I'm new to this forum: hello.
I have a very nice '83 C.d. Ville (60K) and have just blown the head gasket on the 4100 engine.
This is not a cheap repair, yet, I really don't want to junk the car.
Perhaps the money might be better spent on a different engine.
My question: Is it realistic to replace the engine with something else? If so, what mills would you folks suggest?

You could probably go with the later 4.5l or 4.9l, most likely an easy swap, since they are essentially the same engine.

Thanks, Wes.
My biggest complaint about the car is that high speed acceleration is almost non-existent. It cruises great at 60 or 70, but, hit the gas and it just sits there. A beefier engine that could cure this problem would be ideal.

Sounds like its time for a 500V8 swap :D Thats what I'm doing :D

Mad'lac:
Thanks for the reply.
What engine would that be?

The 500 inch V8 from the 75-76 Cadillacs or the 70-76 Eldorados.
You can use the parts from the 77-82(maybe 83)RWD Cadillacs.

Charles K,
Welcome aboard!
Your in luck sir. The car you have will be an easy swap for any Olds V8 basically. There are virtually tons of parts available for the job too. The most common install is the 350 but a 307 or even a 403 will just drop in. As I recall, you'll probably have to swap the transmissions as well.
Unfortunately, a 4.5 or 4.9 will NOT work for this install since your car is a RWD longitudinal mount engine. The others will ONLY work for FWD installs.
FYI, The FWD 4.1 can easily be replaced by a 4.5/4.9 though.
Good luck ;)

Got it: thx!
I was just visiting:
http://remanufactured-engines.com/page11.htm
for some info. They seems to think staying with the 4100
is a good idea (I have my doubts) and say this:

"Although some of the HT's reputation is deserved, much of it is like having Shannon Dougherty or Sharon Stone for a girlfriend. Even though it has a short temper at certain times the design is so attractive you wouldn't trade it in for a more reliable Ricky Lake type engine. Basically, never ever let it run hot. With it's lightweight bi-metal construction it's junk in 60 seconds. R&R and resurface the intake manifold every 60 thousand miles, get 20-w-50 oil changes, run Slick 50 or equivalent and the average HT will go over two hundred thousand miles."

PUT THE OLDS MOTOR IN IT! THE HT4100 IS A P.O.S.....If those guys on that site like it so much, Let them buy it from you!

Charles K,
Those guys are TOTALLY wrong.
1. The HT4100 even running like new is a dog.
2. How can you guarantee that an engine that is SO prone to over-heating, won't over-heat?
3. Anybody that suggests using 20w-50 in a HT4100 doesn't know anything about the engine.
4. Anybody that suggests using Slick 50........don't get me started on Slick 50!!

Like I said, do the Olds engine. 307 if you just want a cheap, reliable ride, the 350 if you want to have some fun, the 403 if you want to build a sleeper.
Hey I forgot, you could also drop an Olds Diesel in it too ;)

Great advice: thanks much, guys!
Yeah, Kevin, when I got to the "Slick 50" part I knew something here wasn't right. I mean, I'm supposed to dump all this dough into a rebuilt 4100 and then pray to God that the water pump doesn't ever break, or I'll totally destroy my engine?
And it is a dog on the highway, which is embarrassing, because it's a highway car. It's tough to take a Nissan Sentra jumping in front of you doing 70 because the old brick can't deliver at that speed.
KC: on the rebuild site, the core rebate for the 4100 was the lowest of ANY other Cadoo mill (at $200.) Doesn't say much for the "Shannon Dougherty" of engines. And just what DOES he mean by saying that "the design is so attractive.." I've never heard that engine described that way ("Got an '83 Coupe... gee, I hope they gave ya the HT4100!")
One more question: will I have to fanagle an inspection sticker because of the emissions?

Depends on the emissions tests they have in Boston.Down here in Texas we don't have them test(yet). In Houston and Dallas I think they do and maybe El Paso.

Sharon Stone is old and past her prime, the 4100 is old, but it never had a prime.

The core value is the lowest 'cause the chances of actually getting a rebuildable HT4100 is somewhere between slim and none.
And don't worry about emmissions, your car will still be tested at '83 levels and that's no sweat to pass with today's technology, even with an Olds motor. If nothing else, you could just transplant an entire engine w/management system out of any full size GM car w/307 Olds and 4bbl carb. It will breeze through emmissions and then run FOREVER.

