5.3 vortec engine placement question.

[gurskey]

Hi guys, I am in the middle of a 5.3 vortec, nv4500 swap in my 84 fj60. I have the engine in place and am preparing to have the motor mounts and crossmember welded in. I have evetything lined up well, and have no clearance issues. The engine sits 1 inch off center to the drivers side as the 2f did.....but I cannot for the life of me get the engine to sit squarely.......... in other words the passenger side cylinder head is 1 inch form the firewall, but the drivers side is 1 3/4 from the firewall.........so the whole drivetrain is "crooked".

All that being said. I have good driveshaft angles and the rear driveshaft is lined up so their is not a left or right angle to the rear driveshaft.......should i even worry that the drivetrain is slightly crooked?

 

[scrapdaddy]

If as you say, the driveshafts are straight with the engine, then I wouldn't worry as much about the firewall fitment.

What do the driveshaft angles look like when you square up the motor with the firewall.

Maybe the vehicle was hit hard in it's life.

 

[gurskey]

Vehicle was never wrecked. If motor is square to the firewall then the transfercase flange and rear end flange would not not exactly be facing each other. If the driveshaft is angled about a 1/2 inch left to right or vise versa, would this create vibrations?

 

[dbleon]

This is an interesting post. Wondering if its the firewall thats not square in relation to frame??

What reference point was used fo the engine mounts? Front of frame?

After working on mine, I get the idea that the geometry of everything is not always perfect and definately might be some minor variation between vehicles.

POST PICS

 

[gurskey]

I will look at it more tomorrow and post pictures. I actually have not measured from the front of the frame to motormounts( everywhere else about 100 times thuough). It is interesting because I have the driveshafts lined up. It is driving me nuts though. I would hate to get this together and have things vibrate.

 

[Elbert]

I don't think i would base alignment off the firewall... my 5.7 almost sits square with the radiator..... but I'm using stock mouts / Mark's adapter at the rear and advance adapter front mounts as I recall.

you can only come over to the drivers side so far before you get into the steering linkage.

 

[Texican]

Hey dummie the heads on all v type motors are offset......the one further forward front is #1 cyl this is because the cylinders across from one another share a crankshaft journal........

 

[gurskey]

Pretty sure that is not the case, Texican, but I will look.

 

[Elbert]

We set my engine as high as we could and still clear the hood, and then with the mounts loose move it over as far to the drivers side to get it square as possible. I know mine is a 5.7 ....and I had the benefit of using the stock rear mount as a placeholder.

 

[dbleon]

Hey dummie the heads on all v type motors are offset......the one further forward front is #1 cyl this is because the cylinders across from one another share a crankshaft journal........

That being said, the block is square correct?

 

[Elbert]

I knew I was on to something....

We set my engine as high as we could and still clear the hood, and then with the mounts loose move it over as far to the drivers side to get it square as possible. I know mine is a 5.7 ....and I had the benefit of using the stock rear mount as a placeholder.


Yeah...I did not even look at the firewall...but on my truck given the mounts I was using...I was locked into a certain position and the distance to the firewall was fixed for the most part. If I screw with mine again I'm going to move the engine farther back a little to gain a little bit of extra room between the water pump and the radiator core. I have a good bit of room between rear cylinder heads and firewall.

 

[Elbert]

once again...I don't see a need to measure or make calls on if the engine is square with teh firewall...you are more concerned about being square with the radiator...and generally not too close to the firewall ? Or thats the way I see it. OF course you don't want to be kissing the radiator core.

 

[Gumby]

I'll have to check but I believe bank offset is .8000 on the LS motor. That would account for your 3/4" difference.

What is the frame rail difference from the front of the block to the rear?

 

[gurskey]

Elbert, is your rear driveshaft perfectly inline (transfercase and rear end flanges pointing exactly at one and another with no offset to one side of the other?) . To me, the main concern is for the driveshaft to be square as it was when the 2f was still in, to eliminate even the slightest bit of compound angle when the driveshaft moves, that is what will keep everything smooth. I am going to do some more shifting tomorrow, I am so close right now I bet I am just not quite parallel on the flanges and need to shift things a little. I guess this were taking your time and measuring a hundred times pays off.

 

[gurskey]

I never noticed they are offset, but that would explain things if they are.

 

[gurskey]

Gumby, good call on checking the frame rail distances. I really have just been measuring the rear driveshaft alignment in relation to the frame rails as this is my major concern but obviously need to be looking at the front too. This is one of those instances where a tiny movement in the front or back of the drivetrain is multiplied at the other end due to the length and is a bit tedious to get it right.

 

[Mace]

Hey dummie the heads on all v type motors are offset......the one further forward front is #1 cyl this is because the cylinders across from one another share a crankshaft journal........

Pretty sure that is not the case, Texican, but I will look.

Good on you for looking..


That Texas dude knows a couple things..

 

[Elbert]

Elbert, is your rear driveshaft perfectly inline (transfercase and rear end flanges pointing exactly at one and another with no offset to one side of the other?) . To me, the main concern is for the driveshaft to be square as it was when the 2f was still in, to eliminate even the slightest bit of compound angle when the driveshaft moves, that is what will keep everything smooth. I am going to do some more shifting tomorrow, I am so close right now I bet I am just not quite parallel on the flanges and need to shift things a little. I guess this were taking your time and measuring a hundred times pays off.

I'm not sure as I write this reply... Since I have a marks adapter I'm using the stock rear mount so I'm locked into a certain baseline to start with. I agree with getting your driveline square/straight... thats what we did the best we could and then I moved the engine over to the drivers side some to try and get better square with teh radiator just for the purpose of trying to get the radiaotor fan to sit square with the radiator.

As to the question if they are perfectly inline...I'm not sure..I know we measured and looked at everything multiple times.....I did not have as many variable as you since I was in a sense locked into a certain position respective to the transmission and transfer case as the rear mount sits exactly as it did stock (transmission mount on stock positioned crossmember)...thats one of the reasons people use a marks adapter...the other of course is the mating from GM engine to yota transmission.

Nothing wrong with checking things out..

I've not had any issues with unusual vibration or eating universal joints or mounts.. or seals..

 

[MANUCHAO]

How are you making sure that the flanges on the pumpkins are aligned with the flanges on the TC ?
I used a string/wire from the rear axle flange to the front axle flange and lined up my TC this way.. yeah low tech but it works...
If you are using a mechanical fan I also would try to see that the engine fan is square to the radiator as supposed to it sitting in an angle.
If you are using an electric fan then this does not matter much.

 

[scrapdaddy]

Gurskey,

To answer your one concern, I wouldn't worry about the driveshaft being offset alittle. The u-joints will handle that, but if mine, I'd rather have the flanges in line than the firewall and motor.