jhyneman

Has any one actually put a frame on one of these cars? I am not talking about putting subframe connectores on. I am talking about a real frame. This all started when I installed a diesel engine in my car. Because the vibration everything rattles. Gets 40+ mpg and looks great but I think that by frameing it like an old A-body I could get rid of alot of vibration.

joshh44

you put a diesel engine in a F-body?

jhyneman

Yes!!. I have a few upgrades I would like to do to the diesel but I need a stronger frame to do this also.

joshh44

wow. just wow.
i would add subframes to it. should help with any twisting of the body.
maybe at a strut tower on the front of the car.
like shown in this photo

the bar going across the engine. that should help as well.
or its shaking madly because you put a diesel in an F-body lol. im not to sure if there is a cure for that or not..

ryan91rs

iTrader: (1)

try using the softest motor mounts you can find. and diesels today can get so much torque it's crazy. If they did not sound so bad i would do it.

Sonix

iTrader: (1)

A 3.9L diesel? What's the point then? You want economy, buy a Tercel or a Tempo...
I digress though, that's not the point of this thread.
I highly doubt the car needs a frame due to the torque that "monster" of an engine makes. Many other members on here run much more torque through a supercharged big cube gasoline engine. As mentioned I think it's the mounting. Speaking of, how is it mounted in there? Normal rubber engine mounts, motor plate, etc? Got a picture of this? I think that'd be hilarious. I think you're one of maybe 3 people who has ever been crazy enough to do this to a 3rd gen - ever.

ryan91rs

iTrader: (1)

wow just noticed the tiny motor. i'll leave my comments to my self except to say...... WOW! thought it was bigger than that

jhyneman

I thought about strut tower braces but the engine is to tall to fit after market ones on. Because the engine compression the firing hits so hard that it causes a strong vibration. The vibration actually vibrates the t-tops in the car. You cannot see out the mirrors. By framing the car and installing frame isolators/ body mounts I am thinking that this will isolate the vibration and keep it in the frame instead of transfering it to the body. I am already using the softest mounts available for this engine.
----------
Economy isn't what I am after I already have that. I am planning on cranking up the hp to 300hp and 700 ft/lb of torque. I am mainly conserned about all the vibration that is occuring. Vibration causes premature failure of parts and welds. I have seen windshields crack with these diesels especially once the hp is cranked up.

Zipdrive

You might as well get a glass body and make a funny car out of it. It would be easier. Taking a uni-body apart to "frame it" will be difficult. You are much better off correcting the source of the vibration (currently the diesel) than band-aiding the rest of the car. A good diesel should not vibrate more than a gas motor under load. At idle, the mounts are going to show the difference. Get or make a set of SOFT rubber mounts. That should remove the vib problem.

Sonix

iTrader: (1)

The durometer of the mounts is a tuning aid. Softer != better. You've tried soft, try medium. Harder will transmit more, but the soft ones may be moving too much and basically "bottoming out".

I have already mentioned I don't entirely agree with your choice of engine, and personally I don't think you'll get nearly that kind of power output, but since I'm not a specialist in diesel i'll shut my trap. Aside from that, you have an interesting and fun problem, so lets see here.

If you have a chop saw, pick up some 1" sch 40 pipe and add some custom braces. If you brace the engine solidly to the engine bay it will indeed shake your teeth out and shatter your windshield. Look at additional supporting members, with rubber ends. ie if you still use stock style clamshell type of mounts, maybe think about additional braces, but with rubber ends.
I'm imagining a steel cable, connected to the engine, and bolted to the frame rail, using BIG rubber o-rings as washers, to absorb the shock/vibe load.

Frame isolators and body mounts are a good idea. Also if you have a welder, weld up the pinch welds and other factory 'quicky' type of welds.

naterman35

I think its cool that its in there... something you don't see everyday.

Anyway What i say is you put in SFC first thats a must. But i think i would look into Diffrent ways of Supporting the engine... With Motor mounts its mainly bolted at the bottom ish of the engine... What abotu fabbing up a way to put a brace from the top end of the engine to the frame using rubber ends... Maybe it will aid in letting the top of the engine nto rattle as much.

