47-59 Help Please - 4x4 S10 swap questions

[JayB22]

Well I got back to working on the truck today. I cut out the rear cross member that was in the way of the transfer case. I mounted my motor and transmission into the frame. When I went to put the cab on I have no room between my cab and motor if I’m going to leave my cab mounts as they are. I slid the motor mounts as far forward as I could and it’s still tight. I also have a decent amount of lean towards the back with the motor. I’m hoping Joedoh or any of the other experienced builders can let me know how common this is or if I’ve used my s10 v8 swap motor mounts wrong. Maybe I need to flip them around to lower the motor a little bit? But as far as I can tell flipping the mourns around won’t lower the motor much if at all.

[JayB22]

I just did some playing around with a angle finder. The motor is installed at 6.8 degrees, the driveshaft angle will be 5.8 degrees and the rear ended is sitting at 6.2 degrees. From the pinion angle research I’ve done the driveline seems to be in spec. I’m just curious if there’s issues I’ll run into by running my motor at almost 7 deg insgall height. I realize you are constantly going up and down hills and around corners so nothing stays level for long. Just want to make sure I’m not making a big mistake.

[dsraven]

That's a lot of angle for the engine. Usually somewhere around the 3 deg is what guys use. If going carbed the intake mount surface for the carb will be level with the engine at 3 deg down at the rear.
S10 v8 swap mounts would place the engine correct for installing the v8 in an s10 bidy, not necessarily in an old truck. If you have access to an s10 you could figure out where the firewall would be for the s10 and compare to your truck body or go to the GM outfitters site bodybuilder manuals and choose the s/t series for some fun times looking for that drawing.

[Tempest67]

I can't help you with the angles, but I was very disappointed with the motor mount plates that were specifically made for V8 swaps in S10s.

The holes for the drivers side did not line up, so I had to cut the mount and add metal. I also did not like the way the plate was not supported underneath, so I made some brackets to support them.

Also, the SBC is a tight fit, so I cut the firewall and made a small indent to accommodate the pass. side valve cover.


You are making good progress, stay with it.

[JayB22]

Originally Posted by Tempest67

I can't help you with the angles, but I was very disappointed with the motor mount plates that were specifically made for V8 swaps in S10s.

The holes for the drivers side did not line up, so I had to cut the mount and add metal. I also did not like the way the plate was not supported underneath, so I made some brackets to support them.

Also, the SBC is a tight fit, so I cut the firewall and made a small indent to accommodate the pass. side valve cover.


You are making good progress, stay with it.

So with your install you also found that the passenger side stuck back a little more then the drivers side hey? I was getting worried I had something installed out of square or possible frame damage. Looks like I’ll have to pull the cab off and see what I can do with the motor mounts. I actually came across your build thread last night when researching this and saw you had done the modification to the firewall. Your build turned out great.

I had about 1.5” of clearance under the oil pan so I have room to go down but I definitely don’t want to use all of that space up. I’d like to get the motor closer to 3-4 deg of angle but I’m not sure if I should get too hung up on that. The motor angle, driveshaft angle and rear end angle all seem to be working well together, I’m starting to thing this could be a 4wd concern. I know worst case I can put a longer trans tunnel across the floor to allow the trans to come up a bit, the floor seems to bow down a bit in the middle anyway.

[burger]

Engines are typically mounted 3° down toward the back

[JayB22]

Originally Posted by burger

Engines are typically mounted 3° down toward the back

I understand that’s the recommended setup for a few different reasons. Just wondering how important that number is and if there’s risks at running the motor around 6 degrees. I figure I can maybe move the motor down about 3/4” which maybe buys me 1 degree of angle. If I need to get more then I’ll have to get into fabricating.

[dsraven]

Now this is just me, and I like to fab things, but I would place the engine with blocks to keep it where it needs to be. Consider firewall clearance, rad clearance exhaust manifold clearance, etcetc. Then bolt on some motor mounts to the engine, then connect the dots to the frame with posterboard to make templates that fit your situation. Then since posterboard can be a little flexible, transfer that pattern to something stiffer, like some cheap 1/4" plywood or hardboard. When you get the patterns like they need to be transfer them to steel, cut them out, test fit, tack weld etc and when they are right weld them up. You would be done by now and more satisfied. Use that 3 deg down angle with the frame at the rake angle you intend to use otherwise it all goes out the window when you put the truck down on the wheels for the final time. Since the engine is sitting on the frame now, put some approx weight on the rear to simulate the box, seats, bumper and other heavy stuff that may get added and that will help you realize the natural rake angle then you can pin the suspension at that height for reference and mock up of stuff like engine mounts, exhaust system etc

[dsraven]

the pass side of the engine will seem to be further back because the engine isn't a square cube, since the piston's connecting rods need room to fit on the crankshaft the drivers side, number one cylinder, is ahead of the passengers side, number two cylinder, because they can't be straight on with each other without having an offset connecting rod or something, if you understand what I'm saying. the even cylinders are therefore a little set back than the odd cylinders so the passenger's side valve cover is always the one to hit the firewall first. you can dimple the firewall, cut the firewall setback are

[dsraven]

sorry, hit enter by mistake there.
cut the firewall setback area out and make it wide enough for a v8 instead of the inline 6 it was made for, or move the engine ahead and then fight for room at the front of the set up when you get to that area next. I have a 16ga firewall set back that I fabbed up for a project and didn't use. pm me if interested or maybe just build your own. it is a common thing to need a firewall and floor "adjustment" when installing a v8, not to mention a frame swap.

