: Who has raced with thier FWD HT4100?



caddeville
12-21-05, 01:36 AM
How many of you actually raced someone with your FWD HT4100?
My dad raced a mustang V6 and beat it, and he raced a NICE looking bmw 318ti and beat that too and that guy had a 5spd.
Once i start officially driving by myself, i will race my dads caddy and we'll see whos caddy is faster, my car has lots of engine mods! I have MSD EVERYTHING!!

I~LUV~Caddys8792
12-21-05, 02:01 AM
FWD HT4100 V. 1988 Town Car??? :hmm:

caddeville
12-21-05, 02:08 AM
The HT4100 isn't that slow in the FWD devilles, my dads caddy is figgin quick of the line, we easily passed an escalade on the highway and he was doin atleast 160km/h, the speed limiter doesn't work on my dads car, it does not slow down at all on its own. The 4100 sounds pretty damn sweet isn't all that slow.

SilverFleetwood85
12-21-05, 02:09 AM
That engine is too fragile to be used to race. It isn't a bad engine it just shouldn't be raced.

caddeville
12-21-05, 02:34 AM
What do you mean by that engine is too fragile, its a typical V8. If it is maintained properly, you shouldn't have a problem. If we too this car on a long Hot Summer day 5 hour uphill trip, this engine is flawless. I changed the spark plugs, wires, cap, and rotor on my dads car yesterday, last time plugs were changed was 8 years ago. I took them out, they looked like new. I changed mine also and they were completely black and my car has 94,000miles. My dads car has almost 200,000 miles on the engine and tranny.

SilverFleetwood85
12-21-05, 02:51 AM
What do you mean by that engine is too fragile, its a typical V8. If it is maintained properly, you shouldn't have a problem. If we too this car on a long Hot Summer day 5 hour uphill trip, this engine is flawless. I changed the spark plugs, wires, cap, and rotor on my dads car yesterday, last time plugs were changed was 8 years ago. I took them out, they looked like new. I changed mine also and they were completely black and my car has 94,000miles. My dads car has almost 200,000 miles on the engine and tranny.

Did your dad own the car from brand new? How many miles have you put on your Deville? If your dads car was previously owned how many miles did he put on it?

illumina
12-21-05, 03:03 AM
I have something for your HT4100 Cadillac...

And it ain't my '91 Seville either...:D

caddeville
12-21-05, 03:16 AM
Did your dad own the car from brand new? How many miles have you put on your Deville? If your dads car was previously owned how many miles did he put on it?
My dad is the second owner of his cadillac. He purchased it in 1997 with 95,000 miles, and it currently has 176,000 miles on it. The 4.1 has never been a problem, and always had regular maintenance. I haven't driven my car much, it isn't finished. I drove it to the shop and back a couple times. I still have to get my actual license to be able to drive by myself. I just drive my dads car for now. My car needs paintjob, and headliner. That will all be done in the summer when warm. My paintjob requires 3 coats of clear, metal flakes buid up alot.

SilverFleetwood85
12-21-05, 03:39 AM
That is a lot of miles, it proves what I always thought that the HT4100 engine is a pretty good engine. Do you know if that engine on your dads car was ever replaced before he got the car? The replacement HT4100 have improved gaskets and bearings, so that is why I am asking.

Still a motor with 176,000 miles (especially the HT4100) should not be raced, or held at high rpm for long periods of time, something is bound to fail with that kind of stress.

caddeville
12-21-05, 03:47 AM
That is a lot of miles, it proves what I always thought that the HT4100 engine is a pretty good engine. Do you know if that engine on your dads car was ever replaced before he got the car? The replacement HT4100 have improved gaskets and bearings, so that is why I am asking.

Still a motor with 176,000 miles (especially the HT4100) should not be raced, or held at high rpm for long periods of time, something is bound to fail with that kind of stress. The engine is factory, plus my dad is friends with the x-owner, and we have all of the service papers. We took this car on 4 different hot summer trips, and they were all long 5 hour uphill trips. The spark plugs were 8 years old wen i pulled them yesterday and they looked brand new, mine were black. This engine is very healthy, but has noisy lifters, mine also has louder noisy lifters. They knock wen warm, i put a stethoscope on the rocker arm bolt and it sounded like someone was smashinig the engine with a hammer at a steady beat. But it made that noise ever since purchase.

