[64speed]

I have a Heim joint turn buckle that when threaded almost entirely out is the perfect length to run from my head to the frame rail. I would have to weld a tab to my frame to mount the other end to but that’s easy enough. I also have a length of chain with the eyelets that is the right length with just a tiny bit of slack that I can wrap around the frame rail and bolt to the head. The goal obviously is to save rubber motor mounts and avoid going solid. If I do the Heim joint it’s solid the rubber is absorbing the engine vibration but it is allowing for NO movement of the engine. It does however look professional. The chain is obviously the easier of the two to do and it allows for some rocking motion to not put stress on my motor mounts which are only the two bolt kind just more likely to crack the block if I ever got traction so I’m told. So what’s the consensus? Turnbuckle or chain? My great big billet accessory drive hides either one so while the turnbuckle would look better the reality is unless your really giving the car the once over you’re never gonna see it. So which would you choose?

[ponyakr]

Have used both. Both worked.

[64speed]

Originally Posted by ponyakr

Have used both. Both worked.

Did you find that having the chain with a little slack to allow the motor to move a bit was better or was it pretty much a wash. I have heard horror stories of the two bolt motor mounts and cracked blocks with solid mounts.

[STEELCITYFIREBIRD]

Chains stretch and can look crude.I would use a strong turnbuckle...adjustable, wisely/well mounted. ....Travel limiter, not eliminator.

[HWYSTR455]

I've not used 'torque straps', ever, there's no need to for under 700hp IMO. The engine mounts have built in limiters/safety limiters that work fine. Never had one fail, and I abuse the crap out of my stuff.

Once that strap in the mounts became mandatory, the 'old racer' trick of using a chain or whatever went out the window.

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[64speed]

Originally Posted by HWYSTR455

I've not used 'torque straps', ever, there's no need to for under 700hp IMO. The engine mounts have built in limiters/safety limiters that work fine. Never had one fail, and I abuse the crap out of my stuff.

Once that strap in the mounts became mandatory, the 'old racer' trick of using a chain or whatever went out the window.

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There are numerous posts on here about motor mount failure. The motor mounts we are getting now are cheap far east pieces and they just dont hold up. My friend that has a motor built almost exactly like mine has had two fail in the last 6 months both on the drivers side.

[Tom Vaught]

Originally Posted by HWYSTR455

I've not used 'torque straps', ever, there's no need to for under 700hp IMO. The engine mounts have built in limiters/safety limiters that work fine. Never had one fail, and I abuse the crap out of my stuff.

Once that strap in the mounts became mandatory, the 'old racer' trick of using a chain or whatever went out the window.

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1) If you are trying to keep the engine from rolling over like the Chevy engines did and caused the carb linkage to keep the throttle open, then the above mounts do exactly as they are designed. Chevy engines for the most part did not use throttle cables, Pontiac Engines do.

Same deal for solid mounts, they "lock" the engine in place somewhat. But I also see more of an air gap that I would like to see in the mount in the picture. This "gap" gives the engine block a running start before the engine mount, above, tries to stop the movement.

I have personally used the Mounts in the picture, used a chain, used a cable, and finally a 3/16" thick "strap" that goes from one of the bolts on the power steering bracket (cast iron mount) to the vehicle frame.

The "Strap" has a machined slot that allows the engine to run without transmitting sound to the frame, (about .060" clearance before the engine movement is stopped).

It makes no noise like a chain, stops the engine movements in the strong part of the block: (the front bulkhead), and is invisible to most people looking at the engine. (It looks like another support strap for the Power Steering Pump.).

The Mount above, in my opinion is barely adequate for a stock driver, and does nothing as far as eliminating stress to the #2 and #3 Main Webs in the block. They do crack there, at times, and maybe because of the stress that the block sees from High Hp and a POS engine mount design.

JMT

Tom V.

[Sirrotica]

I've never used a chain, never liked the look of it. If you buy a turnbuckle with a large eyelet on it (say 1/2 inch hole) you can put it over a 3/8 bolt with washers, and adjust where you want it to make contact, if you feel slack is needed.

I tighten the turnbuckle so it's just barely under tension, there is no slack and run it. I've never noticed any vibration transfer in any of my cars. The motor mount is still able to do it's job, and it doesn't take anywhere near 700 HP to break Pontiac motor mounts, especially the early types that aren't captured with a steel shell. They have all been cheapened with crappy rubber, and lighter gauge metal than the OEM parts were from GM.

