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 #232203  by 300maximilien
 July 26th, 2010, 3:36 pm
kawnate31 wrote:Cool! What modifications exactly?? Because I might get it if its reasonable

pm user daytrepper he is an engine swap guru
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 #232219  by FIREM
 July 26th, 2010, 8:11 pm
#1

Daytrepper
Dont poke beehives!



Join Date: Jan 2005
Location: Raleigh, NC
Feedback: 15 / 100%

Year: 1998
Model: Dodge Intrepid
Color: Go-mango
Posts: 8,933




How To: Convert a 2002-2004 3.5HO Engine to Work in a 1998-2001 and vice versa

--------------------------------------------------------------------------------

Heres the list of items you will need to change on a 02-04 3.5HO, to make it work in a 98-01, or vice versa. This applies to 2.7 conversions, as well as 3.2-3.5 swaps. To do this properly, you will need either a good core 3.2 or 3.5 98-01 engine as a parts source, or buy everything used indiviually.

**This process also works when installing a 98-01 engine in a 02-04 vehicle, it is the same process with the exception of the EGR valve. You must remove the EGR valve and install a block off plug in the cylinder head hole, and install a non-egr plenum, all available from 02-04 engines.

If you are doing a 2.7 - 3.5 conversion, and using a 2002-2004 3.5 in a 1998-2001, you have to follow the instructions completely on the conversion itself, as well as these instructions.


You will need to change the following parts on the 02-04 engine with the same parts from a 98-01 engine, or vice versa, if installing a 98-01 into an 02-04:

1. Engine wiring harness
2. EGR valve & tubes (02-04 into 98-01 only, must be removed when going 98-01 into 02-04)
3. Intake plenum-- The plenums can be converted by swapping the following parts:
a. IAT sensor
b. Throttle body
c. MT valve
d. SRV valve actuator-- '04 has an electric one, 01 and older has vacuum, it will bolt right up in place of the electric no problem.
e. You would have to drill out the egr tube holes. They are there on the 04 plenum, just blocked off.
f. You would also have to drill out the vacuum port for the vacuum reservoir and cruise control servo, again the ports are there, just blocked off.
**If going 98-01 engine into 02-04 car, you must obtain an 02-04 plenum. The conversion requires EGR block off plates which are NLA.
4. Engine flywheel
5. SRV Valve Vacuum reservoir and hoses
6. Left camshaft sprocket. To change this, you will need to:
a. Buy the camshaft holding tool, OTC # 7999. 50$ cost roughly. It installs into the back of the camshaft and holds it in place so the camshaft sprocket can be installed in the proper position. Yes a timing belt can be changed without the tools, but it is critical that you use this tool when changing either of the sprockets. Not only is it next to impossible to keep the cam in the proper position, but you have to replace the bolts with new ones, and they have to be torqued to 75ft lbs, which the tools hold the cams in place again to make this possible. If you dont use these tools, you will seriously damage the valvetrain.
7. Alternator
8. Coolant Temperature Sensor

All that done, install it, plug it in, and start it up. Good luck.

Found this on the DI Site, From the master himself
 #232362  by kawnate31
 July 28th, 2010, 4:58 pm
well ive decided the most cost effective way to go with this is the rebuild route, the old engine in my car still ran great had good compression and had a good top end so im going to rebuild the bottom end, get the crank turned, new oil pump, rear main seal, oversized bearings and reuse my brand new water pump and timing belt from the engine in the car i estimate i should have around $400 in that compared to the $800+ everyones wanting for engines close to or above 100k miles :? hope this turns out well i cant wait to get it back on the road!!
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 #232368  by grayslater
 July 28th, 2010, 7:14 pm
kawnate31 wrote:well ive decided the most cost effective way to go with this is the rebuild route, the old engine in my car still ran great had good compression and had a good top end so im going to rebuild the bottom end, get the crank turned, new oil pump, rear main seal, oversized bearings and reuse my brand new water pump and timing belt from the engine in the car i estimate i should have around $400 in that compared to the $800+ everyones wanting for engines close to or above 100k miles :? hope this turns out well i cant wait to get it back on the road!!
Best of luck with that.
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 #232372  by FIREM
 July 28th, 2010, 7:58 pm
Be careful. Fried mains may have circulated some of the bearing material into other areas. Block should come all the way down for line bore. Rear main seal assembly was on national back order recently........
 #321023  by jaded13640
 November 10th, 2013, 2:20 pm
Firem, Your post says that you must remove the left camshaft sprocket. Are you saying the left sprocket on the left head or both left sprockets?

It's a dual overhead cam engine so it'll have two left cam sprokets. Unless you're saying the "left most" cam sprocket and in that case I assume you're saying left as in looking at the engine from in front of the car. Technically that would be the right head as in passenger side.

My guess is that it has something to do with the cam sensor. Is that the reason for swapping them? Is that the only sprocket that need be addressed?

I'm about to head out there and (CENSORED) the motor out of my 01 300. Next will be snatching the motor out of my 04 intrepid that got smashed to use in the 01 300. I'll start a new thread and post progress. Again, thanks.

Thanks much,

Wayne

Ps, GREAT info. I was under the impression that the motors were interchangable untouched. I was not aware of the minor differences. Thank you so much for posting this information.
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 #321037  by Bill Putney
 November 10th, 2013, 4:07 pm
jaded13640 wrote:Firem, Your post says that you must remove the left camshaft sprocket. Are you saying the left sprocket on the left head or both left sprockets?

