47-54 ifs measurement

[whitedog76]

Does anyone have the measurement from the bottom of the frame to the top of the crossmember on a M2 setup? I'm looking into a M2 setup and trying go figure out if I'll have any clearance issues. (I have a front sump oil pan).

[dsraven]

there seems to be a few of them on here but not sure if they have a front sump pan or not. have you checked the build threads? what engine are you using?

if going MII, will you be using a put together system where the cross member is integral with the lower control arm pivot but not the upper? after doing one like that in a 57 chevy I would advise to invest in a cross member that has the upper and lower control arm pivots already welded onto the cross member. there is no guess work to be done as far as dimension between the two pivot points and also the angle of the upper control arm pivot for antidive geometry. that would all be engineered in when the cross member was built. you may want to check out the scotts hotrods front end for a view of what I am talking about. I bought a kit for my 57 and the cross member was not the right fit for the frame, angle wise fore to aft. after some trimming to fit, the upper control arm pivot ended up to be not in the right geometry anymore as well as the antidive angle was not correct. I figured it out as far as anti dive angle and the angle of the upper control arm compared to the lower (this affects the tire angle as the vehicle goes over a bump) but it was no picnic and definitely not a weekend job. research heidts site for a write up on proper MII geometry so you don't end up with bump steer or something else dangerous. some cheaper kits use a mish mash of stuff and the steering rack is not shortened to have the inner tie rod pivot correctly. this equals bump steer. better to spend a bit more and get a reputable kit. also I recommend to buy what you want for brake size, springs, ride height etc right away otherwise you spend more in the long run.
see the attached pic from the scott's site. notice the upper control arm pivots are integral to the cross member, the upper control arms are multi adjustable, there is motor mount plates already in place, inner tie rod pivot points are placed correctly to avoid bump steer (inline with upper and lower control arm pivot points), they use coil overs for adjustability of ride height, large sway bar set up and big brand name brakes brakes. if I was going to do it again I would look for a kit similar to this. then it is just a matter of getting the frame square and level, side to side, then getting the rake angle desired. blocking it up well so it can't move unexpectedly, then set the cross member in place and tack it all together. assemble front end and then assemble sheet metal to check wheel fitment in fender wheel openings (with correct tire size for the finished truck). if you like it all then take it apart and finish welding the cross member in place.
just my thoughts.

[dsraven]

the oil pan sump may be modified to fit the end product or a different pan and oil pump pick up may be installed. depending on the engine being used a stock oil pan from another model of vehicle may fit your needs. got a pic of what you have to work with?

[mr48chev]

I would have to think it might vary a bit between the different manufactures. Not a whole lot by any means but some are set to ride higher or lower than others.

I was trying to find the instructions for the "universal" crossmember I have as I believe it does have the measurements. I'll look on my old laptop when I get home.

[whitedog76]

I'm in the thinking stage of my project. I've thrown around a bunch of ideas in my head. Not really settled on anything. I have a Vortec 4200 mounted in my 54. Originally I was going to use the I beam frontend, but same issue. No room for oil pan. I've thought about a chassis swap. But, finding a Long Wheel base Trailblazer/Envoy that isn't wore out isn't easy. Not to mention all the fab work that would be needed to make it work.

As the truck sits right now, the oil pan is on top of the axle. Maybe 1/4" of give.

Most of the kits I've seen look similar in design. I would really like something with more of a stock ride height. I was just trying to see if anyone had some hard numbers.

Regardless of what I do, I know the oil pan will need to be modified. I'm just trying to figure out my best option.

This might give you an idea of what I'm working with. http://s1074.photobucket.com/user/wh...19939271050273 I've had to trim the front crossmember for the oil pan to clear right now.