MorrisL03

Just wanted to chime in that I think its BAD *** that you did something out of the ordinary and threw a diesel motor in a 3rd gen. torquey little motors and popular around here with the off roading people.

naterman35

I Love things liek this... Over on MIFbody.com theres a guy whos making an 11sec v6... NA running nitrous... Its a trick little setup..

86v6CP

Due to the unique nature of your swap, Photos are required and demanded. This has got to be the most interesting swap I've heard of yet.

joshh44

photos are a must.

jhyneman

Well here are 2 pictures of the car and the engine in the car.

3.1EyeCandy

iTrader: (3)

wow. I don't know what else to say. Did you keep your A/C? Looks like it...

slow_90firebird

sick! You got any videos of the exhaust? Also, how does the emissions work for a gas car with a diesel in it? Do you have anything done to make it soot? Injectors and a tune or something?

I wouldnt frame the whole car either. I would get a good set of SFC's and try some different motor mounts, and a tranny mount. Also, get a wonderbar and you can custom fab up yourself some sort of STB. All that will help.

If you really want to invest the time to remove the whole interior, and repaint, you could stitch weld the whole car. This isnt an f-body, but you get the general idea.

ryan91rs

iTrader: (1)

i still agree with others. you need to isolate the vibration at the engine and tranny mounts.

loneroad

iTrader: (3)

have you thought of using dog bone motor mounts on the top sides of the engine. You should be able to find a set of ones in a junkyard. fab up a plate to the strut towers. Im pretty sure that 80s models gm front wheel drives had some pretty stout ones...cavaliers and so on

Sonix

iTrader: (1)

Ah, loneroad, that's even better than what I was thinking. That'd be a good idea. Maybe on the upper side of the engine, one per side.

That's sure an oddball looking engine. What is it exactly? cylinders, turbo, induction...?

joshh44

if i were to do that. i would try to find a big diesel engine from a 3500 chevy truck or something. keep it all chevy
i would love to see a video of it running and what not

robertfrank

iTrader: (27)

a duramax in a thirdgen.....that would be a HARDASS setup, especially if it was beefed up!

loneroad

iTrader: (3)

[quote=Sonix;3594142]Ah, loneroad, that's even better than what I was thinking. That'd be a good idea. Maybe on the upper side of the engine, one per side.

exactly 4 point motor mount should stabilize the motor and keep alot of the vibration down

customblackbird

iTrader: (15)

most of the newer front wheel drive cars, subaru, chevy, basically anything wit a 4cly or 6 in it from the 80's till now have top motor mounts, i would also suggest that as a good mod for your problem. i would also increase body stiffness bc diesels are torquie lil F*CKS. SFC would help especially with transefering tq to the rear wheels.

as far as doubting 300hp from diesel... u must be kidding, diesels are making 500-700hp now no prob, BANKS gets them to over 1000hp now. stock they dont, now its like 300hp but on a stock truck with a turbo diesel... they just give it a tune with an exhuast, and a cold air kit and they can instantly increase 150 hp with just that. not to mention insane TQ #'s. bullydog makes some stuff for diesels etc that can give u numbers like that. i see it on that show "trucks" all the time

Props to u jhyneman!!! very diff and with 40mpg i cant BlTCH at u lol, too bad diesel gas prices are more $$ than reg gas used to be cheaper and thats why everyone bought diesels.... the gas companies were waiting lol

xpndbl3

iTrader: (5)

He shoved in a tiny diesel, not a truck diesel engine, Look into how that donor vehicle mounted the engine and go from there to remove vibration. If not, deal with it, all my diesel work trucks vibrate, are noisy and stinky.

86WS6

iTrader: (1)

Vibration is a hallmark problem with diesels. 16:1 compression ratio, in your case 4 cylinders... We did a 6 cylinder Cummins conversion into a Chevy G30 Crewcab 4x4, and it vibrated like crazy, especilly at idle. Interior noise was also a problem. Softer motor mounts did help some, but eventually the truck begin to develop stress cracks in the sheet metal. Worked on a Winnnebago 30 foot with a Duetz Diesel conversion, and it had the same problem. Unbelevable power and economy, however it rattled so badly, that the fins in the refrigerator would sing. Also with a diesel, who cares about HP. It's all about torque. Cool idea though! Love that 40 MPG.

