You found your expert.

Thanks for updating with an actual reference! I have a copy somewhere.

Duntov hosts the Corvette section here:
https://duntovmotors.com/Corvette%20...wer%20Book.pdf

 

Google pics of Engine block with holes from motor mounts or Engine blocks with motor mounts ripping holes in blocks...IF you can find one post it. If you think you have an engine powerful enough to do it post up the specs...for the torque of your motor to do it you would have to be running 30 inch wrinkle walls and a solid rear axle, and then have e differential and a tranny built to transfer that kind of torque.

Been running solid mounts since 1983 and only switched recently to the new fangled poyurethane only to have those really expensive gimmicks melt

 

Its not about "ripping holes" in the block. IS a crack in a block a problem? It was pointed out that when blocks are honed, torque blocks are installed because of the simple stresses and movement bolting heads down causes.....so to act like the block is this massive, solid object is not really fair. It has eight very big holes in it....and in fact....is more space between walls than a solid object.

And the stresses I am questioning are not about the engine torque.....its abought the stresses introduced into the engine because it is NOW part of the frame....a frame that is known to be very weak structurally and twists alot.

Look....I am not trying to be an expert at this....I simply spent too much money and time over the last two years on this damn 406, to do ANYTHING to risk damaging it. I am very easy on the car.....and there will be no high RPM clutch drops, or drag racing. The Corvette Central rubber engine mounts I bought have been on the car since I restored it....and the 8000 miles I put on the car in 2021 did not rip them apart. So....for me, and my style of driving, I am not interested in risking engine block damage. I am probably over-thinking it......but I also don't believe everything I read......no matter how much forum posters believe they are the experts. ALot of things are said that are simply not correct.

I also don't judge what people say they do on their car.....there are so many different scenarios, configurations and combinations......how many miles were they driven? How much power was introduced or not introduced? What was the quality of the mounts they bought? Does this forum represent everyone whomever put solid mounts on a car.......or is their a bigger picture and more experience. Garage queens don't count either.......whatever they do means nothing to me.

ANyways....enough. I will do whatever.

 

the stress you put yourself through for things that no one has encountered is going to give you high blood pressure.....If racers do it without issues then you dont have to worry about it with the way you say you are going to drive it....its iron and the alumimunm block engines dont have issues.....I would worry more about you screwing up the brake in procedure or hitting a deer. The engine being held rigidly isnt an issue unless it suddenly gets traction or suddenly locks up like using a power drill and it gets caught on the material you are drilling and it twists the drill out of your hand.

I have solid mounts and drive my car like its rented and never had any issue like you are worrying about

 

Like I said the biggest Problem with solid mounts . Is internet chatter..

 

As do thousands of others on thousands of other web forums, and tens of thousands more, who have been doing the same since the things were first put in place by Moroso and Mr. Gasket in the late 60’s.



Using the block as a chassis stiffener when solid mounts are employed is a significant addition to any car where performance is the goal. The car drives more predictable, and there is less movement in the drivetrain where clutch linkage issues sometimes can occur, The negative side effect on the street has always been the added vibrations that can be felt in the chassis. ( I’ve never considered it remotely annoying if it could even be detected at all). Although in this cars case, I’d think it would be one more part of the “experience” if it did. The “ conversation” going on now is another example of “ Then why did you do it”?

If block cracking damage was even the slightest of concerns, and through admission, never intend to drive the car aggressive where any instance of that could ever be an issue.
Why worry about it? And in the same breath, Why add any engine/or engine mod beyond stock where there’d be cause for concern?

In todays litigious world, Lawyers have to remind us that the guy driving the car on the TV is on a closed course, is a professional, and to “ Not attempt this”. You’d think if there was ONE single instance of collateral damage as a result of using solid mounts there’d be one little fine printed line somewhere that reads:

Block damage may occur

Some people’s kids….

 

Ok guys....got it. My last words on this subject are that while many of you are, or believe yourself to be, experts....with possibly many years of experience, I am not an expert, nor have years of experience modifying cars. I been a professional airplane mechanic and pilot for 40 plus years......and THAT has taught me that you can't believe every pilot or mechanic thats been around to be good at what they do, know what they are talking about....no matter HOW many years they have survived. So.....the problem that I have with just believing what a few of you here on this forum say is that I have believed other things people have said on the forums, and it turned out very badly. So.....for me,...I guess I have to decide who I trust,.....and frankly, I don't know any of you personally. My questions are to get some level of answers that I can believe....and why I pursue it. This thread has provided little to go on.....other than a few general statements about solid mounts being used for years......and there is ALOT missing.

