V8 gurus - Lend me your collective engine location knowledge! (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

RWBeringer4x4

Mechanically Challenged
SILVER Star
Joined
Jul 11, 2012
Threads
139
Messages
5,435
Location
The People's Republik of Maryland
Hey all -

Finishing up fixing my V8 conversion (Gen 1 283 SBC) that my PO had butchered. I stick mostly to the @Downey conversion manual, but I've run into an (anticipated) issue clearing my power steering pump.

Common wisdom says to mount the engine 1-1.5" toward the driver's side to allow for optimal driveshaft alignment. However, I'm going to run into a problem with this side-to-side adjustment.

Below is with the engine "dead center" between the frame rails, with the crank center at 12.25" from both frame rails to the crank about. This allows for full outward pump adjustment -

image.jpeg


I'm trying to figure out how running the V8 centered will affect driveline angle. To the naked eye, this doesn't seem too bad:


image.jpeg


There's definitely a BIT of deflection
image.jpeg


Is there a good way to measure the "side-to-side" angle of the driveshaft?

I used an angle finder on the pinion flanges and the vertical alignment is good (within ~2 degrees of parallel) but I'm not sure how to measure the deflection from side to side.

Is anyone else running the engine centered? Will this result in bad driveline vibrations?

The issue is, even at 1" to the driver's side, I lose about 1/2 the adjustment on my power steering pump. Below is the max adjustment with the engine 1" to the driver's side:

image.jpeg


In short - where do I make the compromise? Not sure that's enough steering pump adjustment to be able to install and adjust a belt, but I'm not sure how to determine if I'll have driveline issues if I run the engine centered. Are there other clearance issues on the passenger side I need to consider?
 
Early cruisers ran a centered diff with offset transfercase from the factory!! Built a dozen v8 cruisers with a little offset and never had driveline issues, you will be fine clearing your pump. No worries mate!
 
After centering my rear diff and going to center rear output t/case, and with the engine offset to the left, my d/s is not even close to being in line. Its mostly a trail rig, but I have no vibration on the blacktop.
I think my pinion flange and t/case flange are around 2* from parallel.
 
Early cruisers ran a centered diff with offset transfercase from the factory!! Built a dozen v8 cruisers with a little offset and never had driveline issues, you will be fine clearing your pump. No worries mate!

Never realized the earliest cruisers ran a centered real axle...certainly promising!

After centering my rear diff and going to center rear output t/case, and with the engine offset to the left, my d/s is not even close to being in line. Its mostly a trail rig, but I have no vibration on the blacktop.
I think my pinion flange and t/case flange are around 2* from parallel.

@pb4ugo - is this the stock 6 cylinder, or did you just swap axles and transmissions? My rear transfer-case and pinion flanges are definitely within 2 degrees of parallel. The front is closer to 5 degrees, but that is less of a concern to me because it won't be used often, and when it does, it will be at fairly low speed.

This rear is probably pretty darn close to "in-line" but I'm curious as to why the V8 folks all recommend the 1" (or more) offset. I'm guessing this probably aligns the driveshaft "perfectly," but if I can get away with running it centered, it certainly solves the driver's side clearance issues.

How about passenger side clearance? What do I have to worry about in terms of components conflicting with the driveshaft? We've got the exhaust Y-pipe, starter, clutch fork, and fuel pump over there but I can't imagine them being problematic...

@bikersmurf - I know you're running a Gen 1 - pining you as you are typically a wealth of knowledge when it comes to this stuff!
 
I don't think you will have a problem somewhat centering the engine between frame rails, stock location was 1" towards drivers side on LH drive vehicles, but here's my other observations:
(1) It looks like you cut the stock steering drive shaft off a bit short, making the upper steering u-joint mount up closer to the firewall. This also makes the new steering drive shaft route closer to the engine- - further away from the frame.
(2) I could be wrong, but it looks like your power steering pump pulley is a larger O.D. than I recall them being???
 
I don't think you will have a problem somewhat centering the engine between frame rails, stock location was 1" towards drivers side on LH drive vehicles, but here's my other observations:
(1) It looks like you cut the stock steering drive shaft off a bit short, making the upper steering u-joint mount up closer to the firewall. This also makes the new steering drive shaft route closer to the engine- - further away from the frame.
(2) I could be wrong, but it looks like your power steering pump pulley is a larger O.D. than I recall them being???