MorrisL03

was searchin around on these motors and found some Info that might be helpful to you...If not then good luck on the build. Keep us posted!

http://www.dieseltruckresource.com/d.../t-104773.html

jhyneman

To give a little history on the engine. This is a Cummins 4BT 3.9L engine rated at 105 hp and 370ft/lb of torque. It came out of a Chevy P-30 van. The engine was part of a GM/Cummins repower program that started in 1989 and ended in 1992. This engine was mounted just like it was in the truck with the exception of the fact that I used softer mounts. I will have to go to the drawing book and start figuring this out. I don't want stress cracks throughout the whole body. That happened in my 89 Ram with a Cummins 6bt. Ended up replacing the cab. I am thinking about putting the car on a rottisseri and having the entire front section and under body spayed with line-x epoxy bedliner. That did a wonder on the 89 ram. Quieted it up and made it rock solid. no more cracks.

86WS6

iTrader: (1)

Was that one of those Fritio Lay vans? They were nice conversions. The 4bt's were mated to a GM SM-465 4 speed via a custom bell housing made by Cummins. The 4bt's and the 6bt's have the same bellhousing design. That's how we put the 6bt in the Chevy Crewcab. We used a Cummins bell housing, mated to an GM SM-465, mated to a US Gear 2 speed, and then the GM transfer case. I think that part of the vibration issue's were caused by the nature of the transfer case mounts, nearly solid with hard rubber bushings. I am surprised that the F-body can bear the weight of that 4bt? The 6bt was so heavy that we were running a Dana 80 axle up front.
How would it work to weld additional framing to the existing car body to increase it's structural integrity? Kind of like the way large truck frames are braced with 2 inch gussits, and flat bar below or above the exisiting structure. You might be able to weld flat stock to the bottom edge of the existing sub frame, with subframe connectors added.

jhyneman

yeah this came out of a Frito's truck. The 4BT weighs the same as a bigblock chevy. I used a triple rubber trans mount. like would have been used on the trucks. I was thinking of semi-channeling the car to sit a frame from a wagon or a s-10 under it and get rid of that usless trunk space I could probally gain about 6 inches in the back trunk for usable room. Go with a 4-link with air bags in the rear and maybe airbag the front. I think that I could get alittle more tunnel clearance and get the engine off the firewall alittle more. This would cut down on the vibration. Greatly improve the handling. Add alittle more clearance on the back for bigger tires, and the airbags would be able to drop the car so it would look stock.

To answer a couple of other questions. The car doesn't blow black "YET" Emissions were actually cleaner than the stock gasser engine. In the engines stock configuration it runs about like the 2.8 that I pulled out of it. I installed all the heavier springs upfront and heavier tortion bars.

Mathius

No, because every time someone asks about it. Everyone jumps in and says there's no reason to do it because you can add subframe connectors, and you can add strut tower braces, and you can do this, and you can do that. Because those things are all the same as building a frame.

Mathius

jhyneman

I am not sure if I get the vibe of frustration, irritation, or sarcasim. Maybe all 3. Mathius, give me your imput on this topic of discussion. How do you feel a frame would act on this car and your approach on this problem that I am facing.

Sonix

iTrader: (1)

Exactly, lets make fair comparisons alright? This diesel making 400+ HP is BS anyway. Thats magazine monkey spank in my opinion. Diesels don't rev high enough to make real HP, they make TORQUE, which in itself is a fun thing, but lets not throw horse manure around and make unrealistic HP claims eh?

That's about what I figured in the beginning, 100HP, performance similar to the original 2.8L but with an extra 400lbs or so. Not what i'd do to my performance car, but to each his own. A BIG diesel might work, but still not what i'd do to my performance car, I like to rev a bit higher than 3500RPM...

I think reinforcing ribs on the underbody sheet metal might be a good idea.

Well, good luck on your oddball idea, certainly is unique. Keep up the pictures and specs though, if nothing else it's definately an interesting trial.

rmmstnr

Dang! I wanted to put a diesel in a 3rd gen. I suppose I can still do it, I just hope it isn't as boring as tossing in a 350 or 383 by then (waiting for the new GM turbodiesel, 4.5l). Well, I applaud the bravery of announcing that you swapped in an engine that's neither of the two mentioned above, or even a V8! Everybody's been real good-natured about it.

