Off topic engine question

[AutoInsane]

I know the question is off topic so please accept my apologies. I promise I wont make a habit of this.

I was on a Jeep forum and a fellow was asking questions about building a Ford (waits a sec..looks up.....ok..no lightening ...keep typing) 302 to put into a Jeep. He was thinking about putting GT 40 heads on it. He was told the GT-40 heads were only good for hi end power and also the 302 in general isnt as good for low end torque as the Chevy (did i redeem myself mentioning Chevy?) 350.

Wouldnt you be able to build any engine to be good in either the low end torque range or to be a high end, high horse power engine?

Isnt the cam the true deciding factor and the valve train in general of low end or high end. I do understand the intake manifold also plays a part in range of power.

What would make a design of a cylinder head specific to high end or low end power?

One again sorry for the obsecure question but it is bugging me and I know that I will get a good answer here.

[Chevy454]

Head design is a pretty big factor in determining the power band. An example would be the different heads used on the big block Chevy. Big, square port heads are more for top end, where small, round port heads are for low end. I think it has to do with volume?

[JoeC]

Cyl head port volume and valve size will change your power curve. If you ever see BB Chevy truck heads - the valves look like nails compared to valves in the square port heads.

[PxTx]

Don't over look stoke. Longer stroke engines will make more low end torque when compared to a short stroke engine of equal displacement.

[Stefano]

JoeC,
Some have said the truck head valves look peanut sized compared to the HI-PO BB valves.

[Stefano]

How about a Shelby American built FE. They run fine fuel injected. http://www.yenko.net/ubb/smilies/images/icons/smile.gif

[PxTx]

Top end, meaning high MPH is a result of horsepower, not torque. I believe you are looking for and engine with low end grunt. Specifically and injected one, so I am thinking you must have a rock-climber that will frequently slosh the fuel bowl of a carburetor.

A 350 TPI engine will give you a good amount of torque (due to its long intake runner), but those motors are so sexy and desirable that their cost can be the most unattractive part.

I may be a little biased answering on this board, but I think it would be best to go with a big block for torque. If you have no religion in terms of mixing engine manufacturer with body type (and it sounds as if you don't) run an old Buick 455 or better yet a 472 or 500 Caddy!

A simple TBI injection will allow you to use a stock donor mill.

I hope someone here is willing to back me up. Can anyone else testify to these torque monster?

[DarkoStoj]

I'm the guy he is talking about that is planning a V8 swap for my Jeep. I was contemplating wheter I would swap in a Ford 302 out of a Stang or some kind of TPI 350. Whatever I swap in would need to be fuel injected. The fact that the 302 is more of a horsepower motor, rather than top end motor, I am considering a TPI 350. Is there a specific engine I should look for performance wise? Or is there any additional information

[TC]

Personally,I'm not a big fan of electronic fuel injections...for several reasons.
The biggest being,there expensive to work on,difficult to diagnose,and require a lot of expensive/specialised tools,if you plan to work on it your self.
Plus,your more limited to what you can do,if you want to make some more horse power...unless price is no concern.
Also,*in my opinion*...I don't think they offer all that much over a carburetored engine,in most cases...other than turbo applications.

It's a pretty tuff question to answer,without knowing what the motor needs to do,what the budget is(if there is one),and what gears/trans/weight of vehicle is...ect.

But,if the most bang for the bucks the plan,I would defiantly go with the 350 sb.There generally easy to find parts for,and prolly the most economical engine to play with.If fuel injection is an absolute must,a TBI might be an option too.

[DarkoStoj]

for street cars a carb would do a fine job, but street cars don't get on angles of 70*. When the Jeep hits the high inclines the floats in the carb don't supply fuel to the engine, leaving you stranded in a very dangerous spot, maybe even a rollover. If I swap in a V8, It must be fuel injected. I would like to swap in a big block, but it would be too much weight, and If I were to swap in something bigger than a SB 350, I would like to swap in a caddy 500, I've heard good things about those motors. Does anyone know how much a average TPI 350 makes power/torque wise?

[TC]

Yeah,that defiantly sounds like it would be an unpleasant situation.
The mid 90's Vortec 350's used in pick ups,were 225hp/330torque...and would prolly work quite well,also should be fairly easy to find....and might be reasonably priced too.
The late 90's Firehawk,and Camaro SS LS1 motors would be better yet 320hp/345torque,but prolly much harder to come by...and might be kind of pricy.
Also the 93-97 LT1 was 275-285hp,and would be a good motor too...prolly hard to find though.

[PxTx]

If you are serious about rock climbing and stuff with the Jeep, don't mess with a small block. the 500 Caddy is your best bet. It makes beaucoup torque just off idle. A small block (especially newer, non TPI injected ones) will not make any torque until 2,800 rpm. Their real torque won't come in until about 3,800 rpm.

If you need to move your Jeep, you'll want to do it off idle. Those caddy mills make 550 ft lbs of torque. With 400 ft. pound at 1,500 rpm. Using torque at higher RPM will cause you to overheat the torque converter or clutch, because of the way the Jeep must be driven.

The caddy mill is not that heavy at all with an aluminum intake and headers.

I swung a 472 Caddy in a 78 Pontiac Le Mans. It had the Black GN theme and I used GTO 7.7 Litre emblems I custom made. Other than looks, the car was stock- suspension and all. The front end was lowered about 1" and the car handled very well (would have benefitted from headers and an aluminum intake). I would do it again. The 472 was from a 1973 vintage car and was bone stock with 209,000 miles. Would you believe it ran 13.4 in the quarter? Would you believe that was on street tires with a 2.14:1 gear in an open end 7.5 rear!

Go with the caddy- they can be found for cheap and no matter how old they are, they won't smoke. Drop it in and go!

[DarkoStoj]

I just found a orgional Jeep AMC 401 motor. These are probably the most sought after Jeep motors becuase they have the exact same block as the 304, 390, and 360. It will also bolt right in. stock it makes 215hp/320lb/ft. They guy wants $400, and I could go around and sell it for $800 if I wanted too, but that caddy engine sounds really nice. What did the caddy 500 come from, and what is a good car to look for that they came in? Is it possible to swap a fuel injection on it? with that much torque, I would also need to change axles.. well basically my whole drivetrain. Does anyone know how much the Caddy 500 weighs? Torque and power is mostly used for the sand dunes, and mud pits. A 4 banger does a good job on the rocks, but it would be nice to be able to do wheelies with that much power. Also, I would like to avoid any Chevy 350 newer than the L98. This jeep will go through numerous water crossings, and I'd like to stay away from the optispark in the LT1. Once again thanks a lot for the help.