what are the differences when you build a motor for torque, versus when you build a motor for horsepower and top-end??? i'm considering trying to build a 300-6 (which already has a ton of torque), to get even more torque outta it?? how would i accomplish this?? i plan to run a zf 5 spd transmission behind it, and the truck will be 4x4...i'm also debating on what gear ratio i want to run in my front and rear axles...either 3.73's or 4.10's...which would be better?

MontanaFord

 

I once explored building up a 300, I decided to keep the truck and get another one with a 351w best decision I made. What you will find out, if you throw the same amount of money at a v-8 as you do the inline 6, the v-8 will make a ton more hp and tq. One reason, a 302-351 will almost make as much hp and tq stock (depending on application) than a modified six. If your looking to do it for the novelty of having something different, well I think thats great, I think a modified six is great from the "its a little something different" aspect.

Building for torque you want a lot of cubes pulling air through a smaller head port that has great velocity. For high end hp, you may still want a lot of cubes or alternatively less cubic inches and more rpm, breathing through larger intake ports. For high end hp you may want larger ports on the heads but they still must be effective, so there are limitation to how big. Someone make the comment one time, in a drag racing sceneario (high end hp is the goal) the engine that is making the most hp or flowing the most cfm through the heads with the smallest ports will win everytime. Their definition of small is still too large for something that wants to solely generate torque, unless of course it a stroked big block.

You are limited to the stock cylinder heads, the only aftermarket head available for the six has no water passages, so it wouldn't do very well in a street application, efi heads are fine but a carbed head is a little better, either with some work will do fine. YOu could also use an inline six 240 head, it would bump your compression ratio drastically on the 300 but premium fuel would be required. You can stroke that sucker, the crank runs last time I checked $1000, IMO why spend that on a six and get 330 cubes when you can purchase a 351w long block for simillar money, and have 21 more cubic inches and a lot more potential.

You could make a long rod set up using the inline six 240 rods with keith black 351w stroker pistons, that would give you a little more hp and tq.

If you have a carbed engine, going with an aftermaket intake, 500cfm carb and a cam and headers (or efi exhaust manifolds-they are almost as good as headers if not equivalent in design and a whole lot cheaper), you should expect 205 +/- hp with 280 +/- ftlbstq and if properly tuned decent mpg, some mild port work on the heads would help as well. If you have an efi setup, your limited to the stock intake, you can upgrade the injectors easily, might wanna add an adjustable fuel psi regulator to fine tune it, you can find cams and headers (but I would stick with the efi manifolds on it) the down side you need a chip or a chassis dyno to get the information needed to set up the program, so the engine performs as desired, in short a lot more money than I would care to spend.

You can go to any autoparts store and pick up a longblock 302/351 for $1000-1200 plus another 200 for the core if you don't have one or look around there are modified 302's for sale everywhere seems like.

Don't take my post as telling you what you should do, again from the being a little different aspect, I think a modified six is great, I couldn't justify the hp gains per dollar invested in the project.

cliffordperformance.com has anything you could want for the six cylinder, probably be better off calling them IMO.

Any cam company offers a camshaft for the six.
<!fordsix.com is a webiste that talks nothing but inline ford sixes, one fella has a 300 drag car that is impressive.>

If your looking for street use of the vehicle IMO I would go with the 3.73's if its mainly a toy for mudding then 4.10's.

Good luck

 

We have a good 300-6 forum here https://www.ford-trucks.com/forums/f...splay.php?f=52 that has lots of information.

 

look up the specs for a 1971 or earlier 240/300 get a 71 timing chain set, a good small-tube header, a good intake and fuel system. get a set of crane roller rockers, and a healthy ignition system.

the early T/C set and roller fulcrums will make the biggest difference in torque.

 

In general. For a high torque engine, you of course want a cam rated in the powerband you are shooting for. In most cases, the ultimate torque gainer is to stroke the engine. You would use Stock weight rods and pistons, as opposed to ultralite. You would aslo use heads that have a high port velocity at lower rpm, no wild port jobs. Even though most people despise them, I have had great luck out of the Chevy type tri-Y headder on v blocks for street application.