Yes indeedy though, pics! I love it when stuff like this comes along on this site! Oh, good luck damping that vibration, being a 4 cyl that operates at slower speeds, you'll have trouble with that. If you do somehow get a frame on there, so much the cooler!

ross

Man I hate to say it but that motor has always had a bad vibration proublem hell thay shake so bad thay will start droping off bolts and such the 6 bt was much smother running. You can try and bump up the idel a little to smooth it out but its going to thump into gear.

jhyneman

Yeah your right I already tried bumping the idle. To hard to hold the brake. Actually until I hit about 1200 rpms the hole car shakes and rattles. Even the t-tops are rattleing. So is the rear hatch. That is why I want to frame the car instead of subframe it. I found some great oil/gell mounts that work great as body mounts and really isolate the vibration. "I think".

86WS6

iTrader: (1)

Your idea of a separate frame to isolate vibration problems will probably work. Depends on how much work and how much money you want to spend. You could take a frame from another vehicle, and mount the engine and running gear on it, then mount the body on top of it, which will isolate much of the vibration from the car body, but you will have to increase the ground clearance to do it. You probably won't find a car frame that is strong enough to handle the stress, so a truck frme will probably be your best bet. I like the idea of diesel conversions, and am considering a 4bt conversion in a 4x4 Ramcharger, but in your case rather then modify the car to extreme to fit the engine, I would consider another type of diesel engine, that might be more compatable with the dynamics of a uni-body car, like an automotive diesel.

car_fixer

you might try adapting some hydrolic engine mounts out of like a mercades diesel, they do a pretty good job of isolateing, also the earlier ones used a small shock by the mouts when they used plain rubber mounts.
Alot of the vibration may be comming from the trans mount, if you could use a crossmember with bushings in it in addition to the rubber trans mount, that may help, i think fox body mustangs used trans crossmembers like that.
as far as full frame replacement retrofit etc. yes it has been done, full tube race cars arent uncommon, but the idea with them is a stiffer platform, so using some chassis like a s 10 would allow you to isolate the chassis somewhat, but it would still need mounting to restrain the engine. there is a local guy that has a camaro on a blazer chassis, I might be able to find him, and maybe get some info on it...no promises though.

or switch to a vw engine, those tdi engines are smooth, and plenty of mods available too

customblackbird

iTrader: (15)

hey sonix http://www.bankspower.com/ thats alot of monkey poo to me huh... lol does that say tuners.... for 110 hp/164 ftlbs of tq from a tune??? yes it does. they also sell performance parts for 1.9L VW TDI diesels as well as 2.8L jeep liberty diesels. tuners are worth 20hp and 35lbs intakes are worth 10hp and 16lbs yadda yadda yadda. he has a 3.9L he should def be able to get more than 200hp outa that and insane tq. maybe u should think about what u say before u write it down. they have diesels in the 7s making over 1000hp. now that ur done with the shinanigans.

its gona be real hard to install a frame with the car due to the cars makeup and how the cars are usually built around the frame with sunken in floor pans etc. inorder to do that on a 3rd gen u would have to cut into the floor pan and notch it to fit the body into it, the fram would then be in the car about 6" from the bottom of the floor and into ur crotch. then u'll have to find a way to mount it.... slapping a frame onto a 3rd gen is gona raise the 3rdgen since the bodies gona be sittin on the frame unless u knotch it as i stated which u dont want to do.

what i would do is build a tube frame for the car. u will just do the basics but i would cut and measure everything and tack it do its basically assembled to the floor of the car but not attached. mimmic the stock stub frame mounting points etc then just lower it off the floor of the body and weld. the motor mount etc will have to be done outa the car where measurements can be taken etc but u get the idea.
the tunbing will help with weight/strength/ride height. still its gona be huge pain and prob a good bit of money. but if thats what u want. thats something i would look into.