[JayB22]

Thanks for all the ideas. I’ve decided to let the project sit til the weekend so I can deal with emergency calls at work and let the ideas stew in my head for how to correct all of this. You definitely like fabbing more then I do, but it’s cause I’m not used to it or as confident in it. Maybe it’s time to dive in and learn more about it. I originally was going to lean on some family and friends for help with stuff like this but so far I’ve done it all on my own and after getting this far I think I’m just going to continue doing it all on my own. Well with the help of all of you guys, which I greatly appreciate.

[dsraven]

thinking logically, the cab needs to fit where it needs to fit so the wheels will sit right in the fender openings. do this little job first and mark the location and height off the frame so you know where it has to be (even go so far as to cut blocks the correct height so the cab will be lowered over the engine, later, until the cab is sitting on those blocks. they can be kept in place with duct tape, screws or whatever or at least numbered or quickly spray painted different colors so you don't get mixed up later). then remove the cab and set it aside for now. the engine and trans also need to fit where they need to fit so that there is room for an engine fan etc up front and also so the oil pan will fit underneath and the other options, like a steering column, will also fit. some have offset the engine an inch towards the pass side to allow for a column with a minimal number of ujoints etc. there are a few different oil pans with different bumps here and there so hopefully you have the one that allows for the best fitment in regards to clearance out front and below. with this in mind, and with the frame at the desired rake angle and blocked there so it can't change, set the engine in place and at an acceptable angle, block it in there so it is stable and won't move around while you place the cab back on. I have found blocking and a couple of ratchet straps work well to keep things from moving but place the straps where they won't interfere with the cab placement. if you don't have cab mounts in place yet then use some blocks on the frame to set it level or at the rake angle you have decided to use for the frame, side to side and fore to aft. a magnetic digital level works well for this so if you decided to use, say, a 2 deg rake angle then the cab should also be at the 2 deg rake angle when mocking up. anyway, as you place the cab and lower it over the frame with the engine in place watch for the usual places where it is going to contact the engine. these places will need to be "worked" in order for the cab to fit down over the engine. this means a slight bump with a ball pein hammer or possibly a zip disc to cut away some material. you have already figured out the engine is where it needs to be so the cab is the part where the adjustments will need to be made. the way I figure it, usually, is the body needs to fit the donor frame first so you get the wheels in the fenders correctly, and then the driveline fits second to that. if you were installing a briggs and stratton lawn mower engine then there would be no problems but your engine is gonna take more room than that. you can't change the body location in relation to the wheels, and you can't change how the engine needs to fit into the frame. the change needs to come where the engine contacts the body. either the body raises off the frame, with the corresponding check for wheel fitment in the fenders, the engine drops in the frame, which is unlikely, or the body gets cut to fit the new engine size. not many options. I am sure if you check the AD trucks that run a stock frame you would likely see some firewall changes. don't mean to crush your eagerness to get it done, just saying some body changes may be in your future. even if the body was set higher off the frame you may need to adjust the firewall.

[joedoh]

Originally Posted by JayB22

I understand that’s the recommended setup for a few different reasons. Just wondering how important that number is and if there’s risks at running the motor around 6 degrees. I figure I can maybe move the motor down about 3/4” which maybe buys me 1 degree of angle. If I need to get more then I’ll have to get into fabricating.

the only thing i can think of is the gas overtopping the carb float on acceleration and the auto trans needing maybe a little more fluid to stay wet

[JayB22]

Dsraven - that was a similar insight I had on it last night so I had my neighbor come by and we put the fenders and grill on and put the body to where it needs to be. That’s where it was hitting the firewall. But as it is sitting right now with the motor touching the firewall I feel that I have the wheel gap set really well. So I think I will have to massage the firewall a by to fit the motor. The other issue I have is it looks like my hei distributor won’t fit as the vacuum advance part is hitting the firewall as well. So I may need to cut out a bit more of the firewall then I originally thought. I might look into other distributor options as well. In mocking up the motor and cab I cut some wood blocks that are the same thickness as the body mounts and used them to set the cab properly. I’ve been hesitant to drill holes for the mounts until I got the motor and trans in and everything sitting where it should be. I think my next plan will be to take the fenders off and see how much I can drop the motor down. I’m debating on just cutting the motor mounts down so they don’t lift the motor as high up. I just want to make sure I have room for that.