Chris

[dsraven]

has anybody seen the classic trucks march 2017 edition? it has a write up on installing a motor and trans in a 47-53 chevy truck. the truck has a MII front end. it talks about CPP's products for motor mounts and trans cross member. the trans cross member bolts to the frame flange and the engine mounts are weld on and all adjustable prior to install by cutting to correct length.
anyway, it has some ideas. the engine trans is a small block chevy with a turbo 350 behind it. the concepts are the same for an LS engine if desired. just bear in mind the angles etc so you don't get a drive line vibration.
sorry, nothing about the atlas engine.
I am planning on using the atlas in my 57 but it will incorporate the envoy frame and running gear. hopefully the engine will fit, fore to aft, without too much trouble. shouldda used a 58-59-they are a bit longer out front. there is one done up on here somewhere though, rustymarco's thread. he sold the truck and moved out of country to the homeland.
for your dilemma, do you plan on welding up a new configuration for the pan or moving the engine up or back to miss the cross member or possibly some other option? have you cracked the pan open to see if there is room inside to allow for a pan modification?

[dsraven]

in regards to using an envoy or trailblazer under your truck, I think it would be too wide of a track width unless you want a huge offset wheel or want to run big truck fenders out front.

[dsraven]

just found this, finally, in my docs. does it help you at all?

[whitedog76]

Perfect, exactly what I was looking for. Actually, even better.

Thanks, Chris

[whitedog76]

Dsraven- I have seen the Classic Trucks issue, got it right here. It's kind of the reason I'm asking the questions that I am. Ironically enough, the trans crossmember they are using is almost identical to what I fabbed up.

I've spoken with member, Hampshire, about his 3600 truck. He's already done what I'm wanting to do. The crossmember on his IFS is about 2" lower and his spring hats are actually welded to the side of the frame. I'll still have some clearance issues with the rack and pinion even if I do that.

I can move the engine up about 3/4" and back about the same without having to do any sheet metal work to the body. After that, I'm building tunnels, etc..

Modifying the pan can get tricky with the 4200 because it's structural. In an OEM application the AC compressor bolts to it, the front diff is mounted to it and on the rear, the tranmsission is bolted to it. There is a gentleman in Canada that makes rear sump pans. He waits until he has a big order before he builds them though. Not to mention they're a little spendy. I can use a Chevy Colorado oil pick up tube and have my pan modified for a rearward sump, which is probably what I'll do. There are a couple Aluminum welding shops around here, so it shouldn't be a real big deal. Just more money.

I like the idea of a Trailblazer/Envoy chassis swap, but there are a lot of variables in that one too. You're right, the front is a little wide. With OE steel wheels and narrow tires it can be done though. The center part of the frame drops really low on the chassis and the rear has a huge frame kick up. So mounting the body and raising the bed floor so it doesn't look like a cobble mess is the biggest challenge.

Anyhow, thanks for the advice. I have lots to think about on this project.

[dsraven]

ya, I know what you mean about the frame on the envoy. I am planning on a swap in my 57 but it is wider than your AD truck and it will be touch and go even at that. especially if you want your truck lower like most. are you building a stock height or lowering it?
ever thought of fabbing up your own frame and using a MII front suspension? I have. not that much to it if you have fab skills and some extra cash for some scrap I beam or something to use as a frame table. the AD trucks are probably a little harder than the TF trucks because they have more bends in the frame (?) but do-able probably.
good luck, keep posting pics.

[dsraven]

have you looked at the welders series web site? they sell a do it yourself MII kit ( as well as a bunch of other handy stuff) and it could possibly be installed lower in the frame to accomodate the oil pan. your ride height would be affected and you would possibly want to add supports for reinforcing the cross member because the added distance away from the frame would mean the cross member has more leverage to bend something or break the welds attaching it to the frame. there are also other options like a complete front end that bolts in, like a chevy truck from the '60s era up into the 80's. again, too wide. what about a dodge dakota front end, I suppose it would interfere as well.
are you planning a stock height, lowered or a big truck look with the big truck front end? a 3600 is the same size as a 1/2 ton,correct? not a big truck front end?

