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View Full Version : MCX motor. Is it similiar to chevys LS1 motor?


dreamy_x15
04-26-2007, 10:18 AM
MCX motor looks alot like an chevy LS1 motor. Was just curious if they are similiar. The intake manifold is the reason i am thinking they might be same but of course a marine application. Thanks Josh

MYMC
04-26-2007, 11:03 AM
NO, the LS1 is an aluminum reversed cooled small block. The MCX is a Vortec truck engine (cast iron) using standard cooling with an intake manifold that is supplied by Indmar.

trickskier
04-26-2007, 11:30 AM
NO, the LS1 is an aluminum reversed cooled small block. The MCX is a Vortec truck engine (cast iron) using standard cooling with an intake manifold that is supplied by Indmar.
What does reversed cooled mean?

Diesel
04-26-2007, 11:52 AM
What does reversed cooled mean?

Heads are cooled first.

trickskier
04-26-2007, 11:56 AM
Heads are cooled first.
Thanks Diesel

Prostar Rich
04-26-2007, 11:57 AM
The LS1 engine is not reversed cooled. The LT1 had the reverse cooling.


In 1997 GM introduced a new 5.7-liter LS1 Small-Block for the New 5th Generation Corvette. The LS1 block is all aluminum block. The new block weighed 107lbs. compared to the previous small block LT1 which weighed 160lbs. The LS series block also features a six bolt main which also for less crank walk and can handle more power than the LT1/4 blocks. The LS1 block also eliminated the reverse cooling that the LT1’s had. The reason LT1 reversed cooled the motor was to make more power, by increasing the compression. But the LT1 cooling method was nothing more than a fix that allowed the limited cooling of the old Small-block head to work with the higher compression necessary to reach the 300 horsepower level. The problem with reverse cooling caused air bubbles flowing upward and coolant flowing downward. Air in the cooling system causes problems around the combustion chamber, which causes localized boiling and that, in turn, allows hot spots to develop on chamber walls which cause detonation. It was difficult to keep air out of the GEN II cooling system. The LS1 featured a brand new composite intake, which weighed less, and ran cooler.

The LS1 featured a whole new ignition system which resolved the problems that the LT1 optispark presented, or as many call it the optic-CRAP. The new ignition system featured a coil per cylinder ignition design. The coils were mounted to on top of the valve cover. This enables less spark energy by shorter spark plug wires increasing efficiency by 100%. The shorter plug wires reduce “noise” otherwise known as electronic interference caused by on-board computers and sound systems.

The LS1 also features new pistons which are also lighter than the LT1/4. Improvements in LS1 rods and pistons have reduced the weight of each rod/piston assembly by 120 grams compared to the same LT4 pieces. That significant decrease in weight guarantees the engine will rev quicker and be more durable at high engine speeds. Along with the other improvements over the LT1, the LS1 had a redesigned cylinder head which feature and valve angel of 15 degrees.

All the advancements in the 3rd generation Small-Block lead to a motor which produce the highest horsepower levels that a pushrod motor has ever seen. Along with the power increases the LS1/LS6 is the most fuel efficient system to date.

HTH,
Prostar Rich

MYMC
04-26-2007, 12:46 PM
The LS1 engine is not reversed cooled. The LT1 had the reverse cooling.
I stand corrected


