Hey Terry... Need some feedback on motor plate engine mounti

[blueovalz]

Well, if I couldn't get paid to drive a Ferrari around a track, then being paid to do your project would be the next best thing. Vibration?.....this is a very subjective opinion, so keep that in mind. I personally do not have a problem with the engine vibration. What is more annoying to me is the driveline vibration, rather than the engine vibration. If the interior is properly assembled with no loose pieces, it will not be a big deal. With the interior parts inside your car that will be installed, I would either make sure they are securely fastened, or go ahead and use rubber mounts. The rigidity that was added to the chassis due to my choice of mounts is nice. Would I do it again with a street car? Probably yes. Sorry for the vague answer, but it's the best I can do. One good thing about having all this stuff solidly attached to the "butt" is the second you foul a plug, or a U-joint starts going south, or any abnormal condition develops, you know it immediately. And this alone has save me a ton of pain.

[Guest Anonymous]

Driveline Vibrations you say... Btw is your tranny solidly mounted too? If so, is it mandatory, or can one have a solidly mounted engine with a rubber mounted tranny? I'd like to delve further into this issue. Btw, the mustang guys swear by aluminum driveshafts, they claim they really cut down on driveline vibrations. Just an idea

[blueovalz]

Driveline vibrations at the current time are predominately tire problems. I have investigated the aluminum driveshaft, and am waiting for a good deal on one. As for your question about the "engine only" solid mounting, my view is that if you only use one plate (front), then this would do little to nothing to stiffen the front end (unless you use a wide bolt pattern out on each side to lessen any flexing around an otherwise small bolt pattern (or a single bolt attachment on each side). This then may help very little. But by using 2 plates (front and back) you have used the rigidity of the entire block to prevent the rails from twisting relative to each other. Then add solid transmission mounts and you then provide a "back bone" or spine running from midway of both axles to the front cross member, which then prevents any vertical flexing. Then to take it to the extreme, I added diagonal braces from the strut towers down to the block in conjunction with a crossbar from tower to tower, and then connected to braces from tower to firewall. Very Rigid!

My thoughts on combining solid/rubber mounts is that they should never be combined. Either make them all solid or all rubber. Solidly mounting only part of a system, and then rubber mounting the rest of it allows the rubber mounted part to move, which can result in the fatiguing of the solid mounting regions (tear out, etc).

[Guest Anonymous]

Hi Terry! Long time no Z. A lot has happened over the past year or so, but I'm back, and this time, I wanna build an entire car from scratch. We're looking at 2200lbs, 400-450bhp (from an EFI 302 ) double wishbone coilover suspension all round, and an adhesive-bonded aluminum honeycomb chassis. The body is gonna be based on the Z's, but the front end will be all new. Your car has been an inspiration, and it will certainly influence how the car is gonna look, with a bit of Viper and 250GTO thrown in for good measure.

I'm doing this for my Final Year Project at Uni, and the great part is, I'll be getting paid to build the car of my dreams

 

I'm still deliberating on whether or not the engine should be solidly mounted to the chassis via a motor plate; where it would become an integral part of the chassis and really add to torsional stiffness. But I'm worried about the amount of vibration that would transmit, and would like a better qualitative understanding of just how much worse it gets. The car is supposed to be a high-performance road car, and will have A/C, power windows, and relatively soft springing. So I don't want it to be too noisy or too harsh. While I know this is kind of vague, I've got faith in your good judgement. Engine is a '98 5.0 with the stock factory balance, but it will have a 280ish degree cam with 11:1 compression (and an engine management system, so maybe we can tune out the lope somewhat). I'd love to hear your feedback on the matter. Thank you