ejs262's Suburban(s?)!
- Thread starter ejs262
- Start date
an engine is balanced before assembly, and I would imagine, GM balanced the engines by designating weights for the rods and pistons within a certain tolerance, and balanced the crank for that tolerance. My concern stems from the fact, that GM used the same crank with the 305 and 350. the 305 has a smaller bore, and therefore, smaller pistons, if a 350 crank were to be replaced with a 305 crank, the imbalance due to piston weight could be quite significant. I'm going try again and attempt to polish out the defects, and mic out the crank afterwards to make sure it's still in spec.
Race and performance engines are balanced and blueprinted before assembly. 1980s mass produced assembly line gm v8s were slapped together with the next parts coming down the line. It wasnt uncommon to have rods from different suppliers in an engine, those are called friday builds.
I wouldnt worry to much with the scoring as long as you get any high spots polished out you should be fine. I "rebuilt" a 70s 350 when I was in high school that was pretty similar too what yours is. I filed down the high spots and used emery paper to "polish" it. I ran that thing for 30k miles and the kid I sold it to ran it another 50k before the damn thing rusted away. If it were me and the heads were good Id throw a new short block in and be done with it. Im getting too old and cranky to piss around
I wouldnt worry to much with the scoring as long as you get any high spots polished out you should be fine. I "rebuilt" a 70s 350 when I was in high school that was pretty similar too what yours is. I filed down the high spots and used emery paper to "polish" it. I ran that thing for 30k miles and the kid I sold it to ran it another 50k before the damn thing rusted away. If it were me and the heads were good Id throw a new short block in and be done with it. Im getting too old and cranky to piss around
chilliwak
Expedition Leader
The Me262 is probaly the most advanced fighter of WW2. It was used as a basis for the Sabre and Mig fighters after the war used in the Korean theatre. The P38 is an outstanding aircraft too. You have god taste in aircraft and vehicles sir. Cheers, Chilli...?
usanumber1
Member
I'd skip 3/4 ton axles and just get the Dana 60 and 14BFF.
I'm going to use them for now, it works out really well for me for a few reasons, main one being that I have to find a Dana 60 before I can run one... lol.
engine is mostly back together, I painted some parts to make it look a little nicer going back in.
the oil pressure switch broke off in the block, and surprisingly, an "easy out" actually worked and got it out!? I still have a ton of work to do, but I've made a bunch of progress.
engine is mostly back together, I painted some parts to make it look a little nicer going back in.
the oil pressure switch broke off in the block, and surprisingly, an "easy out" actually worked and got it out!? I still have a ton of work to do, but I've made a bunch of progress.
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Ej I was looking at your sig and noticed you plan on an allison swap. I dont know if its been mentioned yet and it may not apply to the square bodies. The reason the gmt800s dont have the allison behind the 8.1 (i know youre going diesel) like the pickups, is because of the tunnel. Its too small for the allison too fit without either a body lift or some reconstruction. Something to look at while you have everything out and before you source your parts. The squarebody tunnel may be larger or you may have or plan on a bodylift. Just thought Id mention it.
zoomad75
K5 Camper guy
Small correction for you, GMT800 HD 2500/3500's with 8.1's did use the same Allison trans as the Dirtymax's. What didn't get an Allison was the 3/4 ton SUV's with the 8.1L engine. So a Suburban, Yukon XL or Avalanche 2500 came with the 4L80e. Also, the G-vans that used the 8.1's also used the 4L80e, including the RV cutaway units.
But I do agree, an Allison in a Square will need a bodylift and some creative tunnel work to make fit correctly.
I'm not afraid of a little cutting and welding to get the job done.
things are slowly coming together, it's going to look nice when I put it back in, and at this point, the only thing holding it back is the flywheel bolts, one of them didn't want to play nice coming out, so it has to be replaced... the air tube cleaned up nice, I'm surprised to see GM used stainless for it...
I picked up a set of "flat-top" knuckles from a D44 axle. they fit the 10 bolt and allow me to bolt a steering arm to the passenger side knuckle for the drag link to attach, so I can run crossover steering and improve steering under articulation.
things are slowly coming together, it's going to look nice when I put it back in, and at this point, the only thing holding it back is the flywheel bolts, one of them didn't want to play nice coming out, so it has to be replaced... the air tube cleaned up nice, I'm surprised to see GM used stainless for it...
