H3 First Cat

[4speedfunk]

Stick build em! You are now officially a fabricator right?

 

[CaseyS]

Near solid motor mounts (urethane) are not fantastic with a paint shaker engine. Everything on the grill and bumper will rattle to hell.

 

[MaxPF]

one I believe. My original had one also.

CJ, Im willing to try it, if they suck I will take em off. Are they a fab job or a CNC type deal?

I'd suggest poly mounts over true solid mounts. Vibes for one, but also because solid mounts will attempt to make your engine block a structural member as the frame flexes around. I realize direct-replacement poly mounts are probably not available, so if you're gonna do some fabbing you can fab up mounts using poly spring bushings. Here's an example that crawler made for his LQ4 swap into his Jeep using spring bushings:

I've also been running poly spring bushing motor mounts on my Cummins ever since I originally swapped it in. Vibes are surprisingly low, and they haven't sagged or otherwise screwed up even with 1000lbs worth of motor on 'em. You gotta figure if a pair can support 1/4th of a vehicles weight they can hold en engine just fine. I recently re-did my motor mounts to allow better turbo drain clearance, but I reused the same poly bushings. Here's some piccies, just for possible ideas:

 

[4speedfunk]

Nice looking stuff. Poly would be the ticket for sure...maybe a tad more time consuming to fab. I would like to draw some up on CAD and laser cut some pieces to produce them. I'm not real crazy about stock H3 motor mounts. Next time you got the hood up, have somebody jump inside your H3 and power-brake the truck up to 1500 rpms (forward and reverse). Stand back and look at the motor...you won't believe how much the 5-cyl. moves around! I've even pulled my AirDoc tube off the intake before. More attempts by GM to make a fluffy Cadillac out of a Hummer.

Anybody driving a SASH3 without a real bumper, already has the "structural engine block" whether they realize it or not. There is at least one SASH3 driving around (who shall remain nameless), where the engine block is the only thing holding the frame rails in place. -LOL

 

[CaseyS]

Energy suspension 9.9488 is the isolator you need. You will need to trim about .006 off the inner sleeve to get it to fit in the perch.

The inner perch can be prepped by cleaning the small locator tabs on the inside of the perch and enlarging the bolt hole from 1/2" to 5/8"

This bushing fits in a 2.5" od 2.0" id dom tubing. I'll have to look up the length, just a tad more than 2.25" I think.

These are mighty stiff with my 4bt. I wish I could find the same insert in a rubber instead of poly.

 

[MaxPF]

Nice looking stuff. Poly would be the ticket for sure...maybe a tad more time consuming to fab. I would like to draw some up on CAD and laser cut some pieces to produce them. I'm not real crazy about stock H3 motor mounts. Next time you got the hood up, have somebody jump inside your H3 and power-brake the truck up to 1500 rpms (forward and reverse). Stand back and look at the motor...you won't believe how much the 5-cyl. moves around! I've even pulled my AirDoc tube off the intake before. More attempts by GM to make a fluffy Cadillac out of a Hummer.

Anybody driving a SASH3 without a real bumper, already has the "structural engine block" whether they realize it or not. There is at least one SASH3 driving around (who shall remain nameless), where the engine block is the only thing holding the frame rails in place. -LOL

No crossmember under the engine that ties near the frame-side motor mounts?

Energy suspension 9.9488 is the isolator you need. You will need to trim about .006 off the inner sleeve to get it to fit in the perch.

The inner perch can be prepped by cleaning the small locator tabs on the inside of the perch and enlarging the bolt hole from 1/2" to 5/8"

This bushing fits in a 2.5" od 2.0" id dom tubing. I'll have to look up the length, just a tad more than 2.25" I think.

These are mighty stiff with my 4bt. I wish I could find the same insert in a rubber instead of poly.

Double-edged sword. Rubber would eventually sag, while the poly will hold up pretty well. Have you thought about using the fluid-filled mounts? You could do a captive assembly with fluid mounts and poly bumps to control excess movement off-road.

 

[rascole]

You must use a cat here in awesome CA. Your computer will know that the cat is missing and you will get hit on your next check. The new smog test is a read only and no tail pipe BUT, a big fat BUTT, the test is more comprehensive then before. The voltage signals your O2 sensors send back are tight tolerances and will quickly be flagged. The list for CA legal manifolds is very small. Either stick with a new factory, they are better than people think, or pay an arm and a leg for an unproven one.

 

[06 H3]

I don't believe they are better then we think. Colorado guys have gutted them and dynoed it with 10-15hp increase using a stock header that's gutted. 20-30 hp just from a performance header.

Also I would pay an arm and a leg for an oem one...500-800 or pay 320 for a performance header that will give me more power.

 

[MaxPF]

Nice looking stuff. Poly would be the ticket for sure...maybe a tad more time consuming to fab. I would like to draw some up on CAD and laser cut some pieces to produce them. I'm not real crazy about stock H3 motor mounts.

I actually think Todds (crawlers) mounts are a better design than mine. So much more that I may redo mine AGAIN. His mounts put the pivot poing close to the engine block, whereas mine puts the pivot point way out on the frame mount. Because mine is a relatively long arm hanging off the engine i worry about how much torque is being applied to the engine bulkhead. I have this vision of that whole section of my engine block breaking out at the worst possible time. So, if you design some it would probably be a better idea to put the poly mount close to the block like Todds. What do you think?

