71 Chevelle SS clone - 8.1L Swap

[Russell]

This is the ZF bracket:


This is the Saginaw bracket:



My understanding is that you can bolt a ZF pump up into either one with an adapter for the Saginaw bracket, but the Saginaw only fits in the second bracket.

These brackets came out of a motorhome that burnt to the ground.

The second set shipped this morning, it has a Saginaw pump in it already.

 

[ZooMad75]

I've never seen the adapter for the Saginaw bracket to the ZF pump. So that's a new one for me.

 

[Larry]

This is the ZF bracket:

My understanding is that you can bolt a ZF pump up into either one with an adapter for the Saginaw bracket, but the Saginaw only fits in the second bracket.

These brackets came out of a motorhome that burnt to the ground.

The second set shipped this morning, it has a Saginaw pump in it already.

Russlle,

That is correct, however the ZF pump that Workhorse used with an adapter to bolt onto the Saginaw bracket had a unique 2 bolt flange whereas the ZF pump that GM medium duty used on the ZF bracket had a 3 bolt flange. The ZF to Saginaw bracket was a Workhorse exclusive on W22’s and W24's. The GM Medium Duty version took a shorter belt and kept the pump tighter to the engine. I’m sure some other OEM used the 2 bolt flange ZF pump besides Workhorse but I know that 2 bolt flange pump still today costs a fortune through Workhorse parts……like over $500. Looks like you got the Workhorse brackets which is good because it will accept the Saginaw pump

ZF to Saginaw adapter. Workhorse part number W0000483. We have 6 of these in our PDC brand new if anybody ever wants one.

When I did my 8.1 swap back in 2008, I tried to use this set up in my K10 but the ZF adapter bracket pushes the pump too far down and too far out where it would contact the frame. I imagine it would even be worse in a car

Side by side comparison between the two different ZF setups. Workhorse on the left and GM medium duty on the right

You can see the GM Medium Duty on the right fits tighter to the engine and uses a shorter belt than the Workhorse version

Another unique thing about the GM Medium duty version is the pump bolts onto it instead of behind the bracket

I've never seen the adapter for the Saginaw bracket to the ZF pump. So that's a new one for me.

You just forgot dude. Why our South African engineers chose to have an exclusive bracket made is beyond me. This is also why the W22’s and higher had a unique serpentine belt….remember, the one we had all the chirp issues with?? I also tried to use this on the K10 during the 8.1 swap but it wouldn't fit. Next time you get a UPS truck in with a 4.8 or 6.0 look at the P/S pump. We used this same bracket to mount the ZF pump to the LS style bracketry as well.

 

[GWeakland620]

Sent you a message on Facebook @Russell

 

[kgblazerfive]

Get rid of the power steering pump find a manual steering box.

 

[Russell]

Got the 8.1L pulled out this week. On to cleaning the greaseball up and fitting it with the medium duty bracketry. The oil cooler hoses were leaking as per usual, and the seal on the timing cover for the harmonic balancer was leaking too so it is pretty caked up. Gotta love big skid steers capable of lifting a fully dressed cab and 1000+lb powertrain with ease haha!

 

[Larry]

Looks like fun! I’m sure you probably already know this so don't hate me if you do but, you don’t need to run an oil cooler on the engine unless you want too. You can just plug the fittings with regular ole pipe plugs then remove the oil bypass valve from the oil filter. There are two valves in there and the one you would want to remove is the one in the middle that is under the filter adapter. Just thread a bolt into it and yank it out. I ran out of real state to mount coolers on my rigs so I blocked off the oil cooler galleys but I would like to add a cooler someday as the 8.1 only holds 5 quarts w/o a cooler

This is the valve to remove

 

[diesel4me]

I deleted the oil cooler on my 6.2 ,I was told to loop the two ports in the block with tubing to avoid having the by-pass valve opening and restricting the amount of flow to the filter & engine..

However , I know of several 1 ton dump trucks with 6.2's in a fleet at a cranberry bog that had all their oil coolers deleted after they lost one engine to oil cooler hose failure,and the mechanic just plugged the ports with 3/8" pipe plugs..they are still hauling tons of berries every year..he claims the oil coolers weren't really large enough to make much difference..

I used 3/8" copper tubing & 3/8 NPT to 3/8" compression fittings to join the ports on my engine..no problems so far,been this way at least a few years..

 

[Russell]

I have no plan on putting an oil cooler into the Chevelle. I'll definitely be pulling the bypass valve out and blocking the ports with pipe plugs like Larry suggested. This car won't be pulling anything more than it's own fat butt around, so this engine will hardly work at all anyways.

 

[Kay86K5]

Good call, I removed the oil cooler and plugged the ports/removed the bypass valve too. Not a problem with mine at all, and all mine does is tow. Oil cooler lines annoy me, they leak all the freaking time

 

[diesel4me]

I am willing to bet more engines were ruined by the oil cooler hoses GM used on many trucks than the lack of an oil cooler--cheap aluminum tubing with poor crimped collars,the hose itself wasn't bad quality,but the tubing corrodes or the crimp collars blow off it..
I see no reason why a street driven vehicle needed one--maybe if they were towing full time or in desert heat conditions,but we never had any on older vehicles and didn't have much oil related engine failures..

I feel the same way about P/S coolers on cars--why do they need one when most don't weight half what older cars did ?...
I have by-passed a lot of rotted leaky P/S coolers with copper tubing & the proper rating rubber hose on a lot of vehicles and never had any troubles...if they felt one was a must,they could at least have used copper tubing instead of steel,which rusts at the spot welded brackets often ,then destroys the P/S pump after it runs dry..copper also transfers heat better..

