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Awesome paint skills right? I'm doing a build with a 3.4l GM V6 and (due to various reasons) am considering building my own engine mounts. I hope the diagram above makes some sense, here's my question, the tubing I'm using is 1.25" 16ga steel, I can't imagine that's enough for the upright (blue portion) is it? Any recommendations on how to change it/improve it or what tubing to use?

Obviously the drawing is not to scale or using the correct angles, just a rough sketch of what I have pictured in my head.

Thank you everyone

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Build Log (not much there yet): http://lotus.reddeth.com
442e frame, 3.4l Camaro donor

It depends on what mounts you are using and the bolt hole spacing on the block. Having the mount close to the chassis is better than an arrangement where the weight of the engine is acting on an arm to twist the lower chassis tubes.

More cross section is stiffer and more stable for a given wall thickness. 1.25" is not much cross section.

Take a picture from the front and side of one of the engine mount areas with the engine at the desired position, the desired mount laying on the frame rail and nothing bolted to the block.

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Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12

Yo Reddeth-
First, my standard disclaimer, "I ain't no engineer."

OK, now... Can you extend the lengths of the plates downward and towards the block so that they meet in an acute angle? Then, use the tubing to form the third side of the triangle. In addition, you could gusset the ends of the plates with triangles of the same plate steel. From your really most excellent drawing, we can't deduce the "Z" axis, i.e. the fore-and-aft length of the plates. If it's more than a few inches, you could use multiple pieces of your tubing to brace the plates, or use gussets and tubing.

Confused more than when you started? Good... My work here is finished!

JDK

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JD, father of Quinn, Son of a... Build Log
Quinn the Slotus:Ford 302 Powered, Mallock-Inspired, Tube Frame, Hillclimb Special
"Gonzo and friends: Last night must have been quite a night. Camelot moments, mechanical marvels, Rustoleum launches, flying squirrels, fru-fru tea cuppers, V8 envy, Ensure catch cans -- and it wasn't even a full moon." -- SeattleTom

Miatav8: I'm using an old Jaguar engine mount from Rock Auto (part number C18556), here's a picture



So basically what I'm gathering from you is I want the blue tube to be as short as possible, correct? Right now, I believe it would work out to be around 6 inches or so, maybe a bit more. I can lower the engine a bit if needbe, though I like where it is only because the oil pan isn't sitting below the frame rails (on the other hand, higher center of gravity...)

I'll try and get a picture tomorrow, unfortunately the car is up at work and I"m stuck at home snowed in...


GonzoRacer: I considered using the plates to make a sort of triangle, but I figured they would be to long for that. On the other hand, based on what Miatav8 is saying maybe I should just move the engine down and then a "triangle" would be more feasible. I was planning on gusseting the entire thing anyways, I just didn't want to make my sweet drawing any more confusing

Thanks for the suggestions, I'll get some actual pictures of my setup tomorrow!

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Build Log (not much there yet): http://lotus.reddeth.com
442e frame, 3.4l Camaro donor

The mount you propose look very muck like my original mount. viewtopic.php?f=35&t=6355&start=90. Go to the last 3 or 4 picture on this page. The consensus was that I needed the mounting surface more horizontal. They felt that the tendency would be for the engine the spread the uprights outward. The pictures so the before and after.

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RacerDan
+442 Chevy 2.8
Never be afraid to try something new. Remember, amateurs built the
Ark, professionals built the Titanic.

Your design is actually what I based my idea off of! I actually did make it up to the shop a little bit ago, I'm looking over the engine mounts now. The engine will definitely have to sit lower, which will probably be better in the end anyways.

I'll work up some pictures on what I've got before the end of the day.

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Build Log (not much there yet): http://lotus.reddeth.com
442e frame, 3.4l Camaro donor

Well I feel like I've just had the biggest brain fart for the past few months I've been pulling my hair out over this

Ok, so pictured below are the original OEM motor brackets from the Camaro. Now the whole reason I wasn't planning on using them is because 1) they are different lengths and 2) they are to long (just the brackets themselves stuck out to the frame tubes on either side, no space for a mount below them). At first I was going to cut them down and re-weld them, but I figured "No, they wouldn't be strong enough". Well it's just occurred to me that I'm already talking about cutting and welding my own mounts! Both the OEM mounts and the plate I'm using for mine are 1/4" steel, so it's not like it's an issue of the thickness.