86WS6

iTrader: (1)

Have you thought about converting your car to a stick shift? You mentioned the vibration being worse idling, it's probably transfering some of the vibration from the engine through the automatic transmission when idling in drive. Then you could set the idle speed of the engine up enough to smooth it out some.

jhyneman

Hydrolic engine mounts might work. Did they make them for angled usage or for flat only use. The mounts that are on this conversion were adapted from an late 80's early 90's ram diesel. I had the gas mounts in it and the vibration was worse. I could possibly see adapting the hydralic mounts for the transmission. That would soften it up.
Now the thought of converting it to stick. I have thought of that but with a max of 2500 rpm? Have you ever raced a diesel. Sticks with a diesel are fine for towing or economy, not racing. I have a 06 ram diesel with a 6-speed that is chipped and I can't shift it fast enough to even get a little wheel spin.

Mathius

I'd have to say all 3. This place has so much traffic and so many people here with the time and money that they put into their cars and yet somehow they almost all turn out the same. 4th gen interior, big badass built motor, subframe connectors, strut tower, and some hot rims.

In fact, the fabrication forum itself is only a few years old compared to the rest of the site.

But let me address the frame thing...

First, in your particular instance, I can't say honestly that I believe it would be cost effective for you to build a new frame for your car, vs. taking some of the other options mentioned in this thread. I'm not going to try to tell you that those other options won't work, or that they won't be cheaper. But I found it irritating that everyone just dismissed your question and just starting offering other options.

What are some benefits of putting a frame on this car, besides just the "wow" factor, or asthetic reasons?

First off, it would be stronger than adding subframe connectors, and there's a good possibility it could be made to ride better.

Unit-body cars, or unibody cars (both terms are correct) were designed without a full frame. They were designed to be lighter, and engineered to act a certain way. Stiffening up the chassis isn't always a good thing when the chassis was specifically designed to flex a certain amount.

Full frame cars are built with body bushings for a reason.

Second, there's the option of easily addressing other suspension options. F-Body's were designed with a strut tower setup, front and back, and while it is possible to change those suspensions, it's pretty difficult to do it without making your sheet metal a hack.

Strut towers ride nice, but they take up a hell of a lot of room in your engine bay, and hacking away at those parts just weakens your whole front end. One option is a tube frame to support the strut towers.

Third, you start with a clean canvas. Adding subframe connectors, and strut tower bars are fine.. But you're really attempting to improve on something that was designed by someone else, FOR something else. If you build the frame yourself, its engineered and designed how YOU want it, FOR what you want it.

In all honesty? I personally just find the idea of adding a frame to an f-body to be an exciting prospect, mostly because of the puzzle involved in doing it. It would involve a total redesign of the underbody of the car. Where does the gas tank fit? How does it effect the hatch setup? Would you have to make the entire car larger?

You could go a race car route, and do a small-ish tube frame, with an incorporated roll cage.

I wish people would consider things before they just threw the idea out the window.

Mathius

86WS6

iTrader: (1)

As for the manual transmission, I believe that the slow shift problem is a more a matter of the type of transmission you use then the diesel engine. I have an F-350 Powerstroke with a six speed, and it is just like the transmssion in your Dodge truck. A truck transmission can't be speed shifted, but they are good pullers. The SM-465 4-speeds that they used in the Frito-lay P-30's are made just for pulling only. First gear is not syncronized, and second only up to about 20MPH, depending on the diff ratio. One of the car type manuals may have better shifting charactersitics which will help the situation, however with the limited RPM differential of a diesel, you will have to shift more often then a gas engine, which will probably slow your times down some. Bt4's used in commercial applications have a large counterbalance on the crankshaft to dampen vibration. I wonder if there could be a way to balance your engine?

Firebird_dave7

I dont care what the ones who are against it say im all for originality and that it awesome good job!!