 

[4speedfunk]

I really haven't even looked at the motor mount situation but, if its like everything else on the H3...the available space is going to drive the direction of the design. Basically, I think you'll have to get the poly sleeve in wherever it will fit. I doubt if there will be much of a choice on where to locate it.

No crossmember on my rig. The THORparts front bumper is the crossmember...out at the ends of the frame rails. Next is the transmission crossmember, back at the doors. Of course the motor also serves as a crossmember -LOL. The original bolt-in diff crossmember under the motor, goes away with the SAS and so does the welded-in rack & pinion crossmember. So you definitely remove a bunch of beef. After the chop...the oil pan is fully exposed and there is no room to add anything directly below it, due to the live front axle. However there is some room to add a small crossmember just behind the radiator...06H3 did this to his and I'm considering doing the same it to mine...just for piece of mind, if nothing else. I have 1/4" frame plates from the doors forward but, these are vertical and they don't do much to control side-to-side flexing. Like all 4x4's...the big issue is the steering box, and the stress it puts on the frame rails. I can say that the whole thing is pretty rigid, as long as you have a stout front bumper. I have not noticed any movement or frame flex on my rig, whatsoever. But Squeaky has proven the frame can move around quite a bit...especially if you frequently wring it out on giant boulders, and also if you run a stock front bumper.

The stock bumper is completely inadequate for being used as a crossmember. In fact...its completely inadequate as a bumper! Anybody doing serious rock-crawling should install a real bumper, if for no other reason than to keep the frame from twisting all over the place.

 

[4speedfunk]

Might be easier to adapt an "already made" motor mount....
http://www.ruffstuffspecialties.com...paign=Vehicle/General+Survey&utm_medium=email

 

[07Custom]

Nice looking stuff. Poly would be the ticket for sure...maybe a tad more time consuming to fab. I would like to draw some up on CAD and laser cut some pieces to produce them. I'm not real crazy about stock H3 motor mounts. Next time you got the hood up, have somebody jump inside your H3 and power-brake the truck up to 1500 rpms (forward and reverse). Stand back and look at the motor...you won't believe how much the 5-cyl. moves around! I've even pulled my AirDoc tube off the intake before. More attempts by GM to make a fluffy Cadillac out of a Hummer.

Anybody driving a SASH3 without a real bumper, already has the "structural engine block" whether they realize it or not. There is at least one SASH3 driving around (who shall remain nameless), where the engine block is the only thing holding the frame rails in place. -LOL

Nameless huh lol reporting in brotha ;-)

Albuquerque New Mexico and looking for a Grizzly!

 

[CaseyS]

You can remove the second main cat and only run the header cat without throwing any codes. Don't ask me how I know that.

 

[ABNTROOP]

 

[justin94tt]

I remember reading a while back that you could delete the first cat in the exhaust manifold and if you request PCM tune to turn that O2 sensor off so you won't thrown a code.

 

[MaxPF]

I really haven't even looked at the motor mount situation but, if its like everything else on the H3...the available space is going to drive the direction of the design. Basically, I think you'll have to get the poly sleeve in wherever it will fit. I doubt if there will be much of a choice on where to locate it.

No crossmember on my rig. The THORparts front bumper is the crossmember...out at the ends of the frame rails. Next is the transmission crossmember, back at the doors. Of course the motor also serves as a crossmember -LOL. The original bolt-in diff crossmember under the motor, goes away with the SAS and so does the welded-in rack & pinion crossmember. So you definitely remove a bunch of beef. After the chop...the oil pan is fully exposed and there is no room to add anything directly below it, due to the live front axle.

There's not even room for a tube crossmember tucked close to the pan? I'd think between the engine and the suspension mounted in that location the frame rails are being twisted all over the place...

 

[06 H3]

Once I have my tube bender I may look into it but honestly i think I am good now. Running a Thor parts bumper a crossmember and the frame is plated with 3/16 plate. I know the SAS h3 built by a shop in Utah is running a stock bumper no crossmembers no frame plating

 

[06 H3]

Wtf

 

[CaseyS]

Help me out. What are we looking at here? Is that the outlet flange or your new header? Is your frame twisted that much .

 

[06 H3]

bellhousing hitting the header. Some modifying I have to do.... :roll:

what else is new

 

[LagunaH1]

I dont know if I wanna go back to OEM because he said he has seen this before. So I am going to avoid stock if I can

So... why?

Your cat lasted this long, why wouldn't a replacement last equally long?

Edit: never mind, I didn't realize I was posting in an old thread

 

[06 H3]

Header is in and working. Here's a quick review

For the so cal guys. Hit the hill past calgrove by the 5/14 merger going southbound normally right before the hill I am doing 75 and drop it in 3rd to maintain speed and just lose speed and drop to 65 at the top this time was going 75 dropped it in 3rd it accelerated up the hill to 80 then lost some speed at the top the slowest I hit was 70 for a second then accelerated back up. Definitely a power increase!

I ditched the OEM due to price mainly

 

[chaos254]

What did you have to do make it fit?

 

[06 H3]

just hammer it in a tad to get past the bellhousing. I could trim the bellhousing because its more of a protrusion there but that seems sketchy.

If I was looking to get every possible pony and it was a race truck obviously hammering it in a tad would not be ideal but the power is still better then power and its not a race truck. It amazes me how most parts are interchangable with the colorado but some little stupid thing makes it a non direct swap. You usually have to adjust something.

I also have no CEL!

 

[4speedfunk]

Does it sound any different?