I have to ask, whats best engine size for towing?

Could, could, could and could, sorry beat you to it Tim

Mario

Ford 302 small-block.

I can't argue with that, it was the v6 that was in the ford rangers untill Budget stopped renting them out, thinking I might have to go back to the new malibu's myself.

Mario

Or a Chevy 350:

thats one nice car

Mario

Stock TIV 1700/1800 or 2000 - pushes a 4k pound bus along ok. Just need to conver it to upright cooling.

Mario,

I'd build it big, with a very mild cam, and using thiiiiick wall cylinders. A stock 69mm crank would work great (keeping costs down) because you wouldn't be revving it high. If money is not an object, then a stroker crank would be on the shopping list. Meaning a couple of steps more work and details, more difficult engine to put together if you haven't done many before. (I would think you have, but I am going through some very basic issues here for the benefit of other readers)

Also keep the valve size relatively small, as well as intake port diameter and carb venturies. Small passages flow more aggressively at lower revs, and this wont be a high rpm screamer. You lose top end ponies but gain low end torque and driveability.

Compression ratio of course is a big factor, and is mostly dependant on the cam.

I guess my choice for this purpose would be something like 78x90.5 with a W110 cam (no bigger) and run 8.5:1 compression ratio with good high octane fuel.

That's a good healthy 2007cc with over 120hp and tonnnns of torque. Will last forever too, and you can let your mother drive it, it would run as smooth and easy as any modern day car. (Assuming the carbs and ignition are built and tuned right).

Plus at this performance level you have the luxury of building a very quiet exhaust system, and you can use boxed (quiet) air cleaners for the carbs too.

Just my opinions of course.

Jan

Hey Jan thanks I'm on stock 1600 engine 4 in the last month and the guys in the military on his way back to Iraq so he says hell have money saved to build a good engine I don't think he will want much more then 1776 I'd like to do a balanced crank and If I do go with a 110 cam, would I want to take Gene Burgs advice and do double valve springs? that in turn would mean stainless valves right?the last 1776 has for a 21 window and I think I could mimic it.

I think I'll take your advice and use stock valve size.

Thanks mario

1776, stock valve size and single heavy duty springs. You'll be good.

Jan

40mm duals work well in daily driver engines up to 2 liters of displacement. Weber IDF or Dellorto DRLA, take your pick. If it has a race cam and it was built to make lots of power in the upper rpm range, like revving it up to 7k= before gear change.. then the 40's are getting small after 1776cc..

Now you are probably talking about a high perf engine, not a tow truck.... :)

you need to design the whole engine from ground up, everything affects everything. One of the first things to decide is what kind of performance and driveability you want from it, i.e. what kind of use it will see? That big of a displacement with a W120 cam wont be happy with stock size valves. It will run, but the valve size will keep it from truly waking up in the upper rpm range, which is where that cam would kick in. Midrange would be ok.

This only as a rule of thumb.

Let me make some assumptions here to try and clear things up... just as an example:

You have a reasonably light car, bug or ghia. You want to go fast. Weight is working in your favor, you can afford to sacrifice low end torque in favor of higher rpm power.

--> you can choose a more aggressive cam. Over 300 degrees duration (advertised) if you wish. Which cam to choose then? If you can afford to build a BIGGER engine, you can choose even a step or two bigger cam. Huge cams dont work all that well in small displacement engines.

Let's assume you took the bigger displacement route. And a big cam.

Now you need bigger valves. Heavier springs, duals most likely. And more head and exhaust flow. Higher compression ratio. Bigger carbs. More fuel flow (electric pump).

--> ok, so now it would rev up and make good power. How did you get more displacement? If just by getting bigger cylinders, then things are looking good. The stiffer valve springs require stiffer push rods. They will be steel, and most likely will be heavier too. Not good. Need to save weight elsewhere in the valvetrain then. Titanium valve retainers, lightweight lifters, rockers... the lighter it is, the better. All that moving weight will a) rob power and hinder revving, and b) vibrate and start trashing places and causing accelerated wear, and increased risk of breakage, valve float....

So you get the valve train lightened and stiffened up. Think it would survive with stock oil pressure, now that there's tons more friction pressure in all the moving parts? ARGH. You also will be putting more sideways load on the cam gear. It will chew up the half-thrust surface of the first cam bearing... so use a double thrust bearing set. and/or straight cut cam gears. (They are noisy, was "quiet" in your list of demands? Sorry...)

If you increased the displacement by fitting a stroker crank in there, and still plan on making the engine rev high.. you really should replace the connecting rods with longer, and stronger ones. (stock rods can be used up to 78mm stroke.. but they no longer are optimal and will once again be a major risk factor and bottleneck for high rpm power.... )

Man, I lost track of where I was going there :) I can't explain this in one newsgroup reply, it is VERY detail critical and there are hundreds of dependencies like these. I'm just going to leave it here, there's no point in going deeper into it.. without a spesific plan for a certain known engine.

Jan

Motor aside, what about the frame (or lack of)?

I've seen tow hitches that bolt to the bumper and run a thin walled tub down under the motor to the tranny mounts. So what kind of tongue weight can that do? Jack shit!

I've seen modified Uhaul type hitches that bolt to the bumper mounts and have a crossbar with the ball mount in the middle. Even if it was a modified class2 hitch, the mount point for the bumpers is still weak. That isn't a frame point, it's the body. The nearest frame point are the shock mounts which is the most rear point where the body bolts to the frame.

Maybe someone, someday will make a real hitch that can handle 300lbs of tongue weight and 3000lbs gross.

I have some ideas how to fab one, and it's on my todo list for my `73.

I'm sure you haven't seen one like I have and its for sale. its a nicely bent

4" pipe that has end plates that mount to the bumper braces on the body. it seems to be something that would hold up real well as a bumper and I don't know what the bug was used to tow but I could ask the past owner, but it being a local car here in central NC bet what ever it towed had an out board engine.

Mario

Maybe it was a pig-roaster. That's the only thing I ever towed with the LCB. You know us stupid rednecks here in NC. We all own pig-roasters, guns, and moonshine stills.

it could have been a pig roaster, tell me shaggie you have never imagined an engine on your pig roaster for any reason functional . lol

Mario

um I might have some that would give your beetle a few extra HP...lol ...stop by shaggie if you need some.

Mario

I just gave away a late model (68 and up) bug tow hitch. Made by Kovil, the number 1 manufacturer out in my part of the world. All solid one piece construction, attaches to the bumper bracket mounting holes and still allows use of stock bumper brackets. I don't think I have any pics, but it was simple enough for me to draw a picture if anyone is interested.

Meets all the strictest safety requirements. Some years back we werent allowed to fab our own hitches, they all had to be factory made and safety approved by the big brother.

Now we can make hitches for older cars without permit. I have made one for a 78 Dodge pickup, I copied a Kovil design from a Chevy. :)

Jan