inspection troubles

[JoeyD]

What trouble would I run into by swapping a 12 Valve motor into a 98 GM that had a 6. 5? My truck does not do anything but the safety but that may change in the years to come. Is it legal if I used a motor from a early 98 like mine? These are my last details to figure out.

 

[Hutchew]

I'm not 100% positive........

but I understand that it is legal as long as you install an engine that is the same year or newer than the one you are replacing and you meet the emmisions specs for that replacement. I could, as usual, be wrong or misinformed, so shake the salt onto this reply.

 

[bmoeller]

It was a long time ago when I read something about that. If memory serves me, they said that you can stick a different engine in an old(er) vehicle as long as the engine meets the emission standards that were in palce at the time motor was built.

 

[JoeyD]

I will check with a shop that I use. I just wanted to be more informed before talking with them. Not to many shops that do diesel inspections close by.

 

[HoleshotHolset]

Presently, In MA... .



Anything diesel registered under "1-ton" GVW has no emissions requirements. "1-ton" and over has particulate only... . snap test now... . looking to doing dyno/etc. in the future.



If you can't get it through... let me know... . I have my connections. Heck... the guys I know would be awe-struck by the conversion... and wouldn't care about the safety/emissions issue.



Worry about making your 4L80-E and your OEM gauge cluster happy... I'll take care of the rest!



Matt

 

[JoeyD]

The trans I can get a stand alone computer for, the guages I was just going to use GM senders in the proper locations. Should work, what do you think?

I have my truck registered for 10k GVW, I never changed it from the last truck that was a 3500. I thought keeping it there would requir only a safety inspection not the other way.



I have a guy that will make the motor mounts when the time comes unless there is a unit I can buy. Know of any?

 

[HoleshotHolset]

I don't know about the gauges... . you'll probably need to keep the ECM and/or PCM from the original 6. 5 It gives feedback to the gauge cluster for idiot lights, tach, fuel level, oil pressure, voltage, coolant temp, speedo, etc. All of these parameters are fed from the sensors to the ECM/PCM and then on to the cluster.....



You'll have to fool the ECM into thinking the 12-valve has EGR, no more than 6. 5L boost levels, 8-cylinders, etc.



Since you have a '98 - it's OBDII - which means that its ECM is very sophisticated compared to older ECM's and is a lot harder to deal with... . and especially to fool it into thinking that everything is alright with a 6. 5L V8 diesel under the hood... when in reality it's a kickbutt 5. 9L Cummins I6.



I'm not saying that it can't be done, but it will be a big headache.



On second thought... .

Here's an idea - get brave for this test.



Get your truck rolling down a hill in neutral - kill the engine somehow, but keep the key on - so you can steer and keep the ECM/PCM alive. See if the speedo and so forth still operate. If all the gauges will work "key on engine off"... then you may be a lot closer than we both think to making all this work.



I hope this works out for you - as I have a '96 2-door 4x4 Tahoe in the family that would love a 12-valve 6BT!



Don't worry about the motor mounts... . that's the least of our worries at this point.



Matt

 

[JoeyD]

Matt, I still have some homework on the guages and what not. One reason I was thinking it will work is the guy on The Diesel Page did a article about converting a electronic 6. 5 to a mechanical 6. 5. The only touble was the check engine light was on but everything worked fine even the trans. The more I write this plan out the more things I add to the list.

 

[Evan A. Beck]

Just remove the check engine light from the dash. Simple as that.

 

[HoleshotHolset]

Or use electrical tape... .



Matt

 

[Prairie Dog]

Federally speaking, you cant change any emissions related equipment (unless it's C. A. R. B legal). That includes the eng, even if it's to a cleaner burning configuration.

Sorry to be the bearer.

 

[HoleshotHolset]

Here in MA... . the CARB rules don't necessarily apply.



Diesels under 1-ton GVW don't have emissions tests. Diesels over 1-ton only have a snap idle test for opacity. Even if they go for a dyno test in the future... we could make it pass since they are still only testing for opacity.



Matt

 

[JoeyD]

I thought as long as the engine is as new or newer than the vehicle it goes into it would be legal. Then it must pass the emissions requirement for the motor installed.

 

[HoleshotHolset]

How many inspectors have you seen that actually look at the engine data plate?



All they ask is this:



Engine model year, Engine manufacturer, engine displacement, engine horsepower (they also ask at what RPM this HP reading is from), exhaust diameter, # of exhaust pipes.



If you said '98... then that would be good enough for them.



If you wanted to make this thing CA or federally legal... . that's all you man, but I know how to make it legal and pass all inspections in MA.



Heck... I passed inspection with straight-piped exhaust... the inspectors thought it sounded cool!



Matt