biohzrd Posted July 1, 2002 Share Posted July 1, 2002 i was debating mounting my engine with plates instead of mounts. i figured it would allow me to place the engine pretty much anywhere i wanted and would also help in the overall strength of the car by acting as an additional cross member. let me know what ya'll think. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 1, 2002 Share Posted July 1, 2002 I have a 73 Celica with a 360 dodge in it and let me tell you about motor plates, they transmit vibration and noise almost as well as a stethescope. You can't beat them for adding strength but it sure does come at a high price for a street car, if it's for a race only car, go for it. Quote Link to comment Share on other sites More sharing options...
biohzrd Posted July 1, 2002 Author Share Posted July 1, 2002 i understand what you're saying about the vibration issue. that would be a down side to doing it. i saw a person one time put a piece of 1/4 inch rubber in between the frame and the plate to combat this. as his was connected using a piece of angle iron welded to the plate on each side and then bolted to the frame. i doudt that it would have fixed the problem totally but i'm sure it helped. as for the car it will mainly be a weekend car for going to the local hangouts and the track. not to much actual "driving" is planned for it. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 1, 2002 Share Posted July 1, 2002 As you say, it could be made to transmit the vibration though a small stud type engine mount (looks like a big rubber marshmellow with a stud that runs through it, some street rods run this sort of thing) and you could actually probably connect them to the Datsuns crossmember engine mount pier's on each side as Terry Oxandale did. I'd have to wonder why if its a Chevy, theres JTR and MSA kits, but if its a cost factor, plates would probably be slightly cheaper for sure, although with the additional mods I'm not sure thats necessarily the case. It depends on where the plates connect to the motor too. If it uses the water pump as part of its mount bolts, then it would put the waterpump out the thickness of your motor plate and all the accessory drive would have to be equally shimmed out. If your not using the three bolts that are on the front of the heads for anything, they could be used to, but I'd make sure to use some good grade of bolt. If your carbing you MAY be able to use a mech fuel pump since its on the block and not the front timing cover on a Chevy. Those are a few issues I see right off the top, otherwise, I can't see to many other problems. It might give you a bit more latitude in positioning as well. Good luck with your project. Regards, Lone Quote Link to comment Share on other sites More sharing options...
biohzrd Posted July 1, 2002 Author Share Posted July 1, 2002 i should give you a little background on the combo i'll be using for the project and the reason i'm wanting to use the plates. the motor is going to be a 383 stroker with 588 hp and 506 ft tq. this of course is befor any spray that i may end up using at a later date. i'm looking for as rigid and stable of a mount as possible. this last weekend i bent the frame on my camaro with a less radicle engine then whats going to go in the z. i fully intend on putting in a cage, strut braces, ect....ect.... i'll give up a little comfort for peice of mind that i'm not going to tweak anything. i'm also not looking at going in a streight line all the time either. we finally got a true auot+ track here and want to persue that aswell. unfortunatly i still want the car to be as streetable as possible with a/c and a full interior. i know it's going to be a pain but it's one i want to persue. i guess have my cake and eat it too. i also thought about the mods to my belt setup aswell. i think i should be able to either have a water pump machined down or as you stated just use shims. i'll be using an electrical fuel pump and will be blocking off the mount for that. maybe terry can read this and give me some hints Quote Link to comment Share on other sites More sharing options...
Guest 1fastz Posted July 2, 2002 Share Posted July 2, 2002 i runt he jtr kits and i can tell you its plenty stiff.. i have a 700 rear wheel horse z and i have not had any problems with that setup .. i run 9.70s at 143 mph so if it can handle that im sure its sttrong enough for your use. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 2, 2002 Share Posted July 2, 2002 The main reason I used the plates was to stiffen the chassis. A 289 is not a torque monster, but in road racing the chassis does wierd things. I wanted the engine and tranny to be the back-bone of the chassis. With the front and rear plates and the tranny solidly mounted (multiple bolt spacing at each connection), it stiffens against any pitching movement. The plates also help any twisting of the frame rails as they extend out from the firewall. I even tied the strut towers bracing to the block too. Technically it's not considered a "stressed member", but it comes real close. Before I did this, the door gap would change whenever I jacked the car up on the jack tubes (on both sides simultaneously) which split the wheel base in half. Now there is absolutely no deviation from when it's sitting on the ground. I was concerned about what the stresses where doing to the block and aluminum tranny case, but after 10 years I've not seen any problems with that aspect. Quote Link to comment Share on other sites More sharing options...
biohzrd Posted July 2, 2002 Author Share Posted July 2, 2002 thanks for the info. i understand that the jtr mounts are strong enough don't get me wrong, but like terry said i'm wanting to tie the entire car together and make it act as one unit. this was the main reason i was wanting to go with the plate setup. it just seems like the best setup for me. terry if you don't mind telling me where did you connect the front and rear plates at, and is vibration that appearent. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted July 2, 2002 Share Posted July 2, 2002 Aw, silly me , I always forget the obvious, yeah milling would be a good way out. Sounds like a great plan, should be a awesome car, hope the cage helps stiffen it, if that sort of HP bent your camaro, holy cow, I'd hate to see what it'd do to a Datsun chassis. Anyway, good luck with it. Regards, Lone Quote Link to comment Share on other sites More sharing options...
jap tin Posted July 4, 2002 Share Posted July 4, 2002 700 rwhp and 143 is a 3100 pound Z car. Damm, thats a porker. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 4, 2002 Share Posted July 4, 2002 Bio; the rear plate is attached about 3/4" forward of the firewall, and the other plate is attached to the (on my first design) engine mount pedestals that L24 bolted to. I double bolt all the mounting locations with two bolts spaced about 3" apart at each of the 4 connections (on both plates) to prevent any twisting of the plate/frame joint. With only one bolt at each location, there would be nothing preventing the two from rotating relative to each other, and hence, ineffective in stiffening the chassis. The block then keeps the rails parallel. Then with the tranny down solid, the rails are prevented from flexing up and down relative to the rest of the body. With a balanced engine (especially the SBC) the vibrations are not bad, but that is a very subjective opinion that I'm sure is not shared by others wanting a more domesticated ride. Quote Link to comment Share on other sites More sharing options...
blueovalz Posted July 4, 2002 Share Posted July 4, 2002 Bio; the rear plate is attached about 3/4" forward of the firewall, and the other plate is attached to the (on my first design) engine mount pedestals that L24 bolted to. I double bolt all the mounting locations with two bolts spaced about 3" apart at each of the 4 connections (on both plates) to prevent any twisting of the plate/frame joint. With only one bolt at each location, there would be nothing preventing the two from rotating relative to each other, and hence, ineffective in stiffening the chassis. The block then keeps the rails parallel. Then with the tranny down solid, the rails are prevented from flexing up and down relative to the rest of the body. With a balanced engine (especially the SBC) the vibrations are not bad, but that is a very subjective opinion that I'm sure is not shared by others wanting a more domesticated ride. Here's the picture of the plates only on the frame. Quote Link to comment Share on other sites More sharing options...
biohzrd Posted July 5, 2002 Author Share Posted July 5, 2002 thanks alot for the pics. that really helps being able to see it. by the way. thanks for all the photo documenting. i know it's a big help for me aswell as others. Quote Link to comment Share on other sites More sharing options...
HS1370 Posted July 5, 2002 Share Posted July 5, 2002 I have thought about using plates for the 4.3 that I will be putting into my Z. My thought had been to use urethane bushings to isolate the plate/chassis. It wouldn't be as stiff as solid mounting but it should isolate the vibrations. Quote Link to comment Share on other sites More sharing options...
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