I paid a guy to build me a 406 engine with some of the best components available....and he and the "expert" machine shop made SO many mistakes that I had to have the engine rebuilt.....costing me $8000 on top of the original $10,000. Bottom line on that.....I don't believe ANYONE any more about anything. Tough situation for me, and makes it hard to make decisions. I do know that Chevrolet built the car with rubber mounts,....and am pretty sure the C6 I have has either rubber or poly mounts.....so that is a safe bet that they know what they are doing. The only potentional issue I may have is breaking the driver side rubber mount......and if that happens, I guess I will put a solid mount on it. There is really little benefit to me in taking the risk. My car, my decision.

I don't appreciate the demeaning and arrogant responses to what are legitimate questions, but.......its what you get on forums. Some posters have a reputation for that, and so I tend to ignore most of what they say......even if they might be correct. That reminds me.....I can add them to the "ignore list".

 

This photograph of a front motor mount is the best that I can do today.

Actual phopto.

 

Well…I guess he told me.

All web forums are made up of questions, statements, answers and opinions. Somebody asks or says something, then comes the answers and opinions. There are those that rush to offer boundless tips, tricks, advice, and solutions. There are just as many that cruise on by and never say a thing to nobody. Then there’s a few that see the same question one too many times, or consistent opinions offered to someone that says “ yeah but, that’s not what I’m reading/hearing from this “ expert”” that think…If you know your answer, why are you asking a bunch of non-experts then?

And then maybe the conversation gets a little snippy.

If I make a stupid comment, ( and I do), my fault for opening it up to online criticism, and not expecting to get bit in the *** as a result. Participation trophies are for K1 soccer kids. I usually don’t solicit online answers to technical questions myself, always preferring instead to go direct to the source to get my best answer.
However… ( Since I’m being ignored).
The simpler the problem, the simpler the fix. It doesn’t take a rocket scientist to see the benefit to using something that has already proven itself for 5 decades to work.
A steel mount on the pull side is balanced out by the steel mount on the push side.
a rubber mount allows the “pull” side to pull, and the “push” side to compress which allows the mount to fail. That is why there is a redundant lock plate built into the mount. It’s expected to potentially fail at some point.

The steel replacement is proven, widely used, and the benefits outweigh the negatives.
Sometimes a person just can’t see the writing on the wall regardless of how many times it’s written.

To each their own though.

 

I remember when the factory repair was a short length of chain until they changed the motor mount design

 

Ahhhh..... maybe I will just go with the solid Moroso mounts on both sides, rubber on transmission........if my engine gets damaged.....I will expect a check in the mail from each of you for repairs.....LOL. You guys cool with that?

 

Whoa!

Now I'M confused. Informative thread on a topic I've never really given much thought to, and now you guys have me possibly overthinking this. As part of my '69 restoration, I bought polyurethane motor mounts from summit months ago, because why not (see Summit link below)? - since the engine is out anyway., why not replace them...???

https://www.summitracing.com/parts/sum-7731114

So these are crap? Solid is the only way to go? I am NOT trying to start any flame wars here, but as mentioned, I just bought them without really giving it much thought as I didn't think it was a big deal. Also, will these raise the motor up at all and cause potential clearance issues?

 

They way you say you will drive it, how could you possibly hurt it? You arent into burnouts, racing, fast or violent starts...just normal driving correct?

 

Mine were energy suspensions mounts...when I had small block stockish horsepower they were fine. The big blok heat with headers melted them though

 

Correct. But now, with two solid engine mounts.....the engine is now a structural member of the frame. Was it designed for that?.....or just to be an engine?

 

One of the few threads on this forum where I'm more confused about a topic than before I read it. In my case, there was NO confusion until I read through all the posts here. Ugh...

Are poly motor mounts crap (in general) - I bought mine from summit #7731114 (is there widespread issue that they melt)? I suppose I could fabricate heat shields....
Do poly mounts raise engine height at all, causing any potential clearance issues?
What are the overall advantages of poly over solid? - I'm guessing less engine vibration

I'm not worried about mixing and matching solid with poly. It'll be both solid or both poly. I bought poly thinking it would smooth out vibration a bit, and make for a better ride. I'm not talking about Chrysler Cordoba and soft Corinthian Leather riding on a cloud sh!t3. Just reduction of engine vibration, that's all. I've felt what a difference bad motor mounts make when it comes to vibration...

 

Meh, you’ll be fine.
Just take two of these.

Only….you don’t have to call me in the morning.

 

Does that mean you will send me that check for the repair cost if my engine is damaged? I mean....you seem to be confident.....so?

 

I’m so confident that using solid motor mounts will not hurt anything the way you stated you intend to drive this car I’ll go ahead and deposit 18k in your account.

Gimme your PayPal account info.

 

It seems a waste to start my own thread to touch on a topic that is absolutely relevant in THIS thread. I love the humor, but damn, can we get back on topic here? Like what this thread was created for in the first place by the OP? I'm just reading back and forth banter, and pissing contests laced with sarcasm and or/humor...

Some people actually want to learn something here from folks who, from experience and research, can speak with some authority on the topic, and guide the rest of us in our honest endeavor to do it right the first time. While I am not the OP, my questions are in line with his...