[dsraven]

just found hampshire on here and took a look at his truck. nice. it looks like a stock height or close. if that is the outcome you are going for then it makes things a bit easier at least. I would try really hard not to have to modify the oil pan. it just makes things harder and more involved. I know there is a shortage of room in the cab (thinking about a modifed firewall) but wondering how far back the engine would need to go for it to clear the cross member. I have seen a crown vic front end installed into something on here before, just can't remember what. it is also a one piece bolt on but not sure of the track width.

below is a track width page from crankshaft coalition. maybe some help for you.just copy and paste to google. it gives wheel base, track width front and rear

http://www.crankshaftcoalition.com/w...l_measurements

[whitedog76]

I'm going for more of a stock height truck. Hampshire claims to be about a 2" drop. His kit doesn't have the notch in the frame for the rack/pinion either.

Since we've been talking, I've been doing alot of measuring. The top of my pan comes right to the bottom of my frame. The oil pan is 8" deep, so if you look at the 3 7/8" measurement you gave me, there is still room for improvement. A 2" lower crossmember improves on things though.

My I beam axle hits between 9 and 11" back on the oil pan, which is at the very back portion of the sump.

Here's a pic of the pan, it would be just behind the axle mount hole.

[whitedog76]

On another note. I got to looking at an IFS system. If the crossmember were moved back to where the lower control arm extensions are, it would be a much better setup for me. I could flip flop the spindles side to side and possibly use a rear mount rack and pinion. Which is how Trailblazers are set up. I may have to do a small notch in the pan, but nothing major.

[dsraven]

the 2" drop usually comes from the spindles but looking at hampshires it looks like he dropped the cross member the 2" since his spring "hats" are below the top of the frame.
you could, if you have room between the upper control arm pivots, (and you must since hampshire apparently does) move the cross member down as far as you like and then move the "hats" down the same amount. as long as the geometry stays the same. there is usually a 4 deg down slope on the upper control arms (fore to aft) for the antidive angle. also, the lower control arms, at ride height, should be parallel to the ground (level side to side) and the uppers will have a small downward slope towards the inside. this is so when the wheels go over a bump the tires actually tip inwards so they don't rub the fenders, especially when turning. it is all about how the ball joints react in an arc as the suspension moves and how the upper and lower control arms are different lengths etc.
another thing to factor in, if you flip the cross member so it is backwards, is the distance that the rack stands off the cross member. this will affect bump steer if it is wrong. it is supposed to be inline with the tie rod ends at the steering spindle ends. so if you draw a line from one outer tie rod across to the other the rack should be dead straight wand inline with that line.
also, the inner tie rod pivots need to intersect a line drawn from the upper and lower control arm pivots with the steering straight ahead. this helps eliminate bump steer. you can figure out why bump steer happens easily if you think about it. if the pivot points are not inline then the tie rods effectively get longer or shorter, in relation to the outer tie rod end connection, as the suspension moves.
anyway, you probably already knew that.
end of rant, haha
good luck, keep us posted. pics are great

[dsraven]

how about if you draw it all out on paper. first show frame position and then add the engine position (as high as possible without hitting the hood). then see what you have left for room below or how far down a cross member would need to be. a side view would show you if the flipped cross member would work. a rear steer may be difficult to connect the dots to the steering shaft without massive u joint angles?

[whitedog76]

Moving the drivetrain up won't really solve much. Just create more problems and more sheet metal work for me.

Here's another side profile. You can see the frontend is pretty high. Part of that is due to the 235 weighing probably 2/3's of what the 235 did. As it sits right now, using the measurements in your pic, would give me a 5" drop. The 54/55 trucks are basically a straight frame truck. Very little kickup at the rear. So, I would have to do a huge c- notch and raise the bed floor.

[whitedog76]

I'm still liking the flipping the crossmember around idea though. I would just need to figure out the new centerline and go from there.

On the pan, I could notch quite a bit out of the back and still not cause too much grief. As you can tell, part of it is notched already.