Anyways, whole point being: Can I just cut down, re-weld, and reinforce these OEM brackets rather than fabricating my own? (This would also mean I get to use the OEM motor mounts themselves as well). And if so, any recommendations on how to reinforce them? I have a few ideas, but you guys usually know more than me

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Build Log (not much there yet): http://lotus.reddeth.com
442e frame, 3.4l Camaro donor

I'd ditch the stock frame brackets,utilize the stock engine rubber mount,or utilize some polyurethane material.Set your oil pan to ground clearance you want to run(4-5in.)This should show you how long your verticle(blue line)will need to be.I would use a double tube (trianglated) coming down to plate welded to your frame tubes,to help spread the load.Hope this helps?
Rich

I would suggest doing what I did with my 3800 GM. It's very fast, very easy, and sturdy.

Get some poly or rubber bushings similar to the ones pictured below (leaf spring or 4-link bushings. I got mine for free from the local speed shop that had a box of misc. bushings). Then take the bushings to a steel supplier and get some tube that fits snug over the narrow part of the bushing. Cut the tube so that the inner sleeve of the bushing is flush with the end of the poly. You should now have something that looks like the picture below of the red bushings (but no grease nipple. It's not req'd).

So now using some cardboard make a template of the flat area your engine mounts bolt to. Cut and drill it out of some flatbar. Bolt the flatbar to the engine. Make 4 ears (2 ea side) to weld to the flatbar with holes in them to get a bolt through the polys inner sleeve. So now take the ears, bolt them to the poly sleeve, and then tack the ears to the flatbar on engine (box the ears too to prevent warping during welding and to stiffen them). Remove the poly sleeve and flatbar/ears from the engine and weld. You now have your engine side mounts.

Ok, so now get your engine located exactly where you want it in the chassis with the mounts and poly sleeve bolted to it. Take some large square tube (I used 2x2" 1/8" thick), and use a hole saw the same size as your outer poly sleeve. Drill both sides out of it (dont drill the welded side), then cut it in the middle of the drilled hole. You now have both of your "blue tubing uprights" cut to fit snug over your poly sleeves. Cut the other end of the "tubing upright" to fit to the plate on your chassis and get it welded together. I added fore/aft braces to mine to help triangulate the chassis and take some load off the mount welds. If your "tubing uprights" are shorter there is no need.

Note: this makes for very stiff engine mounts. You also need to be able to drop the engine straight down when installing the engine or the ears will bind. Also drill the holes in the ears a little oversize to the bolt so you can get it in easier when installing the engine. And leave a little room for welding shrinkage. You can also cut the poly bushings and sleeve to make them shorter for packaging.

Hope this helps.
Cory

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Build log: viewtopic.php?t=9291

Cory: That actually looks really good! I think that would work really well too because the 3.4l v6 I'm using has a oil filter in the way of the drivers bracket, and a knock sensor in the way of the passenger, but with your method I could move the mounts forward just bit...

Thanks for the inspiration!

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Build Log (not much there yet): http://lotus.reddeth.com
442e frame, 3.4l Camaro donor

Glad to be of help.
Just remember there is a lot of leverage on that bottom weld. Make it beefy. For consideration, look at how much metal is in those stock engine mounts. And make sure you have a X-member like RacerDan suggests. Mine isn't visible in that pic, but I have one, and some bolt-on triangulation.

Cheers.

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Build log: viewtopic.php?t=9291

My mounts are built exactly like the ones in the original sketch. I used Chevy V8 mounts bolted to a plate on the bottom of the chassis. It has been holding my 200hp six cylinder engine in check since 2003 with no problems whatsoever. The uprights are a 1" x .090" thick tube.

A biscuit like the Jag or a generic early ford mount would have worked as well. I just used what I had on hand.

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Jack Collins

If I'm not asking to much, any way you could get (or already have) a picture of the engine mounts? Would just be nice to see the final construction in practice from a fellow builder!

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Build Log (not much there yet): http://lotus.reddeth.com
442e frame, 3.4l Camaro donor

The mounts drawn in the first post are virtually identical to the CMC motor mounts provided for a Pinto engine. I got them as loose parts when I bought my unfinished build and subsequently sold them off a few years ago. I make no claims to their suitability. I'm just sayin'

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Chuck.

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It is helpful to know how they were used on the XKE. They are vertical with a horizontal bolt. Just FYI.

I suggest a 1x2 tube, extending down to a 2" long, thick walled tube, similar to this Caterham mount.
If there is a protruding lip on the bottom of the mount, cut a hole in the bottom plate across the chassis tubes to clear the lip.

_________________
Miata UBJ: ES-2074R('70s maz pickup)
Ford IFS viewtopic.php?f=5&t=13225&p=134742
Simple Spring select viewtopic.php?f=5&t=11815
LxWxHt
360LA 442E: 134.5x46x15
Lotus7:115x39x7.25
Tiger Avon:114x40x13.3-12.6
Champion/Book:114x42x11
Gibbs/Haynes:122x42x14
VoDou:113x44x14
McSorley 442:122x46x14
Collins 241:127x46x12