I have some cash laying around.... build up the 500.... then in the Spring, drop it in and have some fun....

plus, I would much rather say I have 500 cubic inches or 8.2L then 425 or 7.0.... its great to mess around with the ricer kids like that :D

67SupRFlyCoupe
07-09-04, 12:25 AM
Really? I wouldnt expect that from car with 180 HP.
Its not the HP its the torque

Night Wolf
07-09-04, 12:27 AM
this was when making a turn, I just stomped on the gas... although this time, I let off the gas right before the upshift into 2nd, so they COULD have been longer....

this is with a stock chocked engine, stock tranny stock car, 2.28 rear, no posi, and a carb that could use a rebuilding.... plus a full tank of gas (about 160lbs extra in the back)

*also in these pics, there are 2 or 3 seperate times from me...

http://www.gaownersclub.com/forum/attachment.php?postid=306861

http://www.gaownersclub.com/forum/attachment.php?postid=306870

http://www.gaownersclub.com/forum/attachment.php?postid=306874

http://www.gaownersclub.com/forum/attachment.php?postid=306878

in the pics it dosn't look long, but in person, it was....

JTraik
07-09-04, 12:29 AM
Its not the HP its the torque

Whens the last time you saw a dumptruck do a burnout?

Night Wolf
07-09-04, 12:42 AM
hmm, I guess it dosn't shoe the pics (I did the IMG tag) so you gotta click the link....

...anyway, after that, determined what she could do.... a few days latter I decided to keep my foot to the floor.... it was peg legged, I will say that much, but watching the speedo as it passed 50, I knew 2nd gear was coming, and thought to myself that it was the end of the fun.... to my surprise with the upshift into 2nd, not only did the right tire countinue to spin, but the left tire actually left rubber as well.... completly amazed I kept my floor planted to the floor.... the speedo was passing 80 (car was only moving 30mph?) and I knew 3rd was coming up.... with a 1:1 ratio in 3rd and a 2.28 out back, I knew that this had to be it... but when she shifted into 3rd, she kept laying rubber... I don't remember though it it finally didn't have the power, or I let off the gas at that time to slow down for the sharp blind turn coming up.... but I will say that in person, I couldn't believe how long it was... I think I counted 70 regular foot steps (not feet, foot steps) and the rubber was literally on the ground... I can prove that by taking about 4mintutes to circle around, park my car on the side of the road, get out, walk to the end of the lines with my camera, and as I was walking back taking a movie, I stepped on the rubber on the gorund, and my shoe started sticking to the ground... when I looked, the rubber on the ground was still in liquid form, and stuck to my shoe which picked up little pebbles and stuff....

this is also the reason why I need posi with the engine build up....

number 33 shows where the left tire spun when it shifted into 2nd... the only reason that I could come up with is that the engine RPM was closer to peak torque.... 320ft lbs at 2000rpm, and therefore sent a surge of power through the driveline...

my wheels are 15" spokes and I don't remember the brand of tires... nothing popular... but the tread isn't the best... actually that is why I didn't do that anymore.... when I get new tires I'll be sure to melt the old ones down somewhere.... :D

Night Wolf
07-09-04, 12:47 AM
Whens the last time you saw a dumptruck do a burnout?

when is the last time you saw a dumptruck haul 8,000lbs of gravel... uphill.... they *only* have 400hp.... a Corvette has 400hp... and you see Corvettes haul 8,000lbs of gravel around....oh wait.....never mind....

lux hauler
07-09-04, 12:52 AM
Whens the last time you saw a dumptruck do a burnout?When was the last time you seen a dump truck with car gears, car trans, car tires.........

Night Wolf
07-09-04, 12:56 AM
The $300 beast..... simply put, the guy thought the engine was blown (wasn't) and he was tired of seeing it around.... car is a d'Elegance (oh so comfortable) has decent options (no twilight sentinal and auto-load-level though) and becuase it was a FL. car, there is no rust (except for left back door where we think it was hit at one time... some paint peeled, and there is slight rust...)

when I got the car it had steelies on with worn, mis-matched tires, these nice (real) spoked wheels and white walls came on my mothers '89 Brougham.... she didn't like them, so they were istting under our deck for a few years, so I cleaned them up and put them on... made a world of a difference....

when I have more time, I'll post more about it (I don't believe I ever did here) but I have to get up in 5 hours to work for 8 hours...

JTraik
07-09-04, 01:07 AM
When was the last time you seen a dump truck with car gears, car trans, car tires.........