It's a dual overhead cam engine so it'll have two left cam sprokets. Unless you're saying the "left most" cam sprocket and in that case I assume you're saying left as in looking at the engine from in front of the car. Technically that would be the right head as in passenger side...
A North American 300M would have a 3.5 engine, which is one camshaft per head. The 2.7 engine has two cams per head. Is the engine from your Trep a 3.2 or 2.7? If it's 2.7, the 3.5 sprocket will not fit the 2.7 - totally different engine. But if your Trep engine is 3.2, the 3.5 sprocket will work.

The convention in car circles is that. unless otherwise stated, left and right are relative to a person sitting in the driver's seat - so right side = passenger side, etc. Because not everyone knows this, I always try to say passenger side and driver's side rather than right and left.
 #321044  by jaded13640
 November 10th, 2013, 6:44 pm
Agreed on the left right thing. Assuming that's what FIREM meant then it's the drivers side cam sprocket. That's the one with the camshaft positioning sensor so that would make sense.

I think you're right, the 3.5 only has one cam per head. I was thinking it was a dual cam per head but again, I think you're right, only one cam per head. Yes, it's a 3.5 in both cars.

Thanks,

Wayne
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 #321052  by Bill Putney
 November 10th, 2013, 8:08 pm
jaded13640 wrote:...Yes, it's a 3.5 in both cars...
That's right - I forgot they did away with the 3.2 in 2002. After that, only 2.7 and 3.5's came in Intrepids and Concordes.
Thanks,

Wayne
You're welcome.
 #322079  by jaded13640
 December 2nd, 2013, 5:20 pm
I have a question about changing the left camshaft sprocket.

Why is it necessary? If it uses the same cam sensor on both motors...what is the difference between them and why does it need to be changed?

Thanks,

Wayne
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 #322083  by Bill Putney
 December 2nd, 2013, 6:07 pm
jaded13640 wrote:I have a question about changing the left camshaft sprocket.

Why is it necessary? If it uses the same cam sensor on both motors...what is the difference between them and why does it need to be changed?

Thanks,

Wayne
The hole pattern in the tone wheel that the position sensor reads were changed along with the firmware in the PCM that reads the patterns of the signal coming from the sensor.
 #322128  by jaded13640
 December 3rd, 2013, 12:51 pm
So you use the same camshaft positioning sensor but the wheel is different? Different number of holes?

The special tool required to retain the cam while changing the wheel, is it absolutely necessary? I've used two pairs of visegrips to hold cams in the past. Has anyone done that?

The write up says the bolt that holds the wheel must be replaced. Is it a one time use "torque to yield" bolt? If it's not a torque to yield bolt then I would think there'd be no problem reusing it. We reuse rod and main bolts, harmonic balancer bolts. What's your thoughts on that?

Thanks,

Wayne
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 #322129  by FIREM
 December 3rd, 2013, 1:25 pm
Sensor same but "windows" on cam tone wheel in different locations. There is a fair ammount of play between the cam and the tone wheel. I would not do the job without the tool (the other side I have used a work around) dur to the fact that cam position is critical to performance and emissions. Sure you culd get it to run, but not accuratly...
Bolt is in fact "torque to yield" however after inspection it "could" be reused if not necked down. Loctite if reused.
I would remove it by hand rather than with an air gun if you plan to reuse it.
 #322148  by jaded13640
 December 3rd, 2013, 6:36 pm
Ok, I guess I'll buy the tool. I've been a mechanic for a very long time and have always resisted special tools if at all possible. Typically I buy the damn thing and use it once and I know that's exactly what will happen in this case.

I'm kind of surprised that there ins't a keyway on the cam and sprocket for alignment. It just seems stupid to not.

Anyway, that's a bunch,

Wayne
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 #322150  by Bill Putney
 December 3rd, 2013, 8:18 pm
Most people here would agree with you that, in general, very seldom do you need the special tools that the manuals say you need. But this one is an exception to that.
jaded13640 wrote:...I'm kind of surprised that there ins't a keyway on the cam and sprocket for alignment. It just seems stupid to not...
It has a keyway of sorts - the tip of the camshaft is D-shaped, and the sprocket has a slightly larger D-shaped hole (I may have it backwards as to which part has the female and which has the male 'D' shape) that allows rotational adjustment between the sprocket and the camshaft, but limits the range of that adjustment. That way, tolerance stackups in the assembled engine can be adjusted out to optimize the cam timing for best running, emissions, and fuel economy.

I don't know which flywheel you planned on using - the M one or the one on the Intrepid engine - but the hole pattern on the flex plate is also different between pre-02 engines and '02 and up engines for the same reason - they changed the timing code in the PCM starting in '02. The earlier scheme is called SBEC, and the later one is called NGC, which stands for "Next Generation Controller". The way to tell the difference on the cam sprocket is a round hole on the SBEC sprocket, and a triangular hole on the NGC sprocket - at least on the 2.7 engine. I don't know if there is similar identifying marking on the 3.2/3.5 engine. (I got that info. from posts 7 thru 10 here: http://www.dodgeintrepid.net/showthread.php?t=211360)

So - make sure you use the flywheel from the M, not the one from the Trep.


EDIT: I see that Daytrepper's instructions that Bob posted do list the flywheel as a part that must stay with the car when mixing and matching pre-'02 and post-'01 stuff. But worth reiterating in case you missed that.