The design is about as attractive as Bela Abzug! The only thing nice about the HT4100 is........Oh forget it, There isn't anything attractive about it! Kat's right about the emissions test....Just do it right and you'll have nothing to worry about!

Originally posted by kcnewell
PUT THE OLDS MOTOR IN IT! THE HT4100 IS A P.O.S.....If those guys on that site like it so much, Let them buy it from you!

Exactlly! Don't make the same mistake I did. I replaced mine with another 4100 after the original went in my 85. I kicked myself for it afterwords. SBC or Olds. The Chevy if you want to make a sleeper out of it;)

Originally posted by Charles K
I'm new to this forum: hello.
I have a very nice '83 C.d. Ville (60K) and have just blown the head gasket on the 4100 engine.
This is not a cheap repair, yet, I really don't want to junk the car.
Perhaps the money might be better spent on a different engine.
My question: Is it realistic to replace the engine with something else? If so, what mills would you folks suggest?

What a bunch of BS about the 4100 i just spent the past hour reading the posts on the Northstar engines and all their blown head gasket problems in addition to other sensor,electrical,computor and mechanical issues. I have owned my 87' deville for 4 years now with almost 140k on the original engine and i have absolutley no complaints about the 4100.
Charles, find a good mechanic that knows Cadillac engines and replace both head gaskets and the water pump with a New pump not a rebuilt one and have the mechanic do a complete tune up and oil change and you will be all set. My 87' runs very well and has been well maintained, i am the 2nd owner of the car, i have used Castrol GTX 20W50 motor oil in it for 4 years, the engine has plenty of power and still runs like new. I would stay away from slick 50 but after your odometer hits 100k change to Castrol 20W50, and make sure you change your oil every 2000 miles and don't hot rod the engine and you will be fine, it's a Cadillac so treat it like one, not a chevy or an olds.

20w-50 is far TOO heavy for the HT4100. The engine in your car has survived "in spite" of the oil, not because of it.
In warmer climates, it may not be as big a deal but generally speaking, the HT4100 was "designed" for lighter weight oils and therefore the heavy oils will not provide the proper amount of "cold flow" to properly lubricate the engine.

Dear Sound Advantage,
Thanks for the reply.
My only issue is your claim that the 4100 "has plenty of power."
Even when the car was in tip-top shape, this was never the case.
This is a highway car, yet, at speed, it possesses no acceleration whatsoever. Even at 60mph, old Nissan Sentras would easily blast by me.

Plenty of power.....If you're not in a hurry?

Plenty of power if you're 80 years old and drive back and forth to bridge club, lol. Mine had about 160K when it went. The topend went first and the bottom end followed suit soon after. The engine is notorious for wearing out crank juornals also. Once I put the second one in it was adaqute I suposse. I'm glad yours has lasted as long as it has. I'm impressed, you probablly don't dog you engine as much as the rest of us did. But you can't help but dog these thing due to their sever lack of power. 135hp and 155lb ft in a 4500lbs car dosn't constitute plenty of power in my eyes. Especially when the 95 Honda Civic sitting next to me is pulling similar numbers.

I thought the HT4100 had 200ft lbs. tourqe?

man, the Olds 307 in my mothers '89 Brougham is incredibly slow, and that is 140hp and 255ft lbs. in a 4400lbs car, the only thing going for the engine is the tourqe, runs nice and the fact that it just never dies (car, for some reason loves to overheat, happend about 4-5 times in the last 5 years... maybe more, but still runs great) overall if your not looking for performance, the 307 is a real nice engine.

wait, my mothers '84 Sedan DeVille that she had before the Brougham had the HT4100 in it...... it had 34k miles on it (about 6 years ago) she had the car 4 months before she was in a serious head-on (other guy was 100% in the wrong) so it's not like that the engine really mattered at that point, what I will say though, if she never sold the Eagle 4wd wagon (heard they are nice, ours was a real pos) and got the Caddy, she wouldn't be alive right now.... guy was doing 100mph in a '94 Camery, she was stopped, he hit her around 60mph (cops estimate) the frame of the car was twised soo bad, the driver side headlights were inline with the center of the car..... she still is not able to work (among many other things)

sorry for the long story there, but that is why she is now driving another 18 1/2ft. yacht, and I just love Caddy which is why I got my DeVille