70eldo
12-21-05, 06:08 AM
I thought the 4.1 was the disgrace of Cadillac?
In the Classic groups we rather ignore that engine! As far as I know it's a POC if you look at it in terms of reliability.

http://www.ht4100.com/Logos/HT4100.jpg

I~LUV~Caddys8792
12-21-05, 11:30 AM
the HT4100 had chrome valve covers...thats cool :cool2:

1985 Cadillac Fleetwood (FWD): 3364 lbs
0-60: 11.7
1/4 mile: 18.2

1986 Cadillac Deville Touring Sedan: 3298 lbs
0-60: 12.0
1/4 mile: 18.6

1986 Cadillac Seville: 3371 lbs
0-60: 11.7
1/4 mile: 18.2

1985: 125 hp @ 4200rpm & 190 lb/ft @ 2200 rpm
1986: 130 hp @ 4200rpm & 200 lb/ft @ 2200 rpm

http://www.albeedigital.com/supercoupe/articles/0-60times.html
(source for 0-60 times)

1990 Lincoln Town Car: 3936 lbs
0-60 : 10.2
1/4 mile: 17.5

150 bhp @ 3200 rpm & 270 lb/ft @ 2000 rpm

I'm pretty sure a 5.0 Town Car would beat any stock HT4100 car

SilverFleetwood85
12-21-05, 05:19 PM
I thought the 4.1 was the disgrace of Cadillac?
In the Classic groups we rather ignore that engine! As far as I know it's a POC if you look at it in terms of reliability.

http://www.ht4100.com/Logos/HT4100.jpg

It wasn't a disgrace to cadillac at the time it was built. Cadillac needed to improve its MPG on all its cars so they used the 4100, and as a result the engine delivered the gas mileage the government and consumers wanted at the time. As I have said before, the engine wasn't bad it just requires you to keep up on maintainance.

I~LUV~Caddys8792
12-21-05, 05:22 PM
It seems like a rather fragile, high maintenance motor, in comparison to the good old cast iron block '70s monsters

SilverFleetwood85
12-21-05, 05:29 PM
It seems like a rather fragile, high maintenance motor, in comparison to the good old cast iron block '70s monsters

You are absolutely right, but the big cast iron block motors guzzled a lot of gas, which was what Cadillac in the early 80s did not want. By the way the chrome valve covers are really cool, my Grandma's 82 Seville has them.

The HT4100 engine is a very smooth engine so at least it was refined which went well with Cadillacs image.

I~LUV~Caddys8792
12-21-05, 05:49 PM
Yeah, it was a very smooth motor, and quite advanced for its time. I always liked how they called their EFI "Digital Fuel Injection" :) Thats something Cadillac has always done, made a simple name or acronym very complicated sounding! And I have always liked that :D

Night Wolf
12-22-05, 12:28 AM
caddeville..... I understand you are 15...

To try and be as nice as possible.... before you type various stuff that alot of us find humerous, search and read alot about this stuff first.

ben72227
12-22-05, 12:42 AM
Yeah;)

There's nothing wrong with the HT4100, it's just a sucky Cadillac engine. It was rushed into production after the COLLASAL failure of the V8-6-4. It clearly was never meant to be a Cadillac engine, and it wasn't until the Cadillac line got smaller in '86 that it was able to be a...decent engine. Thank god for the 4.9 and the N*:sneaky:

caddeville
12-22-05, 01:05 AM
Believe me rick, i know almost every little thing about the 4100, i've been searching these engines for almost 2 years and finally got all of my questions answered. There is nothing worng with this engine, all you have to do is read the labels. My dads 4100 has almost 170,000 miles on the original everything engine and tranny. And he doesn't usually drive it soft, but doesn't sqeal tires upon take off. The 4100 is pretty quick in the FWD uni-body cars. I also installed MSD EVERYTHING on my 4.1, very big difference in power when we took my car for a drive. The 4100 also was an experimental engine and shares almost the same block as a corvette.

I~LUV~Caddys8792
12-22-05, 01:19 AM
The 4100 also was an experimental engine and shares almost the same block as a corvette.
WTF?!?!?!?!
Give Me evidence please!


Even in the 3300lb "lightweight" 1985-86 devilles the HT4100 is a dog...noone would call a 11.7 0-60 fast.
Have you ever driven a 4.9 deVille? Thats a whole 3.5 seconds quicker to 60!

caddeville
12-22-05, 01:53 AM
What i meant to say was, the 4.x engines share the same design BLOCK only, nothing internal. The 4.9 is just bigger overall, and has Port Fuel Injection. It is obviously going to be alot faster with the increased size of everything inside. Cadillac made lots of modifications to the main internal parts on the 4.9 engine.

I~LUV~Caddys8792
12-22-05, 02:13 AM
the aluminum 4.1 shares the same block with the iron 5.7 Corvette???

Night Wolf
12-22-05, 02:19 AM
Believe me rick, i know almost every little thing about the 4100, i've been searching these engines for almost 2 years and finally got all of my questions answered. There is nothing worng with this engine, all you have to do is read the labels. My dads 4100 has almost 170,000 miles on the original everything engine and tranny. And he doesn't usually drive it soft, but doesn't sqeal tires upon take off.