The 69 GP in the third picture in my signature broke the mounts with 450 HP, 8 inch tires, on clay dirt track. New mounts would break in 2-3 weeks. I used a turnbuckle on either side because of deceleration forces, and never broke a mount for 2 years after installing them, until the car was retired.

The turnbuckle solves the problem and it uses the cylinder head to transfer the torque limiting to instead of the area of the block near the oil pan rail. That area isn't terribly robust and can fatigue over years of abuse. For ten bucks the problem is solved..…

[rohrt]

Instead of Chain or turnbuckle I wanted to use plastic coated aircraft cable with crimped ends. I haven't looked into it yet to see it would be practical.

[Sirrotica]

Originally Posted by rohrt

Instead of Chain or turnbuckle I wanted to use plastic coated aircraft cable with crimped ends. I haven't looked into it yet to see it would be practical.

FWIW, I had thought about the same idea, I hadn't pursued it further yet though. 1/4 inch cable would be plenty sufficient from the preliminary stress specs I have seen. It would probably be more stealth that chain or turnbuckle is.

[Formulajones]

That's similar to how GM did it as far as the cable goes.

They had a recall on Chevrolets in late 69 or early 70 for broken mounts. Even on little 290 HP 302's, so it doesn't take a ton of power to break one.

GM simply used a small cable wrapped around the upper control arm bar and attached it to a simple bracket that bolted to the exhaust manifold. Cable was looped, crimped, and a removable pin going through it. Actually sought after today for those restoration purists looking to "day 2" their rides, so they bring a little money when you find one.

[JUDGE3]

Originally Posted by rohrt

Instead of Chain or turnbuckle I wanted to use plastic coated aircraft cable with crimped ends. I haven't looked into it yet to see it would be practical.

Always used this. works great.

many state a solid motor mount on the drivers side, stock mount passenger side works great also. think I may go that route.

[78w72]

i use a chain from the front of the head down to a bolt/nut in a hole i drilled in the frame, very hard to see when everything is installed. has about 3/16" of slack & has worked great for ~5 years & lots of street abuse & at least 40+ low 11sec drag strip runs at 120+mph.

i also make my own improved version of a mity mount for the drive side mount & between the 2, i have yet to break a mount. but i agree the aftermarket mounts are crap & lots of people with higher power engines & good traction break them frequently. i have a 2nd gen firebird so the mounts are a little different & dont have that strap pictured above, but a limiter of some sort is a good idea at this power level & cheap insurance... when a mount breaks it can cause more damage than just the mount.

also with the chain there is no noise at all... & if there was a little noise its impossible to hear over the engine or while driving the car.

[RocktimusPryme]

Ive considered a cable too mostly for aesthetics over a chain. I just don't want to buy the crimping tool for one job.

[Rocco Testa]

I too used the turnbuckle, as for the mounts. They are real cheap, We broke one on an engine run in stand.

[Tom Vaught]

THE FACTORY MOUNTS WERE OK IN THE 60S/70S. Caps for a reason

The modern stuff is for the most part, pure chit. Offshore guaranteed.

The poly stuff may be ok from a few manufacturers, for the most part again, not what I would put on my car.

If you have access to the Crimping Tool, the Plastic Covered Cable is probably the cleanest installation.

Tom V.

I agree with you on a lot of your posts, HWYSTR455, but have to respectfully disagree on this one.

[sdbob]

I used an aluminum turnbuckle in 1970,on my 63 GP,421.it worked until it stretched so use steel.

[HWYSTR455]

That piece is thick plate steel, and like I've said, never had one fail, even with many miles/time. Even if the rubber part fails, that steel won't. But do as you please.

I know I was over 550HP, have replaced them just because I've had the engine out, and used the Anchor ones. Now I did have some issues with fitment, but buying from NAPA that has been resolved. And I don't grandma my cars.

Show me pics of the failures. Failures with that strap broken, not just ripped or rotted rubber.

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[hojs69]

Solid mounts for decades; older Indian Adventures brand.

Just throwing it out there.

[HWYSTR455]

The biggest factor I've seen over time that makes the rubber fail in GM engine mounts? Leaking power steering pumps, boxes, and valve covers.



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