HT4100 4.1, 4.5, 4.9 Discussion, 4.1 Spun a cam bearing, in Cadillac Engine Technical Discussion; i pulled my manifold off to change liftrs becuase one was tapping, i thought it was collapsed. cilynder #1 lifters, ...
i pulled my manifold off to change liftrs becuase one was tapping, i thought it was collapsed. cilynder #1 lifters, between them was a cam bearing, i looked at all lifters, nice shiny, not carving nothing. Engine looks new also. So now i'm gonan pull the motor out AGAIN and do the cam bearings. i'm gonna have the cam checked, if its bad i'll put a new one in. I was told that cam bearings are common on caddy motors period. And i did notice about 6 moths ago that my oil PSI dropped 10 psi lower cold, and 2 psi lower warm. that is why my lifter was tapping on a hot start, not enough pressure, not enough oil to lifters. I'll have that engine on the ground in 45 minutes.
well 4.1's and 4.5's are really not that different, i can easily throw in a roller cam and lifters, but thats more money, my lifters show NO WEAR AT ALL and same with the cam, and inside looks pretty new and clean, no sludge AT ALL. But if i'm doing new bearings, gotta do new cam. i get parts cheap enough, and i'm doing all of the work. it would suck for most people because they'd take it to a "mechanic" that think they know what they are doing. that is why most of the 4.1 and 4.5 etc engines after head jobs and any other repairs don't run, those "school educated" don't know a ****ign thing they are doing or about the engine.
Edahall, tell us what you did to get the 4.9 working
OK, here is what you need to do to go from a 4.1 to a 4.9. First off, you'll need an adjustable FPR to dial in for the extra fuel requirements of a larger displacement engine. Aeromative makes one for an LT1 engine that also works for our engines. http://www.aeromotiveinc.com/products.php?prod=13
Use the heads from the 4.9 and bolt the intake manifold/TBI from the 4.1 to the 4.9. However, make sure that the coolant passages on the 4.1 intake manifold line up with the 4.9 heads. It may take some modifications with the grinding stone or epoxy to get it to line up.
This setup will definitely have more power than a 4.1 but will not have 200 hp like a MPFI 4.9. However, the extra torque is going to take a toll on the 440-T4 transmission. My recommendation is to install a Transgo shift correction package to beef up this transmission. It fixes a lot of the weaknesses these trannies had.
Yes, the tranny must be out to put in this kit. However, if you're going to put in another engine, you're already 90% there and you might as well put the tranny on the bench and freshen her up. And at the same time, it really is not that difficult to put in a rebuild kit and give it new clutches. I would definitely recommend putting in new clutches and sprags if the transmission has over 80k miles. Those are 2 very common failures on these transmissions. But once you get this all done with the shift correction package, you should have a tranny that is more bulletproof than even the 4T60E that the 4.9 was originally mated too.
well since i'm tired of investing money into the car, literally i am trying to sell it. I'm gonna fix the 4100, really the 4100is not a bad engine, i'm gonna throw in steel timing gears, reseal all gaskets (not the heads), and and do new cam bearings, cam, and lifters. inside looks very nice, lifters have no wear at all and neither does cam. And the tranny is a rebuild and i'm guessing it only has like 15k kilometers, not miles. I have my BMW waiting to be finished so the caddy ahs to go. But it lokos like i've been driving with the spun cam bearings for a while, and it was running smooth and still hauled ass. But my buddy is buying an 88 deville with 4.5 with around 272,000 kilometers so we might do the TBI 4.9 in that and beef up the tranny.
well i pulled everyting apart, NOTHING looks worn, it doesn't even have the nylon timing gears, i thought the 4100's had em, but not 4.5's, anyway, i had 3 different very experinced mechanics loko at it, they all told me to replace the one spun bearing and put her back together. I'm gonan do new timing chain and gears and new lifters. I going to have her running at the end of the week, because i can't stand the V6 2001 for dmustang, honestly biggest piece of shit i've ever driven, not comparable at all to my 25 year old BMW 6 series.
nonono, the stang is for sale, and its not mine, tis one of the cars we have for sale in the shop, i don't want a japanese 4 banger, and the cadillac needs to be sold in order for me to finish my BMW, then after that is done, i'm gonna buy a 4.9 caddy, prolly a 93 deville. I spent literally an hour looking around the 4.1 while its taken apart, i don't see anything different from any other V8 other than aluminum block and different design heads. And my 4.1 is pretty quick. A new timing chain, lifters and a bearing will freshen it up a little.
The whole time that "main bearing thump" was the cam smashin up and down. So, i'll make a vid of me putting the last few things in and firing it up the first time and take some pics of the engine.
Sounds good. 4.9s are great, but the injectors suck. They go after about 60-80k miles. It's really the engine's only weakness. That's one nice thing about the TBI 4.x engines: the injectors last forever.
Be careful with the 4T60E tranny that comes with the 4.9s, too. It has a lot to handle with all of that torque. If you drive it regularly, it'll last forever; if you push it a lot, it'll have a hard time making it past 130,000 miles.
Another thing that killed those trannies: many 4.9 owners are driving around with improperly adjusted TPS sensors, causing the car to "idle" at 25mph. This power brakes the transmission, thus destroying it.
You won't notice a misadjusted TPS on a 4.1 because it's not that powerful at idle, but on a 4.9, it'll cause a heck of a problem.
i think you'll be surprised by the 4.9's power. according to motor trend test figures, the 92 seville sts with the 4.9 engine was about 0.3 seconds quicker to 40 mph than the 93 sts with the 300hp northstar (which ran 0 to 60 in 6.5 seconds). so, really, up to about 40, the 4.9 is VERY fast. After that, it starts to run out of breath.