LS Engine Mounts for Original C2 Chassis
 

Wondering if anyone would like to share their experiences or opinions about the reliability and suitability of the LS-type engine mounts on the market that enable the installation of a LS-type engine onto an original C2 chassis. Additionally, what challenges come with this type of conversion, e.g. A/C compressor location/relocation, oil pan, transmission mount alignment, etc. Thanks

You do not use LS style mounts, you use adapter plates to install original C2 style mounts on a Ls engine. Everybody sells these adapter plates. These plates allow the engine and trans mount to land on the original locations on the C2 chassis. There are way too many possible serpentine drive setups to even begin to comment on what fits and what does not, but it is not a problem finding brackets to mount all the accessories. I find the OEM C5 Corvette accessory drive setup to be about the best choice, but you will have to buy an aftermarket bracket to mount the A/C compressor, depending on which compressor you are using.


Regards, John McGraw

All good to know, thanks. My question was really centered on the array of adapter plates out there, understand original-style motor mounts are being used.

there are basically only 2 types of adapters.. you can look at the hole patterns to know which is which.. one type locates the engine 1" further forward than the other. The type that sits further back, puts the rear of the LS within 1/4" of the original Gen I block rear, so the trans will line up best and you will have a little more room in the front to work with accessories and air intake. But you can make either style work.

John,
Question on using the C5 OEM accessory drive.. does the power steering pump clear the original C2 frame and control arms? I didn't think it did.. thus the 4th Gen Camaro accessory drive was a good choice if you want p/s.

As John said, there are many options on these conversions. If you tell us what accessories you want to run, what suspension mods, which trans, etc you're thinking of using, then we can offer more advice.

I used a 4th gen Camaro oil pan, modified the water pump to clear the original control arm on the passenger side, and only run a/c and alternator. TKO600 for a trans. Everybody has some odd ball config or unique parts that really no two are exactly alike. And I'm sure we'd all do something different if we started over knowing what we know now.

Corvette birdcage:
Like John mentions, there are tons of folks making the adapter plates, some work well, some don't.
If their aluminum and 3/8" thick, the engine will likely sit higher than you want. I switched over to 'Vetteworks adapters which are steel, and thinner and that helped a bunch.
Regarding pulleys, A/C, etc: if you're running a stock frame you'll give yourself a LOT more room if you trash the stock A-arms. Savitske Classic and Customs sells SPC adjustable A-arms with tall ball joints that not only improve your car's camber, but make more space for pulleys, and even for radiator fan clearance.
Stock Corvette LS6/LS1 brackets and pulleys can be made to work, but the A/C won't fit into a stock frame. You'll need to talk to Street and Performance about a smaller than stock P/S puley, and you'll need to press the pulley on, with the mounting bolts already on the pump, since there's no clearance to install them afterwards.
You'll also need to change out the water pump outlets, but that's pretty well documented.
As far as the oil pan, just use an f-body (Camaro) pan. It's snug dropping the motor into place, but it JUST clears the power steering. Installing a new pan on an LS motor is super simple.
Assuming you run a 5 speed, the Keisler kit fits pretty well, but like everything else it takes work and patience.
Street and Performance also have shorty headers that will work with the stock Z-bar, if you choose to go that route. I'd stongly suggest you have them tack weld the headers and send them to you like that for a fit-check before you have S&P final welded and ceramic coated.
I'm running an LS6 in my '65. If you need any pictures I can send them to you.

Rick, Thanks much for the input. That's the kind of detail I was hoping for. I would very much invite all pics you would like to send (vette4u@earthlink.net). I take it you added PS too? Thanks

My car already had power steering, so I just used the stock LS6 brackets and pump/reservoir and then once I had the smaller pulley (to clear the A-arms) I had custom hoses to match the new P/S pump to the steering unit.
I have pictures here:
http://livesofrickandlisa.9f.com/photo_4.html

I can send more detailed shots if you need, but there are a few there already that show some of the problems you'll run into.
And just to clarify, I'm guessing you can find a pulley system that'll work with A/C. I'm going to wait until I have time/money to transfer over onto an SR III frame, which I believe will allow use of the stock A/C mounting brackets and compressor. I wanted to use stock brackets for the P/S and alternator for simplicity and reliability.
I lack the space, money, and talent to do the whole rebuild at once, so I broke the project into more manageable phases and just got the car running with the drivetrain, wiring, gauges, etc.
I'm just gonna enjoy it for a year or so and then do the chassis swap and paint when I'm ready. It's a ton of work, especially if you're marginally talented like me, but the LS motors are awesome. I used a Speartech wiring harness which simplified things greatly.

Rick, excellent job on the '65! Thanks much for your insight and pics.

Holley and Qwik sell brackets to mount a Sanden Compressor high which the C3 guys have used. A Vintage air front runner is also an option. Running hoses to the water pump looks to be a little tricky too.

Another thing to consider is if you are running a manual, you need either a hydraulic clutch conversion or mounting a pivot ball for the z bar which must also line up with the mounts.

Rick, great swap :cool:
Which seats are you running?
Did you get the pivot ball and adaptors from Vetteworks?

:cheers:

I used the Z-bar adapter (pivot ball) from the Street Shop. It was a nicely designed/machined piece. I also started out with their adapter plates which were really bad, and ridiculously priced. Too thick for the engine to sit correctly in the cradle, and none of the holes lined up.
The seats are out of a Fiero, and I'm very happy with them. They only required some small, simple plates welded to the Fiero sliders to work and attach at the stock seat mounting positions.

