2005 and 2006 gtx block differences

[actis]

i have a blown 2005 gtx limited 215 hp and i found a 2006 215 hp block but when i look at the block part numbers they are one number off.
the 2005 is 420890997 and the 2006 is 420890998. anyone know the differences between the two blocks and are they compatible? any changes from one model year to the other? can i use the 2006 block in the 2005 gtx? any insight would greatly be appreciated.

[Vern]

There are differences between the 2005 & 2006 engines, but you can bolt in any 4-tec block into any 4-tec ski, regardless of year as the basic blocks are similar. There are differences internally and some externally between the years though, so you cannot swap parts among years without doing some research. 2004 & 2005 are virtually identical and can be swapped, 2006 has some changes to oil pumps and other things, and 2007 up is different again. 2006 is kind of an orphan, unique to itself, ECUs and other parts are not compatible with any other year I don't think. There are other changes among model years too, including MPEM, etc, that others may be able talk about.

You can swap the entire complete 2006 engine into your ski, it will fit to motor mounts, exhaust, etc. But you need to also have the 2006 ECU/MPEM setup as there were changes in the engines that required a different ECU. You can not swap heads and other parts between these two years without some minor mods, so I guess the more important questions are: Are you swapping complete engines? Do you have the 2006 ECU?

[actis]

No I am not Going to swap the entire engine. My 2005 head is salvagable but the block is trash. So if I buy 2006 block casing, I'll need the ECM too then. That sucks. 2004 & 2005 block are my only choice for rebuild? Thanks for the info. Any one have a good 2004 or 2005 block?!

[Sea Dood]

No, you don't need the ECM from a 2006....Vern lead you down the wrong path, LOL.

Here are the two differences between the early and late blocks:

1. The early (2005 and older) blocks have a restrictor in the oil galley leading up to the head. The late(2006+) blocks don't have this restrictor.

2. The late (2006+) blocks have a large hole drilled behind the counterbalancer gear, because the vent system was moved from front to rear, and this allows blowby to flow into the rear section.

To use the 2006 block on your 2005 ski, all you need to do it buy a 2006+ rocker shaft and install it instead of your old rocker shaft. That is all you need to do.

[actis]

[s that the little check valve i see on the deck of the block near the timing chain about a inch from the head bolt hole? so i remove the restrictor and leave it open? whats different about the rocker shaft on the 06? that wouldn't be a problem because i intended to replace the rocker shaft and bolts as directed in the rebuild manual. Seadood, i hope you're right about this. was going to purchase the 2006 block until i saw vern's post. can anyone elaborate more on this? hate to fork out $600 bucks for a block that i would have to go buy a ecm and mpem. crap, thats the only two things i haven't had to replace on this ski!

[Sea Dood]

Yes, that check valve is near the timing chain opening is the restrictor assembly. But I don't know what you are saying. If you look at my post, I said the late 2006+ blocks do not have a restrictor. So why are you saying you will "remove the restrictor and leave it open"? (there is no restrictor to remove on a 2006 block....)

The 2005 head oiling system distributed low pressure oil evenly across the length of the head via cross-drilled passages. In 2006, they simplified it by removing the restrictor, and removing the cross drilling and feed the oil into the rocker with one small hole, versus three larger holes on the 2005. If you put a 2005 or older head on a 2006+ block, you simply need to use this 2006+ rocker shaft to have an equivalent setup to the 2006 head oiling system.

[actis]

my apologies, i was exhausted when i posted that. you're right, no need to remove because it's not there! DUH... can i use the 04 crank i bought ( my 05 was trashed from when it blew) i was reading the thread about the early and late cranks and what i got from that thread was you can use a 04 crank in a 06+ but the ignition timing will be off. but as long as you use the knock sensor the stock electronics will correct the 7-9 degrees the ignition timing is off?

[Sea Dood]

You are only using the 2006 block right? Keeping the 2005 PTO cover, right? Then there is nothing to worry about or consider. Again, if all you are doing is sticking a 2006 block into your 2005 ski, keeping everything else from the 2005, then you will be fine with a 2004 crank...

[Vern]

Thanks for the correction and additional info Sea Dood. Very helpful as usual.

[actis]

ok, good to hear Seadood. i'm new to this 4tec engine. everytime i think i've got it figured out, i read something that makes me second guess what i bought. when i read your early to late model crank thread, i thought i was in trouble! i will be using a 2004 crank, 2005 pto housing, 2005 head, 2006 block. just curious, what does it matter what year PTO cover i use? does it have anything to do with the crankshaft sensor? again, thanks for your knowledge.

[Sea Dood]

Yes, in 2006 they completely changed the position of the crank sensor in the PTO housing from about 12 oclock position to about 8 oclock. The reason they did this was because they changed the crankcase venting system from the front of the engine to the rear. This means that you should only use a 2006+ crank with a 2006+ PTO housing, and a 2005 and older crank with a 2005 and older PTO housing, to be 100% correct.

[actis]

ok, that makes sense, you the man Dood. thanks for all your help.

[cerhard16]

Not to bring up a 4 year old thread, but I'm in the same situation. I'm new to this forum, and new to 4-tecs. I have a 2005 RXT with a blown motor. I found a 2007 RXT long block that I was told would just marry up to 2005 parts, but am now second-guessing that. Will my 2005 parts will transfer over? What should I be worried about moving everything over (front/rear covers, intake, exhaust, electronics, etc)? I appreciate anyone's expertise. Thx!

[toxicgun]

Not to bring up a 4 year old thread, but I'm in the same situation. I'm new to this forum, and new to 4-tecs. I have a 2005 RXT with a blown motor. I found a 2007 RXT long block that I was told would just marry up to 2005 parts, but am now second-guessing that. Will my 2005 parts will transfer over? What should I be worried about moving everything over (front/rear covers, intake, exhaust, electronics, etc)? I appreciate anyone's expertise. Thx!

you can easily run that engine, best would be to use all the 05 pumps and electronics, you will need to clock the encoder two bolt directions and drill a new pin hole, you will also need to remove the plastic end piece off of the cam gear and metal washer.

[cerhard16]

Toxicgun...thx. I'm trying to use anything I can use from my '05 engine to reduce cost and get some benefits of the newer block/head. I am not familiar with these mods you are describing, I am glad to hear that it should work with my electronics, pumps/covers. Are you able to describe these changes I have to make? I appreciate any help I can get.