1974 Plymouth Roadrunner

MilesnMiles · Post by **MilesnMiles** » Fri Mar 15, 13 9:06 am

Pete, yer right, drivers side engine mount does need some modification. My 360 came with its own mounts and they bolted straight up with one spacer (homemade) being required.
I'm getting old and forgetting stuff

Dave81 · Post by **Dave81** » Fri Mar 15, 13 1:08 pm

MilesnMiles wrote:Pete, yer right, drivers side engine mount does need some modification. My 360 came with its own mounts and they bolted straight up with one spacer (homemade) being required.
I'm getting old and forgetting stuff

Most of the forums i've read reccomend Schumacer (Spelling) engine mounts.

DaveBishop · Post by **DaveBishop** » Fri Mar 15, 13 1:18 pm

Dave81 wrote

Most of the forums i've read reccomend Schumacer (Spelling) engine mounts.

That's only if you are going from small block to big block in an A body

Dave81 · Post by **Dave81** » Fri Mar 15, 13 1:23 pm

DaveBishop wrote:Dave81 wrote
Most of the forums i've read reccomend Schumacer (Spelling) engine mounts.
That's only if you are going from small block to big block in an A body

Never did understand how basically the same engine had different mounts...........
But i have definately read on 318 upgrade threads on FABO that the 360 requires shimming or something to get it to fit. Pretty sure i havent dreamt it?

Or........is this a A bod only issue (k member differences?)

Not sure?

Pete · Post by **Pete** » Fri Mar 15, 13 1:28 pm

The Block is different.......

DaveBishop · Post by **DaveBishop** » Fri Mar 15, 13 1:29 pm

The 318 left side engine mount is different on the 340/360 in the past I have just shimmed them but Realsteel sell the correct ones I have just got some off them

Dave81 · Post by **Dave81** » Fri Mar 15, 13 1:41 pm

Pete wrote:The Block is different.......

I'm talking external dimensions Pete, not Bore and Stroke etc............Or do i need to resign from the club in shame.............

My ref: http://www.allpar.com/mopar/4bbl.html

Pete · Post by **Pete** » Fri Mar 15, 13 2:06 pm

Block Lug.............

Carl · Post by **Carl** » Fri Mar 15, 13 3:23 pm

Dave wrote:
Carl wrote:The great 340 360 debate short strike bigger bore more HP. Smaller bore, longer stroke more torque.
You seem to be totally mistaken about how an engine makes power and what torque and Horsepower are.

Torque is the power an engine makes. Period.

Horsepower is just a way of describing torque in relation to RPM.

The camshaft dictates at what RPM you make torque. NOT the stroke of the engine.

If you make torque at high RPM is is more usable for speed if you have gears. Make torque at low rpm and you need fewer gears but top speed is limited.

Traditionally a low rpm designed engine would be given a long stroke in order to give the piston a higher speed and increase the vacuum signal to the carb.

A high rpm engine already has the high piston speed and so you use a short stroke so that the piston speed is not excessive.

Stroker engines play off higher piston speeds against the gains of having a greater capacity (more air/fuel = more power) but actually work better with single plane intakes and big carbs.

Here endith the lesson.

On the contrary Dave mate, I have a good understanding of how Engines make power and what Torque and Horse power are. I was just stating the age old argument about the 2 Engines

Horsepower is just a way of describing torque in relation to RPM.

I've always known it as......Torque is the power and the HP is how power is measured in time over a distance. i.e. More revs more HP as the revolutions (distance) increase (per minute) the more HP is being produced.

But there is a trade off of the 2 at 5,252 RPM where the Torque and HP are equal, below that figure the Engine produces more Torque less HP, above the figure more HP and the Torque trails off. Hence F1 cars rev to over 18000 RPM.

Cars with lots of bottom end Torque and low HP are quick off the mark but no top end. (Diesels, low maximum rev limit so dont make the HP and are slow compared to a higher revving petrol car of the same cc. Ok gearing helps too.)

A low Torque car with high HP will be sluggish until the revs pick up and away it goes.

But as you say there are other factors to consider as you mentioned

The camshaft dictates at what RPM you make torque. NOT the stroke of the engine.

Yes I know this too. Its the timing of the cam. An earlier closing inlet valve increases bottom end Torque, and a later closing inlet valve can give better top end Torque.

Jon Connolly · Post by **Jon Connolly** » Fri Mar 15, 13 3:38 pm

I have seen 3 different types of smallblock motor mount. There is no need to buy expensive aftermarket mounts .. A combination of one of the available mounts together with washers is all you need

Dave-R · Post by **Dave-R** » Fri Mar 15, 13 3:54 pm

Carl wrote:On the contrary Dave mate, I have a good understanding of how Engines make power and what Torque and Horse power are. I was just stating the age old argument about the 2 Engines

My point was:
It is not the stroke that makes one engine a low rpm torque machine and the other a high rpm high HP machine. Which is what you suggested by that statement.

But there is a trade off of the 2 at 5,252 RPM where the Torque and HP are equal, below that figure the Engine produces more Torque less HP, above the figure more HP and the Torque trails off. Hence F1 cars rev to over 18000 RPM.

But that only happens by virtue of the calulation and how much work James Watt thought a horse could do. (lifting a 550lb weight one foot in one second?) HP is not "real". You cannot measure it directly. It is just a figure.

Yes a F1 engine revs to 18000rpm. And they have increadibly short strokes. But the short stroke is to stop the piston from traveling at supersonic speeds and reduces the parasitic losses due to friction as the piston only has to travel a small distance per revolution and at a slower pace.

Pete · Post by **Pete** » Fri Mar 15, 13 4:01 pm

And they have to come to a virtual stop - although it is more of a figure of Eight.

It is still a lot of metal chunking around -

As I remind myself with 900g 1 litre pistons doing 7200 rpm

Carl · Post by **Carl** » Fri Mar 15, 13 4:06 pm

This statement? "The great 340 360 debate short strike bigger bore more HP. Smaller bore, longer stroke more torque. "

See where you coming from Dave but wasnt actually my words I was just relaying an argument I once read.

hjworton · Post by **hjworton** » Fri Mar 15, 13 8:03 pm

My original thought with the RR was just to run it as-is and trade up when I could afford it to something else....the trouble is I now feel compelled to both bring her back to a far better condition and also....well, I don't think she'd be for sale at any price - I've made a connection. That may change in time but this is now my ride....and with that in mind, a little more shove but not at the cost of reliability or drivability, is what I'm after.

Carl · Post by **Carl** » Fri Mar 15, 13 8:59 pm

In that case Howard just give the 318 a little tweek that will be your cheapest option.