Eh, I can already tell you have much to learn about the engine.

There are plenty wrong with the engine, yes, the 2nd gen had some issues worked out.... but the HT4100 is not a prized engine. *At the time* it was great... good gas mileage, did the job.... but the reliability and downright pathetic performance have made it an engine to avoid.

Read the labels? you mean add coolant supplement? Same goes for all 4.x and Northstar.

I can't make judgement about your dad's car.... but it is very rare that the HT4100 made it past even 100k miles without a problem.

Either way, *it is not a race car* Please, "race" and "HT4100" do not go hand in hand at all... I mean, unless you want to race GEO Metros, 4cylinder Jeep Wranglers, and 307 Broughams running on 6 cylinders, then yeah.... you can consider it a race.


The 4100 is pretty quick in the FWD uni-body cars. I also installed MSD EVERYTHING on my 4.1, very big difference in power when we took my car for a drive.

The HT4100 is still a joke in the FWD DeVille, it is just less of a joke then in the RWD big body... that was trying to make something happen (big body get good gas mileage) but using the wrong system (HT4100) and therefore failed.

130hp and 200ft-lbs of torque is not quick.... there is really no way around that....

I mean, hell, my 1989 Oldsmobile has a 3800 V6.... besides the fact that the 3800 is a far superior engine then the HT4100, it is 165hp and 220 ft-lbs torque. That car is decent for what it is, ran a 16.9s @ 78mph at the drag strip..... the HT4100 FWD DeVille would probably be about even with my '79 DeVille, maybe even slower.... given the time period, the gas crisis at hand, and the car it had to move, the '79 in stock form isn't bad...... in the smaller, much lighter FWD DeVille.... it is pretty bad.

by "MSD EVERYTHING" do you mean spark plugs, wires, dist. cap and rotor that you mentioned? Sorry, but that is just a tune up... if you added one of those MSD ignition boxes, then yeah... .but really, you would have to be stupid to do that on a stock HT4100... well, any HT4100.... because there would be NO gains at all, trust me, the stock HEI is completly capable of producing any spark that engine could possible need.


The 4100 also was an experimental engine and shares almost the same block as a corvette

Dubya Tee Eff?!?!?

That is the biggest load of crap I have heard from here in a LONG time... it clearly passes Toyota buying GM....I just hope you don't go and tell your other 15 y/o friends that, then they are like, "woha, man, dat shiiit iz off da hook yo"

Serisouly, if I even get started at going on about how that is simply not true, I'll be here all night because I would get carried away.... so I'll simply close with.... please, think before you type... and remember the #1 rule of internet forums....

The "SEARCH" function is your friend :)

Night Wolf
12-22-05, 02:31 AM
What i meant to say was, the 4.x engines share the same design BLOCK only, nothing internal. The 4.9 is just bigger overall, and has Port Fuel Injection. It is obviously going to be alot faster with the increased size of everything inside. Cadillac made lots of modifications to the main internal parts on the 4.9 engine.

Using this logic, I guess the HT4100 shares the same block DESIGN as EVERY V8.... I mean, eight cylinders in the Vee configuration, right?

Serisouly, there is nothing similar between the two.

HT4100 was bored out and became the 4.5 in 1988, in 1990 the 4.5 received Port Fuel Injection over Throttle Body Injection, in 1991 the 4.5 was stroked and became the 4.9.

Of course the Allante HT4100/4.5 are somewhat of a different animal, getting more power thru differnt intake manifolds, had a nice rollor rocker setup and some other goodies.

The main problems with the HT4100 is waterpump failure causing over heats which would warp the heads/block surface, and then the engine needs to be junked. Add to that a really crappy cam in the 1st gen (literally get worn down) and problems with head gaskets.... not to mention literally no power... and it was just a failure.

Atleast with the 4.5, the problems were fixed, the 4.5 is a very stout engine, 4.9 just adds more power.

illumina
12-22-05, 02:47 AM
Umm...Just to clear some things up on the HT4100, IT IS A DOG of an engine! I've had two of them, one was in an '86 FWD Deville, and she was a gutless wonder at that. Just to let you know, I still have the car, minus the engine, which when I pulled the block and took it apart, the block fell to the ground in two halves! The other HT4100 car I have now has a much better and more powerful 4.5 liter transplant in her, and she has much more power, and a broader power curve than the 4.1 liter that was in her before. But still, the car is not meant to be raced, because the power increase isn't going to make it so that I will be able to. She has just enough now to get ahead of the common 4 cylinder at a stoplight, nothing more.

