Distinguish a revised (2GB) 7 bolt from a 2GA 7 bolt?

[Insomniac13]

Hey, is there any way to distinguish a revised 7 bolt 4G63 from a 7 bolt that would be found in a 95-96 model? I'm looking to buy a used longblock but I want to buy a revised style one if I can. I know the 98/99 models had a different cam position sensor, but I read somewhere that the late 97 model year engines were the revised blocks as well, do they have the same 98 style cam position sensor? I'm looking for the engine with the split thrust bearings to prevent crankwalk.
Are there different markings or anything?

 

[synthetek]

All 97-99 have the same can angle sensor so you wouldn't be able to tell by what cam angle sensor it has. The only way to tell is to open it up and look at the bearings.

 

[donniekak]

What is the vin on the block?

 

[Insomniac13]

All 97-99 have the same can angle sensor so you wouldn't be able to tell by what cam angle sensor it has. The only way to tell is to open it up and look at the bearings.

That's what I was afraid of. Guess I'll have to look for one specifically out of a 98/99

What is the vin on the block?

I don't have the engine in front of me, I'm trying to see what to look for when I buy one. What would the difference be if it was a revised one?

 

[HX35GSX]

I don't have the engine in front of me, I'm trying to see what to look for when I buy one. What would the difference be if it was a revised one?

Look at the block number. a block number after UC7** should be updated.

 

[94awdcoupe]

split thrust bearing does not prevent crank walk. running a hardened crank does. I prefer and have been using one piece thrust blocks for ten years with nitrided cranks and no issues.

 

[Doubleot]

split thrust bearing does not prevent crank walk. running a hardened crank does. I prefer and have been using one piece thrust blocks for ten years with nitrided cranks and no issues.

If you want to get technical nothing can prevent crankwalk. The only variable that's controllable is making sure whoever is building it has the proper training and experience to build a motor. Any motor can walk.

 

[Rikolas]

split thrust bearing does not prevent crank walk. running a hardened crank does. I prefer and have been using one piece thrust blocks for ten years with nitrided cranks and no issues.

So the comparisons of the two different thrust bearings is just a myth? Even when one was worn and the other not?

 

[94awdcoupe]

If you want to get technical nothing can prevent crankwalk. The only variable that's controllable is making sure whoever is building it has the proper training and experience to build a motor. Any motor can walk.

yes its true. I have seen 6 bolts and evo 8 motors with crankwalk. I am just speaking from experience and not theory. I have built maybe 40 7 bolt blocks with nitrided cranks. none have crank walked.

take it or leave it. but I feel a hardened crank in a one peice thrust block will be 100 times more walk prone, than a soft stock 7 bolt crank in split thrust block. both style thrusts have same surface area, there is no technical reason why a split thrust is superior. there is however an economic reason. the split thrust bearing system is cheaper to produce.

 

[Rikolas]

My current 2gb was made in may 1997. Is there any reference to the month of which the switch happened?

 

[Insomniac13]

Look at the block number. a block number after UC7** should be updated.

Thanks!

If you want to get technical nothing can prevent crankwalk. The only variable that's controllable is making sure whoever is building it has the proper training and experience to build a motor. Any motor can walk.

Fair point, I guess I should say I'm trying to keep the chance to a minimum.

So the comparisons of the two different thrust bearings is just a myth? Even when one was worn and the other not?

The revised blocks had much lower rates of crankwalk, which is either due to the bearing design or the fact that from late 97 to 99 the tolerances on the rotating assembly were made much more precise.

My current 2gb was made in may 1997. Is there any reference to the month of which the switch happened?

I don't know a specific month, but I've read somewhere on here that the Spyder's got the revised block later than the GST's and GSX's (and their Eagle brothers), there were no (or very few) 97 Spyder's with the revised block, but more of a handful of hard tops of the same year that got it.

 

[Rikolas]

Oh okay. It still isn't a huge issue, I'll just be hopeful that nothing bad happens. But I'll have to give it a look to see what I have

 

[Insomniac13]

Yeah, crankwalk is way overhyped anyway, but since I'm looking for a new engine I figured I'd want this one, plus I have a 98 so it's almost an OCD type of thing