 

[yellowK20]

I am willing to bet more engines were ruined by the oil cooler hoses GM used on many trucks than the lack of an oil cooler--cheap aluminum tubing with poor crimped collars,the hose itself wasn't bad quality,but the tubing corrodes or the crimp collars blow off it..
I see no reason why a street driven vehicle needed one--maybe if they were towing full time or in desert heat conditions,but we never had any on older vehicles and didn't have much oil related engine failures..

I feel the same way about P/S coolers on cars--why do they need one when most don't weight half what older cars did ?...
I have by-passed a lot of rotted leaky P/S coolers with copper tubing & the proper rating rubber hose on a lot of vehicles and never had any troubles...if they felt one was a must,they could at least have used copper tubing instead of steel,which rusts at the spot welded brackets often ,then destroys the P/S pump after it runs dry..copper also transfers heat better..

They don’t put them on for fun , they are on there because they are needed for that Application.

Now for This 8.1 going in a Chevelle yes I could see deleteing it.

 

[Russell]

A bit of an update on this build. Still not finished. Had a 2nd kid in Nov 2021 and haven't really touched the Chevelle since then. We recently moved and I need to build a new shop, so the car is sitting on the lift in my 3rd bay of the triple attached with all the rest of my shop stuff crammed in underneath it. I've just signed on the dotted line for the new shop, so hopefully I'll get the car into a position where I can start working on it again before spring.

That said, the 8.1L is in the car. I wound up tearing it right down to the long block and re-painting it. I put the custom made oil pan onto it and bought a Dart carburetor intake which I sent over to our good friend Heath at Volcano manifolds for an MPFI swap. He drilled out the injector bosses and fabricated a beautiful set of fuel rails for it. He also supplied a Holley Terminator MPFI system for LS engines which will drive the injectors and stock coil packs using the cam and crank sensors already in the 8.1L (which I updated to the newest version for reliability's sake). I had him also machine up a blocking plate for the distributor hole which will also serve as the PCV port. I chose to put it on the intake as there are issues with oil being splashed up against the valve covers which would have caused oil consumption issues. I put a couple breathers on the valve covers to supply fresh air into the engine. I put a Holley in-tank fuel pump into the car and ran the fuel up using the stock hard lines plus some earl vapor guard hose. I had some clearance issues between the Saginaw power steering pump and the 97 Jeep ZJ steering box I put onto the car for a more modern assist feel with a full range of steering angle (bolts right up!) so I swapped to a GM Type 2 power steering pump which cleared up all the clearance issues. I put a set of Flowmaster headers on it as well. Mechanically, the only thing the engine still needs done is to get the mounting bosses for the AC compressor welded up to the compressor head (still not sure if that's gonna work out or not...) and to add the bracketry for the cruise control module. I installed a hydraulic throw out bearing into the muncie and converted it to a hydraulic clutch pedal. I added a hydrobooster and did a rear disc brake swap, I've got the classic air AC system mostly installed and a set of BMW E93 sport coupe seats installed up front as well. Still need to do all of the wiring throughout and get the exhaust done up. It'll be a while before I have a space to work on the car again, but I'll get it done eventually!

 

[centexk5]

Good to know the 8.1 fits in a chevelle. Can’t wait to see this one done.

 

[folkenheath]

Good to see Russell, I have been wondering how the project was going, congrats on the family expansion.

I hope to see a video of it running.

 

[ZooMad75]

Right on! Congrats on the kiddo too!

The 8.1 looks great in there with the carb style intake. Way better looking in there than the truck intake for sure.

 

[Chevy305]

Nice update!

 

[ZooMad75]

Looking back at the pics on a bigger screen I noticed the a/c compressor. It looks like a Sanden with the HT6 front mounts. Where did it come from?

 

[Russell]

The Sanden compressor is an SD7H15 part number 4261 for an 01/02 LB7 Duramax truck. I replaced the head with a type KG head because of hood clearance issues with having the exit off the top in the stock configuration. The problem I ran into is that the 4261 has the rear two mounting feet integrated into the stock head, while the KG head does not have any mounting feet. I cut the mounting feet off the stock head and intend to weld them onto the KG head to regain the rear two mounting points but it may well destroy the head with warpage by doing so. We shall see how it works out. If it doesn't, I'm not sure how I'm going to deal with the AC compressor without running into the hood. There is no room to put it down low on either side.

 

[ZooMad75]

The Sanden compressor is an SD7H15 part number 4261 for an 01/02 LB7 Duramax truck. I replaced the head with a type KG head because of hood clearance issues with having the exit off the top in the stock configuration. The problem I ran into is that the 4261 has the rear two mounting feet integrated into the stock head, while the KG head does not have any mounting feet. I cut the mounting feet off the stock head and intend to weld them onto the KG head to regain the rear two mounting points but it may well destroy the head with warpage by doing so. We shall see how it works out. If it doesn't, I'm not sure how I'm going to deal with the AC compressor without running into the hood. There is no room to put it down low on either side.

That's perfect. I've been looking for a Sanden for when I do the a/c in my truck and really don't like the split housing the stock HT6 compressor has.

I see where you could have a problem with the top mount lines with the Chevelle hood. That looks like a stock Workhorse/G-van a/c bracket. Have you seen the plate steel version a guy makes/sells on one of the 8.1 facebook groups? Since his setup is not cast like the stock part I wonder if you could cut out a little of the bracket to drop it down enough and reweld it back together.