I would think that the bigger engine would be more comfortable and not need more cooling to do the same job.
I noticed that more on newer engines.
Older big blocks were giving me more trouble with heat but technology has changed.
I don't know.
CK5
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Quadrasteer 8.1L Suburban tow rig
- Thread starter Blue85
- Start date
2003 Suburban 2500 Quadrasteer camper towing 8.1L 6.0L swap 4L80-E
I noticed that more on newer engines.
Older big blocks were giving me more trouble with heat but technology has changed.
I don't know.
I've concluded there were 2 different core supports. I can't find any part numbers on this rad, but the guy told me it was from an '03 Suburban. The triple lower radiator hose is a good indicator of that. Rockauto confirms they are different parts, but of course doesn't describe the differences. Yes, mine has 2 sets of lower mounts and upper mounts, but the 6.0 rad was using the WIDER set. So this setup must be common with an even smaller rad, for 5.3L, 4.8L or whatever, which means it's "non-HD" probably.
I'm expecting there's a HD core support that takes 6.0 and 8.1 radiators. There are no holes in this support that line up with the bigger shroud.
I think the external dimensions are the same, so I can add mounting features, but the support is Aluminum, which I can't weld. So riv nuts, maybe?
I'm going to be called crazy for this, but the offset in the shroud opening is not because the radiator is mounted off-center. It's because the engine is mounted off-center!
I'm expecting there's a HD core support that takes 6.0 and 8.1 radiators. There are no holes in this support that line up with the bigger shroud.
I think the external dimensions are the same, so I can add mounting features, but the support is Aluminum, which I can't weld. So riv nuts, maybe?
I'm going to be called crazy for this, but the offset in the shroud opening is not because the radiator is mounted off-center. It's because the engine is mounted off-center!
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Just look at the 8.1 frame mount brackets and see how the engine isn't centered in the frame. The motor mounts on these are the same Left and Right.
View attachment 336882
View attachment 336882
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Is the fan/water pump pulley centered?
Riv nuts can work, but this would be a great time to tell Heather you NEED a TIG welder. You know, to fix it correctly...
water pump is very close to crank centerline on both engines. Would need a stronger effort to confirm it's exact.
the top beam is a bolt-in, so I could just drop it off with markings on it for someone else to weld. But.....we're still talking steel nuts into aluminum.you NEED a TIG welder. You know, to fix it correctly...
The top beam I need is theoretically available, but not in stock anywhere. Are junkyards still open? Dunno. But being able to unbolt all this is pretty awesome.
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You should look for someone parting out an HD. Lots of people buying up these trucks for the engines and parting the rest to recoup some money. Craigslist, FB marketplace, eBay...
I've been searching around for the core support I need. Looks like GM1225171 went into basically any truck without 6.6L or 8.1L. I had thought anything "HD" got GM1225196, but I measured one from a 6.0L HD truck and got measurements from another guy and basically they are all the same as what I have. GM1225196 has top holes only for 8.1L and side holes only for 6.6L. The provisions to mount a 6.0 radiator are not there.
This is a composite picture I made from aftermarket parts photos. Could there be an OEM version with both sets of holes? Maybe, but I doubt it.
I'm yet to come across any 6.0-->8.1 swap where they actually went with a factory 8.1 radiator. Mostly they went with something else and eliminated the oil and transmission coolers. So I can't find anybody actually pointing out this difference in the core supports.
View attachment 337076
This is a composite picture I made from aftermarket parts photos. Could there be an OEM version with both sets of holes? Maybe, but I doubt it.
I'm yet to come across any 6.0-->8.1 swap where they actually went with a factory 8.1 radiator. Mostly they went with something else and eliminated the oil and transmission coolers. So I can't find anybody actually pointing out this difference in the core supports.
View attachment 337076
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If you look at the bulge where the top center shroud mounts are, that makes that exact location difficult to achieve with riv-nuts on the 6.0 top bar. But to be fair, the shroud could probably attach with plastic push pins.
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Scored a whole Duramax core support for $50. As I expected, the lower rad mount holes are also wider. The 6.0 rad width is missing, but the narrowest set is still there. Most importantly, the big rad fits like a glove and the overall height is identical.
A modified version of the plastic rad spacer would allow a 6.0 rad to fit in the bottom, but it wouldn't connect at the top, unless this mythical dual-hole-pattern top bar existed.
8.1/6.6L top, 6.0/5.3 bottom.
The narrowest set of holes are 31 1/4.
The 6.0 width holes are 37"
The 8.1L width holes are 41".
Body mount holes are 46 1/2.
These are all on center and approximate.
Edit: here's a partial shot of both factory top bars:
A modified version of the plastic rad spacer would allow a 6.0 rad to fit in the bottom, but it wouldn't connect at the top, unless this mythical dual-hole-pattern top bar existed.
8.1/6.6L top, 6.0/5.3 bottom.
The narrowest set of holes are 31 1/4.
The 6.0 width holes are 37"
The 8.1L width holes are 41".
Body mount holes are 46 1/2.
These are all on center and approximate.
Edit: here's a partial shot of both factory top bars:
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Hey I have an OE AC bracket you can have if you want it.
Here's the frame mount brackets. The DS (top) is very similar, but the PS has the BB mounting points 3" forward of the SB points. SB has the mounts right across from each other (basically centered under exhaust ports 3 & 4). BB has one mount under 3&5 and the other under 2&4.
So the front of the BB will be 2" forward of where the front of the SB was.
So the front of the BB will be 2" forward of where the front of the SB was.
No reason to be afraid here. Wiring is the easy part. I'm working on using the 2003 6.0L harness in the truck on the 2002 8.1L engine. Cam position, CLT, oil level and knock sensor connectors are all different. I'll get around the throttle body differences by using the 03 throttle body and swapping to the 03+ oil fill tube. Since the LQ4 has no EGR I can either tune it out or add all those wires. The 8.1L injector harness can be deleted since the LQ4 harness has those connectors integrated. Not sure where I'll find the coolant or knock connectors. Trying to avoid cutting the factory harness other than lengthening the crank connection.
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When Raylar says "just lengthen a few wires and go" they are exaggerating of course, but it would be closer to that if I wasn't mixing '01-'02 style with '03+. That would solve oil pressure and throttle, anyway. Perhaps those guys run without knock sensors?
Here's my initial plan:
Here's my initial plan:
Crank pushing backwards?
Greg thinks it could be welding from the starter motor current. If the crank was moving, the whole converter should push into the pump. If that bottomed out I'd have bigger problems. If the flexplate flexes, it seem the pilot is supposed to slide axially in that adapter, but in this state it wouldn't be able to.
Here's the pilot on the reman. Fits nice on the 8.1L.
Here's the pilot on the reman. Fits nice on the 8.1L.