This is true. But still...the car only puts out 220 ftlbs....the pictures dont lie... i just dont believe it haha! That is a sick burnout tho!
:lildevil:

Night Wolf
07-09-04, 03:00 PM
I think you mean 320ft lbs ;)

cadillacdeville
07-09-04, 11:41 PM
If you want better power and fuel economy from the stock 425 it has to breath I just put a 14" edelbrock open faced breather along with the highflow muffler and I don't care what they say that 180hp rating is dead wrong my 77 can run with the best of them. If I was in you situation I would build up the 425 it's easy to work on and all it needs is a manifold intake and exahust a good carb and a good set of pipes and you'll get to the low 15's maby into the 14's.

Night Wolf
07-10-04, 12:44 AM
Well, this is what else I was thinking....

If I decided to buy some hi-po parts for the 425, such as the Edelbrock intake manifold, cam then the nice true dual exhaust etc.... it would be a cheap way to get more power....

THEN, since I woudln't be running the car like that for a long time, I could get the 500 rebuilt (I actually want to get both of them soon.... for the price, like people are saying... they are getting more rare) Actually, they might even be a 472... I think they are a 500 though... either way, the crank is the only difference....

but what I was thinking is, once the 500 is rebuilt and beefed up, I could swap the intake manifold over... there coudln't be much use on the cam at that point, so that could be swapped as well, and since they are pretty much the same engine, my nice custom dual exhaust should be able to bolt to the exhaust manifolds on the 500 as well....

... besides buying the engine, it would bring my inital cost wayyyy down.... honestly, if that car was running low 15 with those simple bolt-ons, I would be more then happy... I havn't taken it to the track yet (I want to before engine swap, or any work gets done, to get a before and after check) but if I was to guess, I would have to say the car would run 18seconds or so in the 1/4..... which is why shaving 3.5+ seconds off the time from those bolt-ons dosn't seem that easy....

...I guess I have decided that I would like to get the 500 and build it up... but for now, if I decide to get some of the performance parts... I would get the carb rebuilt, that can be used on the 500 too, the intake manifold can be used.... would it be safe to re-use the [new] cam? we are also going to hollow the cat out too.... damn thing is just so quiet for a big block V8...

and without getting into too much detail.... what are some basic upgrades with the 425/500 that would be a good star? I have the intake manifold and cam... I was going to keep the factory exhaust manifolds as I heard that it isn't worth the trouble of trying to find a decent set of headers that are designed for car use (not hot rod) when I go to get the 500 rebuilt, I'll let the machine shop guy do his tricks with the engine (he built up a 472, but converted it to a 500 and put it in his fathers '68 DeVille... stock intake manifold too.... says the thing just screams) the idea of this is to be low budget... so that when you look at the car, it will look like an old Cadillac, but beat a Mustang at the track :D

Night Wolf
07-10-04, 12:45 AM
oh, and I could care less about fuel econemy... plus I heard that people are getting 12-14mpg with a built 500 if geared correctly... I get 12mpg as of now, so I really woudln't be loosing anything...

Night Wolf
07-12-04, 02:47 AM
What would i have to do to get AC to work with the Edelbrock intake manifold? the current compressor (A-4?) will not bolt, but I heard that the 1980+ compressor will... any help?

barge master
07-13-04, 10:10 PM
I believe MTS has some sort of brackets to do that, Wolf. BTW that car is a lot nicer looking than you've made it sound. It's cool to see all you young dudes who like those cars. When I was 16 my 1st car was a 67 Lincoln coupe, I was the only young guy in town who drove a big tanker like that. I liked 'em then and I like 'em now. That's why I'm the Barge Master. Good luck. :cool:

lux hauler
07-13-04, 11:06 PM
What would i have to do to get AC to work with the Edelbrock intake manifold? the current compressor (A-4?) will not bolt, but I heard that the 1980+ compressor will... any help?I'm not sure you'll get the compressor to fit under the hood with that intake. Might want to do some measuring.....the carb and intake will be close too. The Edelbrock is about three inches taller than the stock intake.

Night Wolf
07-14-04, 01:40 PM
IIRC from an e-mail I sent, Bruce (Ultra Slow on the board) used his stock compressor.... I think in 1980 they changed it, he said that is fit without a problem and works great... so all I would have to do is get the 1980 style compressor and hook it into the system? it is compatible with everything else?

as of now, the AC dosn't work... out of freon, so we are going to switch it over to R-134A... but if I need to change the compressor, it'll just wait...

http://www.mcsmk8.com/80CAD-500/MAVICA.HTM

TorqueInc
07-16-04, 09:15 PM
I would not waste my time hotrodding a 425 for what your doing
the 425 rebuilt with good parts is great for mileage and towing but not for motivating a land barge
do at least a 472 with about 9:1 compression and youll have more than enough power to get yourself in trouble
also.....do a set of headers youll thank yourself in the long run IMO