Can the 300 HP be swapped with 275 HP motor?

6158 Views 31 Replies 8 Participants Last post by doug morra, Jan 29, 2004

jimg

Discussion Starter · Oct 25, 2003

Can the 300Hp be swaped with 275Hp motor?

Hi, I have a 97 Deville vin code 9(300HP)has spun rod bearing ,found a vin code y(275 HP) engine with 54K miles for $400. (It was in a wreck,and right side head has 1 mount boss broken (out of 3) .What exactly are the differances between the to engines? I have heard heads(dealer says heads are same part#) The cams,Cam timing,Computer, exhaust manifolds,and gear ratios. Can someone Please help me? thanks jim g

1 - 20 of 32 Posts

epanightmare

· #2 · Oct 25, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

jimg said:
Hi, I have a 97 Deville vin code 9(300HP)has spun rod bearing ,found a vin code y(275 HP) engine with 54K miles for $400. (It was in a wreck,and right side head has 1 mount boss broken (out of 3) .What exactly are the differances between the to engines? I have heard heads(dealer says heads are same part#) The cams,Cam timing,Computer, exhaust manifolds,and gear ratios. Can someone Please help me? thanks jim g

the difference between the to motors is just the cam profile and the computer program. A vin#Y motor will bolt in and run just the same as a vin#9 motor. the problem comes when you try to interchange vinY and vin9 transmissions because the final drive ratios are different.
I have done this swap before and no problems yet.

jimg

Discussion Starter · #3 · Oct 25, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

epanightmare said:
the difference between the to motors is just the cam profile and the computer program. A vin#Y motor will bolt in and run just the same as a vin#9 motor. the problem comes when you try to interchange vinY and vin9 transmissions because the final drive ratios are different.
I have done this swap before and no problems yet.

Thanks,for the quick response! By "cam profile" I assume you mean that cam lobes themselves for different? Would you suggest that swap out cams (my appear to be good 74k on old motor). Was there any notable proformance differance? Is there Anything special I need to do or replace before installing junkyard motor.(I'm selling car,but I don't want any trouble:removal and Install such pain). Thanks jim g

epanightmare

· #4 · Oct 25, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

jimg said:
Thanks,for the quick response! By "cam profile" I assume you mean that cam lobes themselves for different? Would you suggest that swap out cams (my appear to be good 74k on old motor). Was there any notable proformance differance? Is there Anything special I need to do or replace before installing junkyard motor.(I'm selling car,but I don't want any trouble:removal and Install such pain). Thanks jim g

You can change the cams if you want to but its not required. the motor will run just fine with the vinY cams but about 10-15 fewer HP. If you want to install the vin9 cams then the only speical tools you'll need are a pully puller/installer set and a tool to hold the cams in place when you reinstall the timing chains. I wouldn't worry about changing the cams if you are selling the car. you might notice the power differance but its likely that the puchacer will be more than happy the power output

jimg

Discussion Starter · #5 · Oct 25, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

epanightmare said:
You can change the cams if you want to but its not required. the motor will run just fine with the vinY cams but about 10-15 fewer HP. If you want to install the vin9 cams then the only speical tools you'll need are a pully puller/installer set and a tool to hold the cams in place when you reinstall the timing chains. I wouldn't worry about changing the cams if you are selling the car. you might notice the power differance but its likely that the puchacer will be more than happy the power output

Thanks Again for your help ! I also wondered about demand for parts for this engine. Heads,starters,etc price? thanks jim g

elwesso

· #6 · Oct 25, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

If youd like more information, this has been discussed IN DEPTH..... Please search.......

Most of the time though, you dont buy individual parts, rather when the engine goes its better just to replace it with a new one.........!

epanightmare

· #7 · Oct 25, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

jimg said:
Thanks Again for your help ! I also wondered about demand for parts for this engine. Heads,starters,etc price? thanks jim g

I don't know about prices for parts but i know you got a great deal on that motor. From what I've seen the complete engines usually sell for 1000 to 2500 dollars used depending on milage:banana::banana:

Katshot

· #8 · Oct 26, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

I've always wanted to do an experiment with using the lower geared transaxle and the lower HP (higher torque) engine. I think you'd end up with a nicer package in the end but..........

Oh and BTW, there's more involved in doing a cam swap on a Nothstar than just holding the cams. You'll need the tools for holding the chain tensioners too, and I's probably suggest the flywheel locking tool also.

jimg

Discussion Starter · #9 · Oct 26, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

Katshot said:
I've always wanted to do an experiment with using the lower geared transaxle and the lower HP (higher torque) engine. I think you'd end up with a nicer package in the end but..........

Oh and BTW, there's more involved in doing a cam swap on a Nothstar than just holding the cams. You'll need the tools for holding the chain tensioners too, and I's probably suggest the flywheel locking tool also.

Thanks so much ,for everyone's help! You all sure know your caddy's. So I know for next time

God forbid) When removing the engine/trans/subframe; what is the trick with the wiring? That seemed to be the biggest headache! I got the engine out ,but sure seems like there should be a better way,It took me about 13 hours ! What the deal with the plug at the firewall(passenger side),that's not a connector,do you have to remove interior pieces to undo. I know someone touched on it,but I didn't know the best method. thanks Everybody! jim g

Katshot

· #10 · Oct 26, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

If all you're doing is an engine R&R, you CAN do it in the car which makes it way easier unless you have a lift and subframe stand. The harness connectors you describe generally break apart by removing a screw in the center which holds them together.

jimg

Discussion Starter · #11 · Oct 26, 2003

Re: Can the 300Hp be swaped with 275Hp motor?