Thanks for chiming in Jim! in response:

1. When I first bought this truck, I had to re-do a REALLY bad (dangerously bad) saginaw conversion performed by the previous owner. I didn't have a lot of meat left from the shaft the begin with. In addition, I had a shop handle it since I was new to this whole vehicle restoration thing and didn't have the guts to tackle it myself - so I was sort of at their mercy. There's a couple things I would have done differently, but at this point, it is what it is.

2. That pulley is the same OD as the one I destroyed removing it from my old pump :meh:. The pulley actually doesn't extend beyond the wall of the pump reservoir. The reservoir is the real issue.

Out of curiosity - how much clearance do I really need to leave between components? Obviously the engine mounts, frame, and steering all have their own degree of flex, but I'm honestly not sure how much clearance is too little clearance...
 
Rick, My original conversion was similar to yours, except with a mid 70's 350 SBC and stk trans & t/case. I offset it to the left during the conversion. After breaking several Toyota T/cases and dana 18 cases, I opted for a center rear output dana 20 case and centered the rear diff. I think offsetting a SBC is to align the driveshaft flanges like the stk 6 was. The difference I see in my original SBC conversion and yours is the power steering pump setup. I run a long chev water pump and my power steering bracket hangs off of it, which brings the P/S pump closer to the crank. It also rotates the pump up and out slightly when tightening the belt. This gave me more room for the sag steering shaft. I use a short belt which I have to sort of pry on to get it installed, so my pump adjustment is minimal.

My frt D/S angle is what it is. I get slight vibration if my hubs are locked driving on the blacktop. When I went to center rear output I had to lower my t/case rear output so the frt output angle is even worse than b4.
 
Rick, My original conversion was similar to yours, except with a mid 70's 350 SBC and stk trans & t/case. I offset it to the left during the conversion. After breaking several Toyota T/cases and dana 18 cases, I opted for a center rear output dana 20 case and centered the rear diff. I think offsetting a SBC is to align the driveshaft flanges like the stk 6 was. The difference I see in my original SBC conversion and yours is the power steering pump setup. I run a long chev water pump and my power steering bracket hangs off of it, which brings the P/S pump closer to the crank. It also rotates the pump up and out slightly when tightening the belt. This gave me more room for the sag steering shaft. I use a short belt which I have to sort of pry on to get it installed, so my pump adjustment is minimal.

My frt D/S angle is what it is. I get slight vibration if my hubs are locked driving on the blacktop. When I went to center rear output I had to lower my t/case rear output so the frt output angle is even worse than b4.

Yep - the long-pump setup is definitely more friendly, I was just trying to avoid buying all new pulleys and brackets as they really start to add up. Offsetting the V8 is definitely to keep the driveshafts aligned and parallel. The problem is there isn't really a good way to measure how far out of parallel they get with a centered engine. sounds like I may need to drop some plumb lines and draw on my garage floor!
 
Just use chalk, you'll be fine.
 
Guess this won't help you being as how you don't have bolt holes I your heads I
image.jpg

But might give an idea I think the v8 has to be offset
1in to the right to clear the stock steering box
When this had the ram horn exhausts in it and stock box there was maybe 3/8 to 1/2 in clearance
 
Guess this won't help you being as how you don't have bolt holes I your heads IView attachment 1443786
But might give an idea I think the v8 has to be offset
1in to the right to clear the stock steering box
When this had the ram horn exhausts in it and stock box there was maybe 3/8 to 1/2 in clearance

It's a definite possibility, but I believe the 2F was also offset 1" or so to the driver's side as well. My guess is, more than anything it has to do with driveshaft angles...

Definitely wish I had accessory holes in the head - it would solve a lot of problems!
 