As Far as Frame/Chassis i would get SFC's, a Wonderbar, Fab up a strut tower brace, Drill 2 holes on each Subframe rail and make a Cross(X) Conect them and you will be pretty rigid. Also Poly bushing all the way around, and you can always air shock the engine mounts. PM For more on that if interested.

jhyneman

Mathius Thankyou for your imput. I appreciate it alot because you are addressing the advantages of a frame that I have been trying to get across.
While beefing up the uni-body frame and chassis is great for a gas engine it will never really isolate the engine vibration because the k-member is bolted directly to the subframe. The third gen cars are not like the first and second gen cars. the whole front subframe on the earlier generation camaros and firebirds were mounted rigid by bolts to the body, not a fully welded subframe structure. They were a much more stout and sturdy platform. They used heavier steel and the cars themselves handled in my opinion better. Having said all that some of you may be thinking well then you should have used one of those bodies instead of a third gen. Yes I could have done that but I like the body of the the third gen the best. Because of body reasons I chose the third gen. Because of this choice I don't mind cutting, modifying, and fabricating on my car. I had to fabricate alot of parts to mount this engine in the car. I just don't want all of my time to be rendered useless because I failed to accept the fact that this engine is a rattly diesel, and like Ross said this is a rattly diesel. The hood on this car is not just for looks it is because the engine is so tall. I didn't like what I could buy for these cars so I made a cowl hood for this car from scratch. I started with a drawing and a imagination.
More than likely I will put a frame on the car. It won't be a round tube frame. The strut towers will go away and the rear suspension will be changed. More likely something like a 4-link. The Frame will probally resemble a a-body frame or a corvette frame. The body will have not need to be stretched but the interior will more than likely be more roomy. because that huge hump behind the back seats will go away and I am going to achieve a nice big trunk. Right now I need to get on the drawing board and figure out how to achieve a way to frame the car.

Mathius

You're pioneering into new territory here. Aside from some race car applications, I don't think anyone has put an actual frame on an f-body that I've ever read about and I've been researching, driving, wrenching on these cars on and off for 10+ years.

If I thought you were going to keep the factory suspension, I would say the easiest way to run the frame would be to follow the factory subframes as much as possible, then cut them out, weld steel back in to re-enforce the body where you removed it and create body mounts, then bolt up your frame there.

But since you're talking 4-link etc.... I could be wrong, but I think it might be best if you welded some tubing horizontally perpendicular to the body to re-enforce it (temporary) and then just cut all the sheet metal out of the floor of the car from front to back. Ran your frame how you wanted it... ran your exhaust, fit your gas tank and spare if you choose to have one, and then make your own floor to put back in the car.

Since this is such a huge project anyways, you might even want to consider removing the dash, and cutting and and smoothing the firewall while you're at it.

Another thing to consider... again, this is such a huge project, but adding the full frame would definitely make the chassis as strong as possible (in a stock sense). You could do some mods that other people have only considered, like a Targa top, or Suicide doors.

Oh, lastly, and more practically... if you're going to do your own frame... make sure you take a close look at incorporating things like an x shaped crossmember to stiffen up the center of the chassis, and a drive shaft loop.

Go to protouring.com and look for some information on John Parson's Nova. He posts there regularly. Popular Hotrodding did at least 3 articles on his car that I know of. The long and short of it, is he built a G3 Nova in his driveway with nothing more than help from guys he found on protouring.com.

Mathius

jhyneman

now we are talking. I am getting some ideas on the how to fabricate this frame. Here is what I am thinkingI am thinkin of taking 2x3 rectangular tubing and following the channel around the floor boards. Removing the front subframe completly and using something that would resemble a front nova clip but instead of bolting the clip to the body welding the clip to the 2x3 frame. then on the back get some rear frame rails from jegs and welding the frame rails to the 2x3 frame. This would allow the structure for my 4-link.
This corvette frame is what I am thinking of.

AlkyIROC

Couldn't find any diesel Camaro's on Youtube but found a 3.9 Cummins diesel rat rod

http://www.youtube.com/watch?v=mVlov_t4fjg

RebornFromAshes

Did you think about trying to isolate the K-member from the rest of the body? That would allow some of the vibration to be transferred to the front tires without transferring it as directly to the body. If that is the whole point to building a frame for the car then it will be much easier to modify the connection point between the K-member and the frame rails while accomplishing a similar effect.

How much does the engine move at idle? If it moves a bunch on the soft mounts maybe you need to build a more complex mounting system with two stages of rubber isolators. That should allow more tuning of the dampening as well as providing dampening to deal with both low and high amplitude vibrations.