Actually Panther, we were both wrong. You were closer the n I was though. As per the Cadillac catolog,

1985 Deville, Fleetwood, Limo w 4.1L 125hp @ 4400RPM 190ft lbs @ 2200 RPM. Needless to say, stupid slow.

Originally posted by Charles K
Dear Sound Advantage,
Thanks for the reply.
My only issue is your claim that the 4100 "has plenty of power."
Even when the car was in tip-top shape, this was never the case.
This is a highway car, yet, at speed, it possesses no acceleration whatsoever. Even at 60mph, old Nissan Sentras would easily blast by me.

Charles,
My 87' is a small body Sedan deville, maybe your car is a big body car and that would explain the lack of acceleration, I have been driving Cadillac cars since the 60s, back when they had big blocks under the hood. My 87' runs like like a scalded dog, it's the first 4100 i have ever owned so i can't compare it to other ones but all i can say is i have never noticed a lack of power and i definately dont have any problems out running Nissan Sentras or any other rice burners on the highway. If i want to go HotRodding i grab the key's to my 77' Pontiac T/A and ride around spanking Mustangs and Camaros, but a Cadillac is not a race car guy's it's a luxury car so your suppose to drive them like luxury cars, it's not what you have it's what you take care of. My car was bought brand new by a female nurse, she kept the car garaged and had it serviced on a regular basis and didn't abuse the engine. I have heard that the 82' and 83' 4100s had cooling problems but Cadillac fixed the problem in the newer engines, mine never has run hot. Two years ago the alternator seized up and broke the serpentene belt climbing a hill cruising about 70 mph, i just kept on driving till i reached home about 7 miles away and it never overheated a bit. I honestly have a problem maintaining a speed of 65 mph on the highway, my car likes cruising right at 80 mph, don't ask me why but i have to let off the gas to slow it down quite often.

Mike

a Cadillac is not a race car

HA! You obviously never saw mine then;) . 600hp of Nitrous breathing, ground scrap'n fury:D .

The SYC RIDE :D (http://www.cardomain.com/member_pages/view_page.pl?page_id=210987)

I had an '85 Eldorado with the HT4100.....Not the biggest or the smallest car Cadillac ever built. It was however, One of the SLOWEST Cadillacs I've ever owned! If I went to Tahoe or Reno I'd be in the right lane with the pedal to the floor just to stay at the speed limit going up hill.....The car was probably the nicest Cadillac I've ever had as far as styling and comfort are concerned but it was definetly the worst engine I've ever seen in a Cadillac. They did in the last couple of incarnations of that engine make a number of changes that made it run and stay together better. They finally got it right with the 4.5/4.9 series of engines. I was leary of the 4.9 when I bought it because of my BAD experience with the 4.1 but the 4.9 has turned out to be a fantastic trouble free engine with more than enough power and exellent reliability.

Hello all,
There is a 2 mile long hill that goes west on I-64 in Indiana just accross the river from where i live, alot of cars end up on the right shoulder about midways up it especially in the summer months, they Over heat. My 87' Sedan Deville climbs that hill every time i go to my sisters house in Indiana, it doesnt loose any speed climbing it and i don't have to make it go, it just climbs that hill like nobody's business, the only thing i don't like is coming back down it as it's hard on the brakes! Maybe they did something to the 87' 4100s to give them better performance, just out of curiosity what kind of gas mileage were you guy's getting out of your 4100s ? i get 23 mpg on the highway and i always run super unleaded in the tank.


Mike

The FWD '85 Deville was actually quite peppy especially compared to the previous RWD model it replaced. The Eldo's I drove back then didn't seem TOO bad but for some reason I do recall them being slower than the Devilles.

'87 4.1L V8: 130hp @ 4200 RPM, 200 ft/lbs @ 2200 RPM. They got about 5 more HP and 10 more ft/lbs over what I previously posted. Other difference is your car weighs about 1200lbs less then the RWD models. As far as gas milage. If I remember right that little MPG gauge on the dash used to read about 13 around town and 19 on the highway.