@RWBeringer4x4 my 40 had a 327 no holes in heads originally
I held off doing the powersteering because of the same problem you are having mounting the pump
Two years ago I had enough of hearding it around on 38s and swapped in this motor
One option is to get a power steering pump
Out of a jeep Cherokee that has a remote res
And swap a v grove pulley on it
S10s and some of the gm fwd cars use a similar pump they are roughly the diameter of a pop or beer can and shorter than the ham can pump
I was going to use one but the motor swap was quicker and easier
 
Ok guys, so bear with me and let me know if I've got the lines drawn right to determine my driveshaft angle:

1. Drop plumb lines form both transfercase flanges and mark the ground - connect the dots on the floor to form a line (blue)
2. Drop plumb lines from both front and rear pinion - connect these dots. (Red)

These lines should be parallel if the engine is in the truck straight/square. This should give me the offset between pinion and transfercase flange

3. From there - I should be able to draw a diagonal line between the two plum lines, which should represent the driveshaft angle. (yellow)
4. draw lines at 90 degrees at each pinion flange, and I've built some 90 degree triangles on the garage floor which should allow we my calculate
the angle of the driveshaft (Green)

Here is my MS paint attempt to explain what I'm talking about.

drivelines-png.1444407


If the two plumb lines end up NOT parallel, this would have to be because the engine is not mounted square in the frame - I should be able to draw a parallel line that intersects with the one that isn't, and figure out how far off it is by the same method.

Am I thinking about this right?
 
When I did my swap many moons ago I tied a string from the front diff flange to the back diff flange. Had the motor loose and aligned t/c flanges as close to in line with the string as possible. Raised the motor with fan installed to get it as close the the center of the radiator as I could. Built everything else to fit after that.
If you are using a short water pump set up you can get a very simple p/s pump mount plate from Speedway Motors that bolts to the lower d/s engine block. Just find a belt that limits adjustment towards your steering rod.
 
Don't worry about it. Driveline angle is driveline angle whether on a perfectly horzontal, vertical or anything in between. All that matters is the specific angle at each joint. If you cycle the suspension through travel and see no binding you'll be fine. There are more than two dimensions in space. If you were to bolt them up and lift the left side of the truck eventually the plane of the driveshaft would line up nice and vertical
 
Your drawing is way over-thinking this.
(1) the stock factory drive shafts were already on an angle.
(2) front and rear shafts will never be on the same angle unless the transfer-case is dead centered between them.
(3) Toyota's lavish u-joint angles will eat up any deviation.
 
Don't worry about it. Driveline angle is driveline angle whether on a perfectly horzontal, vertical or anything in between. All that matters is the specific angle at each joint. If you cycle the suspension through travel and see no binding you'll be fine. There are more than two dimensions in space. If you were to bolt them up and lift the left side of the truck eventually the plane of the driveshaft would line up nice and vertical

Understood - just trying to make sure I won't have vibration under normal (road) driving conditions. My understanding is if things aren't perfectly parallel, or the angle is too steep (horizontal or vertical) I'll run into issues.

Just eyeballing it - the vertical angle seems well within reason on the rear driveshaft, just trying to figure out the deflection side-to-side

image.jpeg
 
Your drawing is way over-thinking this.
(1) the stock factory drive shafts were already on an angle.
(2) front and rear shafts will never be on the same angle unless the transfer-case is dead centered between them.
(3) Toyota's lavish u-joint angles will eat up any deviation.

Thanks Jim -

I'm sure I am overthinking it - but just trying to learn/understand how all this stuff works - it's why I bought the truck in the first place!

Toyota's lavish U-joint angles weren't lavish enough to prevent binding under droop with the PO's setup - just want to make sure I'm not making the same mistake!

Since you're here - your manual recommends the passenger side offset - is this just to maintain the original shaft alignment? In your experience with conversions - did you ever cheat any of the engines toward center as I'm suggesting? To be honest, what I'm looking at is truly 100% centering the engine. I think the farthest I could get toward the driver's side is about 1/4" - certainly not 1"
 
Last edited:
I don't know if Toyota off-set the engine 1" towards the drivers side for weight distribution, or if to reduce angle on the drive shafts, or to keep the transfer-case off of the RH frame rail???? Downey motor mounts always had long slotted hole for moving the engine from side to side, allowing discretion in engine positioning, but our rear transfer-case crossmember did have a 1" shift to the driver's side built-in.
 
Understood - just trying to make sure I won't have vibration under normal (road) driving conditions. My understanding is if things aren't perfectly parallel, or the angle is too steep (horizontal or vertical) I'll run into issues.

Just eyeballing it - the vertical angle seems well within reason on the rear driveshaft, just trying to figure out the deflection side-to-side

View attachment 1444465

Theories are a good start point. I've had driveshafts balance when they shouldn't and not when they should. I'm still waiting for the explanation of how an 80 front driveshaft only runs smooth 90 degrees out of phase
 

Users who are viewing this thread

Back
Top Bottom