What difference there is with left motor mount when going LM318 LM360

Scott...Were did you find a 36

Scott...Were did you find a 360 marine Mag?

"94 dodge w2500 pick up, it is

"94 dodge w2500 pick up, it is a roller engine, I had a custom cam ground "LM360 250hp spec", had to fab a fuel pump drive off the cam and use old lm timing cover. it has more power then I need but runs 100% and much better on fuel. If I stay out of it LOL. It was also cheaper to build then the older engines"

So you put a lobe on the cam a

So you put a lobe on the cam and the LA timing cover bolts right up to mount the fuel pump? Do you have a double roller chain too?

"No, the fuel pump lobe is a b

"No, the fuel pump lobe is a bolt on unit, I had a 1/2" stub machined and bolted both to front of the camshaft, and used the stock timing cover with the boss to bolt on the fuel pump."

"Where are the differences on

"Where are the differences on the later 360 magnum versus LM360?
The head, intake, maybe cams, higher rpm?
As LM360 is ~275hp and magnum 330hp that difference could come easily with better head and intake.
(e.g. getting rather mild degree cam with more lift increases the flow -> more hp)

Is the block similar between magnum and A series?"

"...."Where are the differ

"...."Where are the differences on the later 360 magnum versus LM360? The head, intake, maybe cams, higher rpm?"

Yup, yup and yup! Believe it or not, the PORTS of a M360 marine engine are the same size as the original 273 cube Mopar small block--they're puny and restrictive. That makes for great torque which cruiser dudes like me appreciate. Frankly, simply bolting on a set of automotive 340/ 360 heads would do wonders for horsepower (at the expense of low speed torque).

Personally, I have no use for top end hp and rarely open the secondary barrels since my boat planes easily one the primaries.

So......There's a ton of hp potential hiding in there if you're looking to haul butt.

Jeff"

"Actually you can put the new

"Actually you can put the new Magnum heads on a older LA/LM block I personally haven't done it but a freind of mine has done a few. The heads flow a ton more than the stock LM 318/360 heads.
And the Exhaust ports are the same as the early heads I have been told, so it would be easy upgrade. I've been thinking of finishing up a M360 I have here for a project boat were building and using the Magnum heads, and were looking into trying to do a EFI setup also.

But I know a lot of guys who have built engines and used the smaller port 318 heads just for the reason Jeff mentioned, they wanted torque not the high end HP. In MOST boats we would be using the torque more than all out HP.

Dave"

"Maybe the heads are somewhat

"Maybe the heads are somewhat easily interchangeable, thus there might be some other actions that must be taken. As you mentioned the EFI, etc. stuff, that the newer car engines do have (instead the bit outdated, but reliable, carbs that are used in these older A type small blocks).

The torque levels between these different blocks and heads is a bit hidden area. What I mean is that there is a lot of talk about the max HP, not about the torque level and it's variation with different rpm levels.
As all may probably agree, the torque is the most wanted goal, when e.g. thinking the engine which is used in a boat. (certainly there are some exceptions, where the e.g. race situations you might pull at full throttle, but...)

This actually points to be a bit similar case as with cars, as with a engine that has a good torque you can drive much better in different situations (not talking about race engines).

In some magazine there was a following list (maybe from -69):
Dodge-Plymouth small V8
Type 190/273
Hp@rpm 190@4400
Torque@rpm 260@2000
Compr. 9.0:1
Carb. 2-bbl

Type 230/318
Hp@rpm 230@4400
Torque@rpm 340@2000
Compr. 9.2:1
Carb. 2-bbl

Type 275/340
Hp@rpm 230@4400
Torque@rpm 340@3200
Compr. 10.5:1
Carb. 4-bbl

As looking that list, the 340 seems to have more hp, but the max torque comes later than with the 273 or 318.

So, how to raise the torque with the LM 318/340/360 based engines?

Usually changing the cams into more duration, makes a weaker low end which is not my intention now.
When keeping the duration small but raising the cam lift the flow raises. If also changing into more flowing head and headers, the engine comes more efficient in torque wise but probably does not raise so much the max hp.

I do have some experience from 2-liter & 4 cylinder engines where this is a valid scenario but not from V8 area.

How to reach the max torque at 2000 rpm and keep it to higher rpms with LM360 (e.g. high & steady torque from 2000 to 4000) would be interesting point to discuss."

"Type 275/340
[url=""]Hp@rpm

"Type 275/340
Hp@rpm 230@4400
Torque@rpm 340@3200
Compr. 10.5:1
Carb. 4-bbl

Note that, unlike the other motors, the hp was measured as "230 @ 4400" when it's colser to 300 @ 5,000 on that old hot rod mill. I suspect the Feds or insurance companies had something to do with that!

On exhaust port sizes, the marine exhaust MANIFOLDS have large enough ports for street heads, even though the marine heads they attach to have MUCH smaller ports.

Jeff"