Chassis Build Up & Design

looks good, i have a spare one of those if you ever need it

looks good, i have a spare one of those if you ever need it

I thought you might.  Could be a useful kit to sell, but maybe not if everyone goes with a cooler of some sort.

I've had a few things progressing slowly with this lad.  More progress on the harness.  Passenger side of the engine and the transmission are mostly sorted through.  I also picked up a standard cab from a pickup last night.  It will be getting cut down to just the firewall and floor to help mockup the engine bay and wiring inside and out.  Will be a lot easier to pull on and off the frame than a full Blazer body.  With a pair of fenders and a rad support I'll have the entire engine bay mocked up for use now and in the future.

This organization makes finding the terminals and seals a breeze


IMG_2993 by TheHarley, on Flickr


IMG_3001 by TheHarley, on Flickr


IMG_2994 by TheHarley, on Flickr


IMG_2995 by TheHarley, on Flickr


IMG_2996 by TheHarley, on Flickr

All the wiring is run under the fuel rails.  Once it is loomed it will be hidden real well and keep the top of the motor cleaned up.


IMG_2997 by TheHarley, on Flickr


IMG_2998 by TheHarley, on Flickr


IMG_2999 by TheHarley, on Flickr

The toe tags with connector end views are handy too.  Makes identifying circuits, sensors, and connectors quick.


IMG_3000 by TheHarley, on Flickr

Unloading the cab with the forks on the tractor

IMG00042-20110314-2116.jpg by TheHarley, on Flickr

IMG00045-20110314-2153.jpg by TheHarley, on Flickr

wiring looking good! jealous of the mock up you are able to do.
but as usual. progress looks SLOW

wiring looking good! jealous of the mock up you are able to do.
but as usual. progress looks SLOW

Looks?  It IS slow haha and I'll be the first to admit it.  Maybe the warm weather will fix that?  Planning on being back out there Friday night.

Congrats on making progress at all!

Cleaned up the barn and moved the cab over to the lift last week.


P3210175-2592 by TheHarley, on Flickr

Up and over...


P3210176-2592 by TheHarley, on Flickr

But it didn't go down all the way


P3210179-2592 by TheHarley, on Flickr

There was a bracket in the trans tunnel that it caught on initially.  Cut that out and the shifter location is into the floor now.  Between that and the height difference between the rear cab body mounts and the Blazer frame mounts I started thinking about the differences in frames and cabs of the trucks and SUVs.  Conveniently the standard cab rear mount lines up exactly with the second set of 2 door mounts.  Did some angle and height measurements and roughly came up with 2.75” difference.  Came into work yesterday and started grabbing part numbers and pulling them together in math.  The exact difference between the two is 77.5mm or ~3”.  Not too shabby with an analog angle finder, a measuring tape, and a couple old rusty trucks.

While I had the math up the difference between the trucks and SUVs that results in the height difference became very obvious too.  Turns out GM simply lowered the front suspension/steering about 36mm (~1.5”) in the frame.  The frame is also 1.5” taller throughout.  They left the location of the frame side body and engine mounts the same compared to absolute, but also added 5mm metal spacer on top of the body mounts for the SUVs to get an overall body height increase of about 1.6”.  There is only an extra 5mm of clearance between the frame and body on the SUVs though.  Would be easy for a 2nd gen Blazer to gain that extra few inches by swapping front clips and body mounts, but I’m happy with what I have for several reasons.  First I have the Blazer frame already, second the extra cross section is stronger, and third I can drop the motor/trans down with a modified upper engine mount to help with clearances and CG.  The Blazer has that extra 1.5” between the oil pan and engine cross member.  I’ll probably shorten up the body mounts the 5mm too after dropping the drive train.

I still need to set the drive train angle before making any solid decisions (thinking the stock 5-6*).  Part of that is getting the rear centered in my preferred ride height range; another decision.

So far using this for mockup is paying off.  Going to need to rethink where and how I pull the wires through the firewall to keep the stock heater box.  We wouldn't have thought to lower the motor until dropping the Blazer body on.  This is much lighter...  Still looks like good clearance to the firewall and once all the other issues are ironed out may be able to push the motor back further.  I will be piecing together the rest of the equation with the firewall as I see good or free deals and working on the wiring and drive train height in the mean time; already picked up a brake booster.


P3210180-2592 by TheHarley, on Flickr


P3210177-2592 by TheHarley, on Flickr

Forgot to show how we lightened up the cab....

Click for a Video

So this will be a blazer again, right?

Or are you going to make it a super short bed standard cab?

the video is set to private, can't watch it.

the video is set to private, can't watch it.

Should be fixed now.

It will stay a Blazer, but using this for mockup is much easier to work around than a complete Blazer body. especially one I don't want to bang up.  The rockers on this cab get shorter everytime we move it around hahaha.

hmm... since im always thinking about how I can benefit from your hard work....
does this mean that you can mock up a trans crossmember that will work for you, which will be a bolt-on for me?


and shit. 1.5" of extra frame section is just not fair.
i want a blazer frame....
although i have been thinking.... cut all the crossmembers out, and widen the rails apart... = instant extra clearance for everything + wider track + well, pretty much everything is a plus, except the extra work.

haha that might be a first, buying an entire cab to use just for mock up. It's cool to see your taking your time and really thinking things through. I wish I had that kind of patience and while I'm at it I wish I had your garage too!

oh that poor cab.... looked like it had good metal on it too

hmm... since im always thinking about how I can benefit from your hard work....
does this mean that you can mock up a trans crossmember that will work for you, which will be a bolt-on for me?


and shit. 1.5" of extra frame section is just not fair.
i want a blazer frame....
although i have been thinking.... cut all the crossmembers out, and widen the rails apart... = instant extra clearance for everything + wider track + well, pretty much everything is a plus, except the extra work.