I picked up a set of "flat-top" knuckles from a D44 axle. they fit the 10 bolt and allow me to bolt a steering arm to the passenger side knuckle for the drag link to attach, so I can run crossover steering and improve steering under articulation.
not really much to report. I'm hoping to have the engine back in by the end of the weekend. I removed the brackets for the quadshocks, and threw a little paint on the firewall, it looks way better in person, the rough top edge is GM's black seam sealer...
I also did an inspection of the wiring harness, and found a few things that I didn't like...
The PO seemed to think of this as a "Fix"
I cut the damage out, crimped a splice, and heat shrunk the affected wires.
then I found some abrasion damage on the TPS 5v ref.
again, I cut out the damage, and spliced in new wire.
I also found out the motor mounts I bought shortly after buying this truck, are not the right mounts, at all, and of coarse I don't have the boxes or receipts either... DOH. I also have heard plenty of stories of parts store mounts lasting a few weeks before failing, so maybe it's for the better, because I just ordered a set of poly engine and trans mounts.
The EGR solenoid that was on the truck had failed, and been plugged by the previous owner, so I also ordered a new on as well, hopefully it will clear the CEL that was in.
I also did an inspection of the wiring harness, and found a few things that I didn't like...
The PO seemed to think of this as a "Fix"
I cut the damage out, crimped a splice, and heat shrunk the affected wires.
then I found some abrasion damage on the TPS 5v ref.
again, I cut out the damage, and spliced in new wire.
I also found out the motor mounts I bought shortly after buying this truck, are not the right mounts, at all, and of coarse I don't have the boxes or receipts either... DOH. I also have heard plenty of stories of parts store mounts lasting a few weeks before failing, so maybe it's for the better, because I just ordered a set of poly engine and trans mounts.
The EGR solenoid that was on the truck had failed, and been plugged by the previous owner, so I also ordered a new on as well, hopefully it will clear the CEL that was in.
Here's a better shot of the wiring I had to repair:
I replaced the engine mount inserts. the old mounts fell apart bad. I wanted to use rubber to reduce NVH, but I couldn't find a rubber mount I liked, they all looked like cheap garbage.
The engine is ready to go back in the truck, with the exception of installing the flexplate, it won't fit between the stand and block.
I pulled the steering gearbox, shaft, and pump, in preparation for a frame reinforcement, a box brace, and an XJ steering shaft with U-joints. this part is actually what's holding me back from getting the engine back into the truck. of the four bolts holding the box on, only one was more than finger tight... ! on a more comforting note, I didn't see any cracks in the frame.
with the exception of the Y pipe, the exhaust is trash, I'll have to throw something together to get it roadworthy.
I replaced the engine mount inserts. the old mounts fell apart bad. I wanted to use rubber to reduce NVH, but I couldn't find a rubber mount I liked, they all looked like cheap garbage.
The engine is ready to go back in the truck, with the exception of installing the flexplate, it won't fit between the stand and block.
I pulled the steering gearbox, shaft, and pump, in preparation for a frame reinforcement, a box brace, and an XJ steering shaft with U-joints. this part is actually what's holding me back from getting the engine back into the truck. of the four bolts holding the box on, only one was more than finger tight... ! on a more comforting note, I didn't see any cracks in the frame.
with the exception of the Y pipe, the exhaust is trash, I'll have to throw something together to get it roadworthy.
tore down the 3/4 tone front axle to install new ball joints I also threw some paint on it:
the axle seals are inboard for some ungodly reason...
I got the new steering gearbox in, hopefully the box brace and frame support come in tomorrow
I noticed that between my 3 front axles, I have 2 different center links, one, from the 3/4 ton, is a 2 piece unit, the other 2 are three pieces. the 3/4 ton looks a little stronger.
I pulled the axles out of the spare 1/2 ton axle, I'm going to clean them up and keep them on the shelf just in case I break one of the 3/4 ton shafts.
the axle seals are inboard for some ungodly reason...
I got the new steering gearbox in, hopefully the box brace and frame support come in tomorrow
I noticed that between my 3 front axles, I have 2 different center links, one, from the 3/4 ton, is a 2 piece unit, the other 2 are three pieces. the 3/4 ton looks a little stronger.
I pulled the axles out of the spare 1/2 ton axle, I'm going to clean them up and keep them on the shelf just in case I break one of the 3/4 ton shafts.