Vintage Mustang Forums banner
  • Hey everyone! Enter your ride HERE to be a part of this month's Ride of the Month Challenge!

1 - 2 of 2 Posts

·
Registered
Joined
·
209 Posts
Discussion Starter #1
In the latest M & F mag, there is a story on a 289 rebuild for a tiger. Couple of questions...

1. What do the motor rebuild gurus think of the build for a mile street? Probably still want more?

2. It says the rods were resized and refitted..what does that mean?

3. If I recall, they said the build up cost >$4K...would that be possible in such a mile build? I know, I know, anything is possible. I guess that also includes the centerforce clutch.

4. The max HP comes at a very high RPM level...or so it seems? The motor isn't a screaming stroker...

Anyway, just some questions. I plan to pull my vert's motor after the first of the year. I would have thought the build up they show would be pretty cost effective to mimic.
 

·
Registered
Joined
·
21,337 Posts
Didn't see the article, I don't subscribe but maybe I can answer some of your questions.

Mild street, well, that's a pretty good idea if it's going to be driven on the street. If you look at any type of racing, the cars are built and tuned specifically for each track to get the most out of the car. If you look at the street as your "track" t makes an awful lot of sense to build it that way to maximizes it's output. HP is a function or engine torque times RPM divided by 5252. The faster you can spin the engine, the more hp you can make provided the cam is designd to work in that RPM range. Basically a hotter cam moves the torque peak higher up in RPMs at the expense of taking away torque at lower RPMs. Everybody always wants more. A mild street engine will stomp all over a more radical, higher HP motor of the same size on the street it the more radical engine isn't allowed to run in it's needed RPM range to amake it's power since it's given up it's lower end power. If the street engine make all of it's power from 1K to lets say 5K RPMs and a radical, higher HP engine of the same size, makes it's power above 5K rpm, the mild steet engine is going to make more power then the radical engine on the street.

Resizing means exactly that. If you look at a connecting rod, the big end is split into 2 pieces. Over time and abuse, the big end that fits around the crankshaft can be elongated. The connecting rod looses it's ability to hold the bearing in it's place and to keep the needed, proper clearences. When the rod is resized, they re-machine the 2 mating surface flat again. Since material has been removed, the opening now becomes egg shaped. They hone the big end round again, making it true. Refitted means they put new rod bolts in.

4K, well they may have been using list prices and paying for every little detail. Labor costs are also going to vary in different parts of the country. I guess this is the best I can say on this.

Again, I didn't read the article but like I said before, HP is a function or engine torque multiplied by RPM. The smaller the engine, the faster it needs to spin to make power. An engine is nothing more then an air pump with only so much air being displaced each revolution.
 
1 - 2 of 2 Posts
Top