Good luck with your project.
Rick

Hi Rick,
I'm looking to install an LS7 into my stock frame '65 C2 with a Big Block hood that i just bought and don't want to violate the height restrictions to keep the hood. That being said, would you recommend the vetteworks adapters for this application or another manufacturer's adapaters? Can you provide the explanation what & why for your recommendations?
Are you running a stock C2 frame with your LS6?
Can I get some pictures of your set-up and installation if possible?
How much difference in height does the vetteworks adapters have over the aluminum 3/8" thick adapters?
Did you first try the aluminum 3/8" thick LS adapters in your '65 and then have some problems with the location of the motor, if so, what were the difficulties encountered?
Many thanx for you responses to all the questions.
Dennis

Hi Dennis,
I'm still running a stock chassis at this point, and will switch to an SR III frame in a couple of months. I'm running a Tremec TKO-600, and a large part of my reasoning for going to the thinner steel mounts was to improve the drivetrain angle. The floors in these cars tend to sag over the years, and between the engine sitting too high with the first set of mount adaptors and the floor limiting my ability to raise the tail of the tranny at all, I had to do what I could. I never measured the drivetrain angle before I switched to the thinner mounts, but based on measurements afterwards, I think the mounts made about a 3 degree improvement.
I'm not sure if there's any height difference between the LS6 and LS7, in my case the highest point of the motor is the front of the throttle body just in front of the manifold, and the coil pack covers. There's still about 3 inches of clearance everywhere except the reinforcing rib of the small block hood which sits right above the throttle body, there's about 2" there. The stinger hoods don't have that reinforcing rib, so you'll pick up an extra 1" of clearance there.
I'll try to take some detailed pictures over the weekend.
After driving a car as light as these (especially with an aluminum motor, tranny housing, bellhousing, radiator, etc.) with the LS6, an LS7 should be quite the E ticket ride!
Good luck with the project, there's a lot of guys on this forum that have way more knowledge on the restomods than me, but we're all here to help.

Rick

I used the 1 in forward mounts for extra clearence on the firewall and tunnel. Plus my shifter lined up better in the hole. I did have to extend my rear mount slightly. I bought the American Power Train TKO 600 5 speed kit.
My LS 3 G.M. crate motor went right in with the oil pan it came with. My car was a non P.S. so I added the Borgeson power steering box. I used the Billet Specialty front runner pulleys and changed the heater hose outlets. Sanderson street rod shorty headers fit and were around $400.
BTW..I had this car forsale for $98500 but would look at offers in the 80's.

Hi Rick,
Did you end up with a mechanical clutch release mechanism or the typical hydraulic throw-out bearing that most of the C2 owners opt to utilize?
If you ended up with the mechanical throw out bearing, did you use the adapter plate from the Street Shop with some modifications or did you opt for another method (e.g. home made plate? alternate plate? ...etc).
Might you have a picture of what you ended up with?
Many thanx
Dennis

Hi Rick,
Fist, many thanx for your previous responses.
What Bell housing did you use (e.g. original yesteryear small block Bell Housing? Steel scatter shield? After market bell housing?)?
Where did you get the Bell Housing that you used?
Understand you acquired the Z-bar adapter (pivot ball) from the Street Shop, did you have to modify it? If so, what did you end up doing?
You also mentioned the adpeter plates that you were not happy with. How did you remedy that issue? Did you make your own? Might you have a picture that you could send of what you did and how you remedied the issue?
Are you using a mechanical throw out bearing/fork at this time and is it working OK?
I understand the questions are many however; if you would be so kind to provide a response adjacent each question it would greatly be appreciated.
Many many thanx in advance,
Dennis

Hi Dennis,
The bell housing I used was aluminum, and also from Keisler (now Silver Sport). I was pleased with the accuracy when I measured it for alignment for putting in the Tremec. I also got the flywheel/pressure plate/ clutch from Keisler. I am using the mechanical clutch linkage, I prefer the feel vs. hydraulic. Initially the travel was marginal to fully engage the clutch and still have adequate clearance when the T/O bearing released. I found a significant improvement by using a different Z-bar that improved the travel of the T/O bearing arm. The Z-bar adaptor from Street Shop worked fine, and placed the stud nicely in-line with the stock frame location.
I used thinner steel motor mount adaptor plates from 'VetteWorks. They fit very well, and allowed the motor to sit lower at the front
I'll take a few pictures of the and send them to you. Please PM me with your e-mail, I still haven't figured out posting pictures.

Rick,
Again, thanx for the info.
Gonna go the route of your recommendation and procure a z-bar adapter from the Street shop, if they ever call me back or answer e-mails.
Where did you get the "different Z-bar" that improved the travel of the T/O bearing?
What make, model, year, of car Z-bar did you finally use. Would like to try and use this same component should I run into the same anomaly.
Again, many thanx for your time and knowledge.
dennis

Hi Dennis,
For the throwout bearing travel to be most effective the angles between the Z-bar arms and the pedal pushrod (top) and the T/O bearing pushrod should be travel through (roughly)the 80 to 100 degree range. With my stock (small block) Z-bar, and lined up with the lower pushrod, the upper pushrod was "over center" with relation to the Z-bar and I was losing horizontal travel.
I was getting ready to cut the Z-bar and weld it with a larger angle between the upper and lower arms. I live in San Jose and there's a good corvette parts place close by (Corvette Clinic). I took my Z-bar to them and they brought out a number of different versions. On mine the angle between the two arms was approx. 130 degrees, one of the ones they had was an angle of approx. 160. It made a significant difference.