In 1997 GM introduced a new 5.7-liter LS1 Small-Block for the New 5th Generation Corvette. The LS1 block is all aluminum block. The new block weighed 107lbs. compared to the previous small block LT1 which weighed 160lbs. The LS series block also features a six bolt main which also for less crank walk and can handle more power than the LT1/4 blocks. The LS1 block also eliminated the reverse cooling that the LT1’s had. The reason LT1 reversed cooled the motor was to make more power, by increasing the compression. But the LT1 cooling method was nothing more than a fix that allowed the limited cooling of the old Small-block head to work with the higher compression necessary to reach the 300 horsepower level. The problem with reverse cooling caused air bubbles flowing upward and coolant flowing downward. Air in the cooling system causes problems around the combustion chamber, which causes localized boiling and that, in turn, allows hot spots to develop on chamber walls which cause detonation. It was difficult to keep air out of the GEN II cooling system. The LS1 featured a brand new composite intake, which weighed less, and ran cooler.
Not exactley true...reverse cooling didn't cause the issues with air being trapped, engine placement did. Many people did not take the time or effort to bleed the system properly. After building and rebuilding over 300 Winston Cup, Busch and Super Truck engines with reverse cooling we never had one issue with air bubbles or hot spots. There is not "real" heat in the block it is all in the heads and that is where we benefitted by cooling them first...half of them we built had concrete in the block up to about 1/2 way for weight and there was nothing to cool down by the oil pan.

The LS1 featured a whole new ignition system which resolved the problems that the LT1 optispark presented, or as many call it the optic-CRAP. The new ignition system featured a coil per cylinder ignition design. The coils were mounted to on top of the valve cover. This enables less spark energy by shorter spark plug wires increasing efficiency by 100%. The shorter plug wires reduce “noise” otherwise known as electronic interference caused by on-board computers and sound systems.
LT-1's and LT-4 were big on making you walk.

The LS1 also features new pistons which are also lighter than the LT1/4. Improvements in LS1 rods and pistons have reduced the weight of each rod/piston assembly by 120 grams compared to the same LT4 pieces. That significant decrease in weight guarantees the engine will rev quicker and be more durable at high engine speeds. Along with the other improvements over the LT1, the LS1 had a redesigned cylinder head which feature and valve angel of 15 degrees.
You forgot to mention how the weight loss occured. The rods were powdered metal with "snap cap" technology...nice & cheap. They were junk and so was the crank and pistons.

All the advancements in the 3rd generation Small-Block lead to a motor which produce the highest horsepower levels that a pushrod motor has ever seen. Along with the power increases the LS1/LS6 is the most fuel efficient system to date.
True, plus you got all the piston slap you could stand and then some...no extra charge.

HTH,
Prostar Rich
Thought the HTH stood for "hand to hand":rolleyes:

Diesel
04-26-2007, 01:32 PM
True, plus you got all the piston slap you could stand and then some...no extra charge.



Love to hear you theory on this one. I have heard many different comments and just wanted to see what your thoughts were.

MYMC
04-26-2007, 04:34 PM
Love to hear you theory on this one. I have heard many different comments and just wanted to see what your thoughts were.
Cast pistons, aluminum block w/cast iron liners...differential expansion rates and the required tolerance for that hypertutecitc (read junk) piston. You can run a tighter bore with the stock piston in a cast block, but when you are using a sleeve in an aluminum block with minimal silicone added (I think the block was actually 2% silicone making it hypoeutectic) then you set yourself up for this...particularly when made in mass assembly where hand fitting isnt possible.

BTW, this is taken from the "Like a Knock website:
Around 1998, GM switched from a "Select Build" method of manufacturing and/or assembling engines to a "Net Build" method, in order to save money on manufacturing and/or assembly. In the Select Build process, pistons and cylinders are matched for size and fit. GM's new "Net Build" method of manufacturing and/or assembly, in contrast, assumes all pistons will fit equally well in all cylinders and does not allow for variations in the size of engine cylinders or pistons. The pistons of slightly varying size (all within spec) are not individually matched with the cylinders of slightly varying size (all within spec).

rstitson
04-26-2007, 08:24 PM
I have a 2000 corvette. It can slap/knock, whatever, a bit when cold (not always) when first started up. After that can't notice a thing. I did get GM to give me a 6 year 100,000 mile garauntee on it though. As far a fuel efficient, when driven for mileage it is pretty good. I got ~30 miles/gallon from maine to memphis. Of course I very seldom drive it for fuel efficiency.