Katshot said:
If all you're doing is an engine R&R, you CAN do it in the car which makes it way easier unless you have a lift and subframe stand. The harness connectors you describe generally break apart by removing a screw in the center which holds them together.

According to the haynes manual(I know there not alway right) and 4 differant cadillac dealership mechanics that have removed and replaced engines; the only way to do this is from the bottom;and as an assembly. But I know there are usually tricks,so please elaborate. thanks jim g

zonie77

· #12 · Oct 26, 2003

The plate the wiring goes through is just a big grommet for the firewall. The screws let it loose and you pull the wires through from the computer (after you disconnect them of course).

zonie77

· #13 · Oct 26, 2003

I've pulled front wheel drive engins out the top so I will not argue with Katshot. If you are only swapping engines that might be easier but I the Caddy looks harder than the others I've done. The N* is the first I've dropped out the bottom and with the exception of the wiring it wasn't that bad.

zonie77

· #14 · Oct 26, 2003

To Jimg:
I ran across another thread of halcyon026 looking for a cam.

http://cadillacforums.com/forums/showthread.php?t=3673

Maybe you two can do a deal.

jimg

Discussion Starter · #15 · Nov 15, 2003

zonie77 said:
I've pulled front wheel drive engins out the top so I will not argue with Katshot. If you are only swapping engines that might be easier but I the Caddy looks harder than the others I've done. The N* is the first I've dropped out the bottom and with the exception of the wiring it wasn't that bad.

Hi, everyone! Just an update I have completed the engine installation of the 275 hp engine in place of the 300HP. My observations: # 1 Man that was a pain in the neck!!! I have installed well over 100 engines ,transmission in various imports/ american made cars, and I can say without question ,that was as Bad as it gets. (please respond if you have done 1996-1999 deville engine replacement and have done worse? I do about 20 cars a year ,That are in need of engine replacement/repair,burnt wiring harness,light wrecks ect. If there are cars that are worse please let me know! Yes, the two engines(vin code Y and 9 ) will exchange The only Differance I could visually see was the oil cooler ,on the 300Hp and althought the heads are same part no. the cams are differant. Other wise everything fit and ran great. thanks guys jim g Ps There is one other thing? I have a 4 feet long two wire connector(blue and yellow ) That come off of the main anti-lock brake harness (right next to main unit located in the front lower left engine compartment on 1997 concours models (traction control) Where does that connector go? I beleive it has to do with the traction control ,but I'm over 40 and my memory is bad , and I just can't remember where this wire came from ? Help thanks again jim g

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epanightmare

· #16 · Nov 16, 2003

jimg said:
Hi, everyone! Just an update I have completed the engine installation of the 275 hp engine in place of the 300HP. My observations: # 1 Man that was a pain in the neck!!! I have installed well over 100 engines ,transmission in various imports/ american made cars, and I can say without question ,that was as Bad as it gets. (please respond if you have done 1996-1999 deville engine replacement and have done worse? I do about 20 cars a year ,That are in need of engine replacement/repair,burnt wiring harness,light wrecks ect. If there are cars that are worse please let me know! Yes, the two engines(vin code Y and 9 ) will exchange The only Differance I could visually see was the oil cooler ,on the 300Hp and althought the heads are same part no. the cams are differant. Other wise everything fit and ran great. thanks guys jim g Ps There is one other thing? I have a 4 feet long two wire connector(blue and yellow ) That come off of the main anti-lock brake harness (right next to main unit located in the front lower left engine compartment on 1997 concours models (traction control) Where does that connector go? I beleive it has to do with the traction control ,but I'm over 40 and my memory is bad , and I just can't remember where this wire came from ? Help thanks again jim g

sounds like you didn't connect the harness to the driver side front wheel speed sensor hope that helps

....

jimg

Discussion Starter · #17 · Nov 16, 2003

epanightmare said:
sounds like you didn't connect the harness to the driver side front wheel speed sensor hope that helps ....

I wish that was it. I kept thinking the same thing. But the driver side and passenager side speed senors as well as senors the sense the control arm postion are connected. thanks jim g

Dubya

· #18 · Nov 18, 2003

so you just switched the motors, so you have a 275hp motor with the 3.71 geared transmission? if you go to sell it, that would be a plus. as soon as they hit the gas they'll feel torque like no other caddy!

details! stock computer? stock transmission? drove it yet?? feel faster off the line?

jimg

Discussion Starter · #19 · Nov 18, 2003

Dubya said:
so you just switched the motors, so you have a 275hp motor with the 3.71 geared transmission? if you go to sell it, that would be a plus. as soon as they hit the gas they'll feel torque like no other caddy!

details! stock computer? stock transmission? drove it yet?? feel faster off the line?

Yes,all stock 300hp except engine ,just had to change oil filter adaptor to accept oil cooler lines. Yes I have driven car several times ,and seems to have great pick-up for such a heavy car ,but I couldn't drive before ,so I have no basis of comparation. I am pleased with the preformance ,and the car is near mint with 74k on car and 54k on motor. But ,I bought the car to sell ,I need 8k . Thanks jim g

zonie77

· #20 · Nov 18, 2003

Just curious...did you pull it out the top or drop the cradle? Not sure from your posts.

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