Here’s some photos of how the wheels fit in the fenders with the body on the spacers and the body moved forward as far as it can go until it hit the motor.

[JayB22]

Originally Posted by joedoh

the only thing i can think of is the gas overtopping the carb float on acceleration and the auto trans needing maybe a little more fluid to stay wet

I’ll be running a manual trans so that could help.

I was also debating on getting a intake spacer and maybe machining a couple degree angle to it to help if I run out of adjustment for the motor. I know this would effect the mounting bolts a little bit but I was hoping a degree or two wouldn’t be too bad if I split the difference on each side of it.

[dsraven]

looks like the wheels fit the fenders ok. on the engine, try to get the 3 deg angle if using a carb, it keeps the float bowls level so they don't overflow, when going uphill especially, and also helps the carb to run properly since the fuel will be the same level in the whole bowl. the trans and transfer case will also appreciate sitting at their proper angles. might as well do it right the first time so you aren't fiddling with the tune forever after or having trans problems on hills etc. the driveline angle will also be better since the original s10 likely had the 3 deg down angle. you may need to raise the cab or cut the floor a little since it is a 4x4 and the trans has a little more height at the transfer case mount likely. if you had the original s10 cab I would say just cut the floor and needed part of the firewall out of it and weld it or screw it down into your cab. you couild use the carpet from the s10 that way maybe. anyway, if the cab is sitting where it needs to be and the engine is sitting where it needs to be fore to aft, then the angle of the engine is the next hurdle along with a trans mount. it is easier to keep the driveline vibration to a minimum if the pinion and trans output angles are the same but opposite. one will cancell the other.

[JayB22]

This is what had me thinking maybe I was okay with my setup. The rear ended is set to just over 6 degrees. Which would be its factory setting. With the driveshaft working out to be around 5 degrees and the motor just over 6. All of the angles play well with each other. And if this was FI it wouldn’t be a issue at all.

I’m going to pull the front clip off and see how far down I can drop the motor and start there. I’m not worried to tunnel the cab if it’s needed. I was just trying to avoid it if possible. Half the reason is I can’t find a way to remove the seat bracket. Haha. I might dive back into that as well.

[dsraven]

I think the seat base is spot welded to the floor.

[JayB22]

Thanks. I was worried about that.

[Tempest67]

The other issue I have is it looks like my hei distributor won’t fit as the vacuum advance part is hitting the firewall as well.[/I]


Just install the distributor so the vacuum advance is facing the front of the engine.......... make sense?

[dsraven]

it seems like the fix might be to massage the firewall with a large ball pein hammer in the area where it is hitting the engine, then level up the engine some, which will give more room for the dizzy because the engine naturally moves away from the firewall at the top as the rear of the engine is lifted. you may need to watch the clearance under the floor for the trans/transfer case as you do this and also the engine front pully, not sue what you have for clearances in these spots.
if you need to fab a whole new firewall consider a steel wheelbarrow bucket, they are naturally rounded and may compliment the look under the hood and inside the cab that way. you could likely find a cheap one on kijiji. otherwise cut out what you need to in order to make it right the first time and then figure out how you will cover that hole after. remember to leave room for the gas pedal and your foot when doing this. it needs to be comfortable to drive when done.

[Tempest67]

Yes, the firewall may need a little 'work' because of the valve cover, but not the vacuum advance. - dont hack up the firewall because of the vacuum advance.

Just turn the distributor so the vac advance is facing forward. (see pic)

look where my vac advance is

[dsraven]

tempest is right, just spin the dizzy and movethe wires one tower over. it will be a pain to get the cap off but that doesn't/shouldn't happen too often anyway.
if you don't need too much of a dimple a hammer and dolly is one way to move the metal around. or just cut that piece out and shape a piece to fit the spot. try to avoid shap angles when you do that piece as they will draw the eye to that spot/ tempest's fix looks good.

[Tempest67]

I would like to say that I planned it this way, but I was focusing on making space for the valve cover, BUT .. it turned out to be a good place to run my 'engine' harness through, and the hydraulic line for the clutch.

[joedoh]

Originally Posted by JayB22

I was also debating on getting a intake spacer and maybe machining a couple degree angle to it to help if I run out of adjustment for the motor. I know this would effect the mounting bolts a little bit but I was hoping a degree or two wouldn’t be too bad if I split the difference on each side of it.

hey i may not know anything from nothing, but i suspect that if you are making parts to force it to work you might be too target focused.

the other guys have some good ideas, but oogway said we find our destiny on the road we take to avoid it, and if you spend a week thinking about how to keep from modifying the firewall and the floor, you might just go ahead and spend the couple hours modifying the firewall and floor.


on the seat riser, i dont cut the spot welds, i use a cutoff wheel and cut it off about a 1/4" from the floor, then tap it flat with a hammer. it keeps the floor stronger and doesnt get in the way