aluminium heads

[smokediver]

I am in the process of getting an engine together and have the opportunity to get alum. heads at the same price as cast iron . both are the vortec style . I run in salt water . Is there any downfalls to the alum. in the salt . closed cooling isn't an option , raw water only . i don't think there is room for it . I would shave 35 pounds going with the alum. thanks ....

[gcarter]

Woo Hoo...Iron...Aluminum....copper..........
Somethings got to give and it's going to be the heads!!!!:eek!:
Better think about remote mounting a HE.

[need for speed]

come on the wether is good... put that motor in the boat!!!:wink:

[Donziweasel]

I had the same idea, but decided to stay with the cast iron. I am in the process of replacing my non-vortec with vortec. Everyone said to stay with cast iron, although they are heavier and lose weight with a lighter exhaust system. Got mine from Summit racing- Below are the links, I chose the more expensive one because they allow more valve lift for the new cam I am installing.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=NAL%2D12558060&N=700+4294908216+4294924744+4294840140+115&autoview=sku

http://store.summitracing.com/partdetail.asp?autofilter=1&part=SUM%2D151124&N=700+4294908216+4294924744+4294840140+115&autoview=sku

[Cuda]

I guess I'll cross the line and say go aluminum.

A guy that used to work on my boats in St Pete, had aluminum heads on his 36 foot offshore boat, which was raw water cooled. He said he ran those heads for seven years, took them off, and resold them. He ran in nothing but salt water. It's all in the maintainence.

This is the boat I'm talking about. Btw, I have never seen anyone who could handle a boat that size around a dock like he could. :)

[smokediver]

thanks for the advise , here is a tidbit; when using the edelbrock intake , don't use the nice re-useable mercruiser intake gasket , edelbrock has found that there are sealing issues with the aluminium and the gasket , instead , felpro has a gasket that is recomended .

[conyo]

I would say go with a closed cooling system with either iron or aluminum! Salt + any metal other than stainless or titanium is a bad idea. Its only a matter of time before somthing fails. And yes go with the felprp gaskets. I got aluminum intake and heads with the felpros with no problems!

[conyo]

Hey Smokediver one piece of advice on your engine rebuild...

I just went through a full rebuild/repower, I installed a pre-luber oil system to have full oil pressure before starting. Last month we fired it up to break in the new 460. (As you probably know you have to break in a new flat tappet non-roller cam for the first 20 or so minutes, do an oil change and cut open the filter to see particulate content) And also added a bottle of cam break in additive as recommended by my engine builders. Within 6 minutes heard a clacking sound on one side! And misfire through one of the side exhausts. Pulled the valve cover to see if roller rockers were hitting the valve covers. Nope as we suspected... pulled the intake manifold and cam and lifters fried!!!!!!!! Big pain in the ass!!! A word of caution for those rebuilding their motors "do not use flat tappet cam and lifters! invest in a roller cam setup or break in your motor outside the boat. This is really dissapointing to invest all this TIME and money only to have a major failure...in mid summer!!!! Comp cams have been having issues over the last year their only warranty is they'll send you a new cam and lifters...what about the 500 bucks to remove the motor and another 1200 to dryfit and align...again! Not to mention the time I lost. I had full oil pressure before the start and the engine was primed manually and the guys who built my motor are PRO's who have been doing this for 25 odd years. They are nice enough to correct my problem since they recommended the Comp cam. So now I went with a full Crane roller cam setup. Alot more expensive $1100 roller/ $300 flat tappet but the roller is worth it. Just for the reason that there is no cam break in. I know tonnes of engines use non roller cams and can work flawlessly but with the increased number of cam failures lately its not worth the risk.
Just my 2 cent based on a real experiance!

[maddad]

Conyo, it's a shame you had to do your motor twice. You said you had roller rockers on that 460, I assume you mean roller fulcrum vs. sled type. On a 460 ford that usually means BB chevy parts. That combo needs push rods that are .250+/- longer than stock to keep the rocker from hitting the stud. The rocker to stud contact could be what caused the shock that wiped out your cam. Just something to look into, if your curious, especially if you're using the same studs.

[smokediver]

thanks for the advice , i am going with a roller cam .as far as freshwater cooling , it would be a tight fit to say the least ! Once this is all done i think i am going to be in the market for a little bit bigger boat !

[Rootsy]

Hey Smokediver one piece of advice on your engine rebuild...
I just went through a full rebuild/repower, I installed a pre-luber oil system to have full oil pressure before starting. Last month we fired it up to break in the new 460. (As you probably know you have to break in a new flat tappet non-roller cam for the first 20 or so minutes, do an oil change and cut open the filter to see particulate content) And also added a bottle of cam break in additive as recommended by my engine builders. Within 6 minutes heard a clacking sound on one side! And misfire through one of the side exhausts. Pulled the valve cover to see if roller rockers were hitting the valve covers. Nope as we suspected... pulled the intake manifold and cam and lifters fried!!!!!!!! Big pain in the ass!!! A word of caution for those rebuilding their motors "do not use flat tappet cam and lifters! invest in a roller cam setup or break in your motor outside the boat. This is really dissapointing to invest all this TIME and money only to have a major failure...in mid summer!!!! Comp cams have been having issues over the last year their only warranty is they'll send you a new cam and lifters...what about the 500 bucks to remove the motor and another 1200 to dryfit and align...again! Not to mention the time I lost. I had full oil pressure before the start and the engine was primed manually and the guys who built my motor are PRO's who have been doing this for 25 odd years. They are nice enough to correct my problem since they recommended the Comp cam. So now I went with a full Crane roller cam setup. Alot more expensive $1100 roller/ $300 flat tappet but the roller is worth it. Just for the reason that there is no cam break in. I know tonnes of engines use non roller cams and can work flawlessly but with the increased number of cam failures lately its not worth the risk.
Just my 2 cent based on a real experiance!

#1 what oil were you using for camshaft wear-in?

#2 how much valve spring pressure are you running?

[Donziweasel]

Conyo- I am about to do the same thing, but with a roller cam. Hope I have none of the problems you did. I own a transporation company with over 50 vehicles and have blown a few engines in my day and I can definetly feel your pain.

Rootsy- Engine is out. Thanks for the advice, all is going well so far. Tight in the bilge of a 16.

[turbo2256]

If I remember correctly the aluminum heads have a bigger port volume. That means you have to turn a higher RPM like 6000 or better to make best use of them. This costs you low and midrange torq and gains you a small amout of HP at top end. Myself I look for massive torq. I can spin a bigger prop that way. Keep the RPM down to a level the drive can handle. Better fuel economy. As for the weight save in a boat its like an 18 lbs weight reduction = 1 HP or something like that. Another issue less weight raises the stern and sometimes a speed loss unless a spacer is added to get the prop back down in the water. I would also recomend porting iron heads by a good shop not one that just hoggs them out. This increases the air speed and along with a low duration at .050 lift lie not more than 220 and a lot of lift .500 or so. You will greatly gain buy the high air speed less overlap building higher cylinder pressure gaining big performance, economy and emission improvements.