Alm. Blocks
 

For you experienced engine guys out there ... What would be the pro's and con's of using a all aluminun motor in fresh water. Except for the price. Would they have as much durrability as iron blocks in a N/A 598 or 632. Would the weight saveings be notable in a twin 40 ft V

This came up awhile back, the general consensus was that if it was a good idea, all of the major engine builders would be doing it and they don't. BUT it was also mentioned that Raylar recently introduced and aluminum block motor, something worth taking into consideration. Talk to mrhorsepower(Dean Gellner), he built some aluminum block motors for a flat deck I was looking at, but we passed on the boat so I didn't want to waste his time talking to him about the motors.

i think it depends more on the weight balance of the boat and the rigging. when i win the powerball i am going to build something with aluminum block power and closed loop fresh water cooling. either a 800ci bbc single engine 28-30 ft or a twin staggered big small blocks...

i pipe dream a lot....

aluminum blocks rot easily.Another draw back is idle quality when first started cold due to valve lash under the expansion rate.

depends more on the weight balance of the boat and the rigging ..... what country are they doing this in ????? :party-smiley-004:

And where you choose to put your cooler also plays a huge roll. :drink: MR

would a block heater help solve that problem?

Yes if you could install one.

Didn't High Torque Marine have an Aluminum Block and after some problems, Sterling Performance Engines was working with them.

alm. motors
 

Seems like the idling issue would be erelevent . How long does it take to warm a moter two or three times a day at 80 or 90 degree outside temp ?Not like we run these things in snow and ice! Everyone worryies about top end speed with little fuel skinny wife or girlfriend no gear no cooler to get 1 or 2 mph. Seems like all alm motor at half the weight would save like 600- 700 pounds on a twin eng application right on the tail end compared to all stock iron stuff . Getting the tail end up is all the talk on props and hull design. ANY THOUGHTS ?

Isn't the Ilmor V10 all aluminum and they have been having good results with it even in salt.

Stick with Iron. THe corrosion factor isn't worth worrying about.

Stick with 598 also. You will make just as much power as the 632, and it will last longer.

Good luck.

Im building two LS7 all aluminim small blocks for my 30 skater go closed cooling and dont woory about corrosion i had to keep the weight down so thats why we went this way they are 460 cubic inch 700 hp all day long efi naturaly aspirated cant beat it should be interesting

My Experience
 

My Ilmor 710 is all aluminum and fresh water (closed loop) cooled.

In fresh water there is little to no downside using an open loop aluminum block. Salt should be closed loop.

They are as, or more durable than iron. Unlike an iron block they can also be repaired when you kick a rod out of the side. This is why there is such a robust aftermarket for them - if you take care of it it can last a lifetime. The aluminum "expansion issue" was solved decades ago by companies like Donovan, Rodeck, GM etc.

(Donovan can let you REALLY build a big engine) Steve Schmidt builds these a lot.

Most prestigious builders DO offer an aluminum option for a substantial extra premium of 2-5K a block. It's not always on the parts sheet but a quick phone call will get you an already memorized uplift quote.

The weight savings are are at bout 200LB over standard big block. On a twin engine boat or a 21ft river runner this is a big difference.

The downside comes when you

1. Have to bold accessories TO it that require more than a few lb/ft of torque- you cant just let a a line mechanic jab around it- you need to be really careful hell pull the threads out- you pretty much need to helicoil all heavy torque threads.

2. Cut the check.



Uncle Dave

Laveycraft 2750 -710
Laveycraft 20.8 Sebring

The aluminum between the cylinders is very thin because of the sleeves. You have to check how deep the head bolt holes there are threaded and get head studs that are longer than normal to thread into them. If you use regular studs, you'll pull the aluminum right out from between the sleeves.

The weight savings is at most 150lbs. An iron Merlin block is 260lbs and a Chevy block is lighter than that. Using aluminum heads saves about 45lbs ea. Times two for a twin engine boat you save 4-500lbs. In a smaller twin engine boat like a 30' Scarab or a 27' Magnum it would really make a difference. In my Black Thunder, not so much.