: Difference between VIN Y and VIN 9

01-22-08, 03:50 PM
Can Someone Tell Me The Differences In The 2 Engines From A 96 - 99 Eldorado Or Seville

01-22-08, 04:22 PM
Y runs around 275 advertised HP. 9 about 300. Cams and PCM/management tuning, but NOT a simple swap. Take a long read in the N* PCM tuning forum (many pages.....)

The Y torque comes in at a lower range than the 9. Y is suited for the traffic light set while 9 appeals to the long haul high speed driver.

01-22-08, 04:37 PM
Y engines have 275 hp and 300 tq. Also have a 3.11 final drive ratio. 9's have 300 hp, and 295 tq. Also have a 3.71 final drive.


01-22-08, 04:59 PM
In the 96 to 99 engines the Intake Cams are the only mechanical differences.

The tranmissions are different from a Y to a 9 application. The biggest part is the final drive gear ratio. 3.11 vs 3.71

The PCM program is different on many levels. Too much to go into

01-22-08, 04:59 PM
The "Y" engines will obviously deliver a little better mileage due to the lower final drive ratio.

01-23-08, 05:45 PM
The Intake Cams are higher lift in the 9, and the valve springs are stiffer for both intake and exhaust valves. As far as I can tell, the valves are identical for both 9 and Y.

01-23-08, 08:17 PM
The Intake Cams are higher lift in the 9, and the valve springs are stiffer for both intake and exhaust valves. As far as I can tell, the valves are identical for both 9 and Y.

The spring are the same except in 93 and maybe 94. after that they are the same

04-04-08, 11:22 AM
How can I identify wich of them is each? Where can I look for to know if a engine is from a VIN Y or a VIN 9 car?


04-04-08, 11:50 AM
Take a look at your VIN. The 8th character will be a 9 or a Y. The engine itself also has a "VIN derivative" stamped in a pad on the lower right front side of the block.
Otherwise, read the Northstar Performance threads, go back a month or so and find AJxtcman's posts on Northstar cam numbers. It's all in here, somewhere.

04-04-08, 03:40 PM
Thanks for the reply, I ask becouse a friend bought a 98 STS with a hard knock in the engine ( I think it could be a rod), and he found other 97 northstar engine and bought it for the STS, but we don't know anything about the vin of the donnor car, so, this is why I ask. We allready have the engine, and don't find any to identify this other engine. I also must say that when he bought this engine, we was thinking that all northstar engines were equals, less little changes over years.

I think you donīt need that I say that I am new in cadillacs. My other cars are a 91 Trans Am and a 73 Camaro.

04-04-08, 06:18 PM
If you have the right VIN, '97 & '98 should be compatible.

04-29-09, 06:10 PM
Quick question, would a Vin 9 1994 swap with a Vin 9 1999? Both are STS's

04-29-09, 07:13 PM
The 94 will have different heads, which will need some modification, and there's a bolt hole for the RH engine/trans mount that will be non-existent on the '94, and you will need to drill & tap a hole for the knock sensor between the #3 and #5 cylinder under the intake. I'm sure I could think of other little issues but you'd be better off starting with the correct year engine. It can be done though.

04-29-09, 09:11 PM
'94 is OBDI. '99 is OBDII.

04-29-09, 09:35 PM
Yes it is OBD1, but if you use the 99's intake plenum & TB, you've already taken care of most of the sensors. I believe the CKP/cam pos. sensors are the same from 93-99, and so is the crankshaft reluctor wheel. The only thing you would have to do is relocate the mounting for the knock sensor and use the '99's, because in 1996 the knock sensor & its location was revised. Oil level and pressure sensors I'm not 100% sure but they can easily be transferred.

The issue is the "cuts" in the intake ports. This would pose a serious vacuum leak if they weren't filled up prior to bolting down a 95-99 intake plenum. JB weld or something similar would do the trick, provided that what ever you use, would never break loose and fall into the ports.

04-30-09, 12:16 AM
Thanks for the info guys, i'll see if i can't find a 96+ OBEII Engine

04-30-09, 10:00 PM
reading some of these threads. interesting. i bought a 97 sts. had a cracked block . which i knew about. But the car it self is in great shape. 13000. no rust. bought another motor off of craigslist. didn't care if it was vin y or 9. i am just using the short block . Gonna put my heads & intake on the lower end. using all the sencers from my original motor. Did all the back ground chks. on the 2 types of motors. Seems they both share the same parts. as noted by rockauto parts. was told the motor i bought was a 97. got going on the assembly went the stud route for the heads. got the timing chains in form the original motor. all is going great. Jump the starter and turned the engine over. All sounded good. Putting the timing cover on from original motor BAM. it does't fit. so i start checking out the motor a little closer. See that the lower left hand side is made a little diff.Now i am just wondering way this small sectoin of the block is different. I have the cover from the motor i bought. It is different. then the one that was in the car . So i start looking for stamp #s . found the 4.6L Don't know how to tell what yr it might be. Gonna go ahead and use the cover that came with it. Anybody got any clues on this little jackal on tis thing. kinda looks like an ear. , but it juttisions toward the crankshaft timing gear. Thx for the read.

05-01-09, 01:49 AM
First of all, do you have the studs or did you order from me recently? The fastener machine shop I deal with is going to have the next batch ready in a few days.

Secondly, if the other motor you bought has a different timing cover, and yours is a '97, you have a 98-99 N*- they revised the cover to allow for a new engine mounting bolt.

Thirdly- where is the block cracked? If it's the #3 cylinder down the liner, it will help me confirm one of my suspicions.