As for performance, there is not whole lot that you can do for the 4.1 liter, because even if you should make an extra 30-plus horse power, the car the engine is attached to is going to be quite heavy and the performance won't be as noticable. Especially the RWD models, which were still land yachts in those days. And I do believe the cam specs are different, thus less broader of a power curve when compared to the later 4.5 and 4.9 liter siblings, and therefore not as responsive to mods like the MPFI engines that came out later.

As for the 'Vette comment, the only thing similar about the LSx series engines is that they have aluminum blocks with steel inserts, nothing more. No 4.whatever block has ever been used in a 'Vette made from GM that I'm aware of, and nobody is going to make an experimental 4.1 liter for a 'Vette. Period. And I should also mention that the LSx series engines are much better at that, even when compared to my beloved 4.9 liter.

caddeville
12-22-05, 02:48 AM
One of my dads friends, he is a mechanic and has a 1982 brougham. He knows absolutley everything about the 4.1 and has had 3 gm remans in that 82 deville and they all blew up within 60, 70, and 40,000 miles.. Now he just threw in a chevy 350. I did install the msd 6a ignition also, i did the plugs, wires, coil, ignition control module, cap, and rotor. My 4100 has plenty of power, and lets not forget that the weight of the car is almost 3500 pounds. My dads car has never had serious problems with the water pump. The tensioner was too old and was overtightening the belt and that caused the bearings on the waterpump. We used to change it every month until the rebuild POS waterpump finally siezed and broke the belt. The car did not over heat. All of the pumps were rebuilds, but my dad finally bought an ac delco brand new one and replaced the tensioner with a 4.5 pfi tensioner. All in all these are nice cars and are very comfortable to drive, if you will be a dumbass and race this car all the time, you will blow up your transmission. These cars are not meant to be used at a drag strip, i would never beat my car up like that. Sure, you can throw a nice exhaust, but that doesn't mean it will be a sports car. That is exactly what i meant when i said the 4.1 was similar to a vette block, they were both aluminum with steel sleeves and had a very similar design.

illumina
12-22-05, 03:01 AM
Rick, the most notoriuous issue with the 4.1 liter was not only the water pump, but the intake manifold gaskets, in which I've had one fail on my old '87. The reason behind this was that the engine design and the materials used and the gaskets used didn't quite agree with eachother from day one. When the 4.5 liter came out, more stringent torquing requirements were applied to help fix that problem.

Once the intake gasket blew or just developed a leak, water would then penetrate into the oil galleries and get in between the cam lobes and the lifters, soon wiping out the cams on the cars (which were weak in the first place). The 4.5 lilter engines improved this issue via the new torquing requirements and introduced the roller cam into the 4.x engine family.

caddeville
12-22-05, 03:09 AM
That is exactly what i have heard, you would also see coolant in the oil right? If the headgasket would blow, the car would blow white smoke and it would have a sweet smell to it.

illumina
12-22-05, 03:25 AM
That is exactly what i have heard, you would also see coolant in the oil right? If the headgasket would blow, the car would blow white smoke and it would have a sweet smell to it.

Concerning head gaskets, should the water get into the cylinder, then yes, you will see white-ish smoke from the tailpipes and the car will have one Hell of a miss. Other than that, an intake manifold gasket can cause the same issues should water get into the intake stream. With the head gaskets, should one develope a leak somewhere, you will notice a miss, followed by overheating, and then perhaps the engine will become water-locked along with white exhaust smoke. The tell-tail sign of a leaking head gasket can be seen from the coolant over-flow tank: while the engine is running, you'll notice little bubbles coming up from the bottom of the tank. Not good at all...

But, more than likely with the intake gasket leak, it will get into the oil at some point along the water passage areas of the two surfaces the gasket was meant to protect. Once it gets into the oil, you will notice the oil has a greyish, or milky tinting to it, and a dead-cylinder miss won't always be present until the water helps to destroy a cam lobe. Then it's a little too late for the basic help the engine will need.

Night Wolf
12-22-05, 04:17 AM
Thanks Illumina for clearing some of it up :)

Ah well, I'm outta here... I've got a plane to catch.... New York bound :)

ben72227
12-22-05, 01:32 PM
hee hee hee:lildevil:

Kid, the HT4100 was so bad...that they kept the 350 diesel around as an alternative. If that doesn't tell you something:sneaky: It wasn't until '86 when the entire Cadillac line was downsized that the HT4100 even became a FEASIBLE option. But hell, a HT4100 in a '82-'85 Eldo? I don't think so:canttalk: I remember it sucked so bad, that they even had to offer Buick's V6 in the Eldos, because it had more torque than the HT4100 and the exact same HP.

Big body Cadillacs were never meant to ride with an engine that puny.:(

I~LUV~Caddys8792
12-22-05, 07:53 PM
Have fun in NY bud! :)