From what I know about the frames the transmission mounting is different between the trucks and SUVs too.  Text me a reminder tomorrow and I'll try and hunt down a long bed frame and pull it into math to compare.  I'd love to save us that time up front on a swap for you.  Especially since all the welding could be done without a cab and bed in the way.

The 1.5" is nice for the motor, but it still means the body is that much higher too affecting CG.  Dropping it in the suspension that extra affects the geometry.  Basically a truck is 1.5" lower for the same suspension geometry on a Blazer.  That seemed to be common knowledge before, but just didn't know what in the frame caused it.  I always thought body mount location, but was way wrong.  Now I just need to convince Al to use his document surfing skills to dig up the why they did it that way.

The cab was pretty much scrap at this point in its life.  The rockers are slowly falling apart as I move the cab around.  We cut off most of the good metal anyway haha.  It was a perfect candidate for this and we got enough other parts with it that it will pay for itself and hopefully help jump start a used S10 parts business I've been kicking around in my head with my friend, Al, whose barn I take up space in.  I won't say taking my time with it is easy.  There are definitely days when I see others getting their swaps done and hitting the road that I'm jealous, but I'm learning a lot that I think can help make everyone's future swaps better.  Besides it will be done in much the way I've been dreaming for years now.

never understood why GM would make the s10 and blazer frames different.  My only guess is that they wanted a frame with less flex since the blazer's body sits on the whole frame and the s10 body only mounts to half the frame.  plus the extra weight of the blazer body.

that being said, I still don't understand why they had to raise the blazers up.

never understood why GM would make the s10 and blazer frames different.  My only guess is that they wanted a frame with less flex since the blazer's body sits on the whole frame and the s10 body only mounts to half the frame.  plus the extra weight of the blazer body.

that being said, I still don't understand why they had to raise the blazers up.

That was actually the best conclusion we had from our lunch conversation on the topic.  They needed the extra frame height for rigidity and couldn't get it without moving the SUV body "higher" everything else considered.  Just making the frame taller reduces ground clearance.  If you look at the two frames in math it does seem to make a lot more sense how they did it too.

a clear measurement on how far to move the mount hole is really all i need, but wont hurt to do some more learnings 

remember, most people dont like lowered trucks/SUVs.

so having it 'look' higher stanced from factory may have given it a more 'premium' feel to it.

effect you see with all the CUVs running around nowadays

but for GM, making a whole new frame for a shared frame design in its second iteration is kinda expensive...

but maybe thats why the 2nd gen suvs took an extra year to come out. 94 vs 95

The last several shop nights I've been chipping away at the lowered engine mounts.  I decided to lower the engine about an inch to keep the pan above the crossmember.  Al and I have also discussed ideas for a skid plate below the pan to prevent road debris from hitting the pan directly.  Being cast it will break or crack instead of deform.

Lowering it definitely helps clearance from the transmission to the cab floor as well as the valve covers to the booster and heater box.  I'm hoping this will give me enough space to not drastically relocate the coils.

These are some prototype mounts to test the idea.  I've been playing around in CAD improving on the design and accuracy of the mounts available today to the actual parts GM designed (the engine and frame).  Plan is to get the designed mounts CNC'd somehow and off load the originals and prototypes to pad my $1000 swap budget.


IMG00081-20110509-2154.jpg by TheHarley, on Flickr


IMG00082-20110509-2154.jpg by TheHarley, on Flickr


P5090175 by TheHarley, on Flickr


P5090176 by TheHarley, on Flickr


P5160200 by TheHarley, on Flickr


P5160201 by TheHarley, on Flickr


P5160205 by TheHarley, on Flickr


P5160206 by TheHarley, on Flickr

The cross member is sitting on the wood to set my ride height, but it is also a good reference to check the location of the oil pan.


P5160207 by TheHarley, on Flickr

Perf.


P5160208 by TheHarley, on Flickr

Plenty of transmission clearance now.  Before it was into the floor.  Most of that contact could probably have been fixed by cutting the shifter hole, but I feel this is the better way to do it.


P5160210 by TheHarley, on Flickr

Next up is the transmission crossmember and checking manifold to steering shaft clearance.  With those out of the way the engine will be where it needs to be and I can start working out a lot of different things.  Here's my to do list right now.

Todo

• Prototype Engine Mounts
  
• Transmission Crossmember
• Steering Shaft Clearance
• Finalize Engine Mount Drawings
• Engine Harness
• Dash Harness
• Firewall Harness Grommet Location
• PCM/BEC Mounting
• Ignition Coil Clearance
• Exhaust Manifolds and Y Pipe
• Rear LCA Mount Chassis Brace
• Oil Pan Skid Plate
• Front Suspension
• Rear Suspension
• Burnouts!!!

Also once the harness is wrapped up I can theoretically start up the engine.  Snagged a fuel pump and sender from Parts Galore a couple weeks ago and have the original Blazer tank sitting in my garage waiting to be hooked up to this beast.

so jealous of your mock-up timeline.

when you get a chance can you compare 1st gen vs 2nd gen clutch pedal assemblies?
if they are close enough ill have a bigger selection at PG to grab an easier to access set.