[dsraven]

maybe try taking the pan, or a pic of the pan, to a fab shop and ask how much to do the remake. make sure the pan is clean before you take it there or they will charge extra and the weld may be poor. aluminum welding needs to be super clean. then weigh it out against the cost of the Canadian dude along with the exchange rate (good for you) and shipping.

[dsraven]

what about modifying the cross member in the mid section to clear the pan? like a U shape?

ok, this may be out there.
how about you box the frame with some 3/16 flat plate from, say, under the cab somewhere. longer than most MII set ups usually do. then fab up some thick flat plates that can be welded to the inside of the frame and hang below and above the frame. they could provide provisions for the control arms to be mounted on, upper and lower. there would be no cross member under the engine. the cross member to control frame flex and mount the steering rack could be ahead of the engine. the frame is boxed, like an envoy is, to assist with frame flex and a beefy cross member is fabbed up and placed ahead of the engine like an envoy has.
I was just looking at canadian hotrods site and some others and noticed that they use a plate like that for their custom frames. they use corvette underpinnings but you could use whatever you decide. even S10/monte carlo control arms. the nice thing about MII is there are drawings with dimensions for pivot points andspacing of items etc so as long as the geometry is correct it should work. TCI and others use an upper control arm set up that mounts differently to the frame than the boxes that some kits use (like mine) they may work for you. maybe worthwhile to check their site out for ideas. keep in mind that the envoy cross member is pretty big, assuming to control frame flex?

ya, I know. out there right?

[dsraven]

http://www.canadianhotrodsinc.com/?l...aItem-it4x083n

try copy and paste to google for a pic.
what I was thinking is the flat plate would extend below the frame as well, in the correct location for the lower control arm pivots, and the cross member would be ahead of all that, like an envoy. just make it heavy enough to control frame flex, and it could also be gussetted towards the rear on each side of the engine if need be. you could link the two sides with a bolt in cross member under the engine, connected to the lower cotrol arm mounting area, to assist with flex. bent to what ever is needed to connect the dots there. the trans cross member could also be a bit beefier to assist with flex at the rear of the engine/trans.

ya, I live in Canada and it's cold here today. maybe brain freeze, haha.

[whitedog76]

We're getting your Canadian air here too. High of 11 F today! LOL

I like their chassis designs. A little too fancy for me.

Another thought is to install the said ifs, fab up rear crossmember, gusset everything together ( a K member of sorts), then chop the center out of the original crossmember.

Geesh! My ADHD is overtime today!

I think I need to get the welder and grinder out and just start working.

[dsraven]

here is some stuff on steering geometry for you.

Heidts, Understanding ifs pg 1.pdf

Heidts, Understanding ifs pg 2.pdf


http://www.heidts.com/wp-content/uploads/IN-216.pdf


http://www.hotrod.com/articles/indep...nt-suspension/
scroll down for definitions and stuff to think about when setting up


http://www.rqriley.com/suspensn.htm
another descriptive read with definitions and expanations. good to know stuff


envoy track/Tread width is given as 63.1" front and 62.1 " rear. The engineering specification for tread is centerline of rear tire to centerline of rear tire.

if you pm me I can send you the envoy frame dimensions for my 04 xuv 4x4. should be the same as a 2wd I would think. it is a long wheelbase like an xl but has some whizzy body features. or you could email the gm heritage centre and they will send them to you. mine is an acrobat file and I can't seem to send it on here or convert to pdf. sorry.

[dsraven]

-14 celcius here today. thats about 7 deg F.

I thought of the same thing with weld it in, gusset it, then cut it out as required. seems like a waste of a cross member though.

take a look at the welders series stuff. Canadian dollar is good for you right now. they have a tech page with dimensions as well. click on "IFS make your own " once you get their site up. it does have comments on the "T" bolt upper control arm adjusters compared to the "GM" style mounts with shims.
they have lots of other brackets and braces as well that could come in handy and look good in the process.

https://www.welderseries.com/