How hard is it to find CAT 627E Scrapers with a 3406 for the rear engine?

[I AM IRONMAN]

I was told the 627E is a much more productive machine with the 3406 rather than a 3306 for the rear engine, so the hunt is on! Trying to put together a good fleet of push pulls without breaking the bank. Can anyone add some information about them? What Series would use them?
Thank you,
Iron Man

 

[Nige]

I would stand corrected on this but personally I have never seen a 627 of any series with a 3406 in the back.

 

[I AM IRONMAN]

Thanks for the reply Nige! I was told that the later model 627E had the 3406 in the rear. Referring back to my Cat Performance Handbook, it shows the 7CB Series has 330 HP for the Tractor and 225 HP for the Scraper end. The earlier Series had 225 HP for the Tractor and 225 HP for the Scraper.
Could it be that they went from the 3306 to the 3406 in the Tractor end? It looks like a substantial jump in HP. Maybe I should be looking for the 3406 in the Tractor to find what I am looking for?
Thanks again

 

[Nige]

I think you're looking at the info in not quite the correct way. If we're talking 627E the front engine has always been a 3406 but as you rightly point out the power was jacked up from 225 to 330 when the 7CG model came out in 1990. (7CB Series is the back end of a 627E, 7CG is the front end) The back end has always had a 3306 in it, the same basic engine as the 637E just different HP.

 

[Nige]

So as not to spread more confusion, what I meant to say above was "It's the same basic engine model as the rear engine of a 637E just set up to produce different HP"

 

[Shimmy1]

Nor can I find any 637E's with a 3406 in the back. Are there any push-pulls with a 3406 in the back?? I can't seem to find any.

 

[Shimmy1]

First scraper I can find with a big six in the back is a 657G and that's a C15.

 

[Nige]

First scraper I can find with a big six in the back is a 657G and that's a C15.

Which is to all intents and purposes the 21st-Century version of the 3406. There is an Emissions retrofit to install a 3406E in place of the original D343 in the rear end of 657B (53K-prefix) scrapers. The original front engine for the 68K-prefix 657B tractor was of course the "famed" D346, and the least said about those POS the better.

 

[kshansen]

The original front engine for the 68K-prefix 657B tractor was of course the "famed" D346, and the least said about those POS the better.

Then mention of the little brother D336 is probably off limits to? Any one ever figure out why the rods liked to wear the grooves in the crank? Or why the rods were made with that thin ridge on the side away from the other rod on the same journal? NO rely needed!

 

[I AM IRONMAN]

Thank you all for correcting me on this. I knew there were people on here with all the answers. It's no wonder I could not find any of the units with the 3406 in the rear.
Have a Merry Christmas and a Happy New Year!

 

[Shimmy1]

I have often wondered why it took the engine manufactures so long to give up on the V-style engines. They all did it, and they were all considered junk by more people than people that liked them. I know this is a bit off subject.

 

[Bluox]

Thanks for the reply Nige! I was told that the later model 627E had the 3406 in the rear. Referring back to my Cat Performance Handbook, it shows the 7CB Series has 330 HP for the Tractor and 225 HP for the Scraper end. The earlier Series had 225 HP for the Tractor and 225 HP for the Scraper.
Could it be that they went from the 3306 to the 3406 in the Tractor end? It looks like a substantial jump in HP. Maybe I should be looking for the 3406 in the Tractor to find what I am looking for?
Thanks again

The early 627E had a 3306 the later had a 3406 thus the difference in HP.
Bob

 

[JDOFMEMI]

I seem to be a day late to the party, but I believe all the 62X B model scraper tractors started with 3306 engines, then the later ones were bumped up to 3406 so they could get out of their own way.

I have never seen nor heard of a 3406 in the rear of either a 627 or a 637 of any model. I don't see the need for that much power in the rear, unless you just like buying tires.

 

[I AM IRONMAN]

Thank you to Heavy Equipment Forums and all of the Knowledgeable Members!

You cannot buy the kind of help and knowledge that is shown on The Heavy Equipment Forum!
Thanks for all your help! :notworthy
Merry Christmas and a Happy New Year!
:usa

 

[Oxbow]

Expanding on what Jerry mentioned: The introduction of the 3406 in the front while having the 3306 in the rear was fantastic in my opinion because the front tires would then tend to be the first to slip, and hence controlled by a decent operator. Having 3306's on both ends there was no way the operator could tell if the rear tires were slipping, and they would usually slip before the front tires; i.e. very hard on rear tires.

I do not believe I would want 3406's on both ends unless the rear engine was tuned way down, and at that point the 3306 is likely the more logical way to go.

 

[oregon96pd]

I have often wondered why it took the engine manufactures so long to give up on the V-style engines. They all did it, and they were all considered junk by more people than people that liked them. I know this is a bit off subject.

I'm gonna guess you've never been around large engines if you think they all gave up on them? :beatsme

 

[Shimmy1]

I'm gonna guess you've never been around large engines if you think they all gave up on them? :beatsme

I guess I should have been more clear. I know they still build quite a few of the larger variety. Engines that run mostly constant constant RPM. What I was referring to was the popularity of V-8's in the medium truck and construction equipment market. 9.0 Liter IH, 3208 and 3408 Cat, 8.2 Detroit, 555 and 903 Cummins. All fairly useless engines and all (with the exception of the 9.0 L IH, which the 444/powerstroke kind of replaced) now have inline 6's where these once were.

 

[oregon96pd]

3408 Cat, 903 Cummins.

Both very good engines, the others...not so much. I was pretty sure thats what you meant, and their still extremely popular in mobile equipment, its only the small stuff where inline engines are present.

 

[Shimmy1]

903 good??? Definitely not my opinion, but I've only had experience with the ones in Versatile tractors.

 

[Buckethead]

I seem to be a day late to the party, but I believe all the 62X B model scraper tractors started with 3306 engines, then the later ones were bumped up to 3406 so they could get out of their own way.

I have never seen nor heard of a 3406 in the rear of either a 627 or a 637 of any model. I don't see the need for that much power in the rear, unless you just like buying tires.

Expanding on what Jerry mentioned: The introduction of the 3406 in the front while having the 3306 in the rear was fantastic in my opinion because the front tires would then tend to be the first to slip, and hence controlled by a decent operator. Having 3306's on both ends there was no way the operator could tell if the rear tires were slipping, and they would usually slip before the front tires; i.e. very hard on rear tires.

I do not believe I would want 3406's on both ends unless the rear engine was tuned way down, and at that point the 3306 is likely the more logical way to go.

I agree with that. How much power do you need in back? Too much and you will be spinning tires like crazy.