Trick Flow Alum. Heads

[Looped]

Now that I have the 3” stroke forged crank on the way it’s time for more parts. Has anyone used the Trick Flow 23 Degree Aluminum Cylinder Heads and have any luck with them on SBC’s or are the Sportsman II’s still a better head even though it’s cast iron? And yes it will be a closed water-cooled setup.

Thanks,
Craig

[BigGrizzly]

I don't know about chevys, but my son put them on his 5.0 Mustang and a vortect then I bored the block he did some mods and got 600HP out of it. I haved looked at many head designes and these are one of the best I have seen. They go without being worked. If bucks are the problem or your less then 450HP and 5500 then do Madpoddtles thing his boat scoots 70+.

Randy

[Looped]

The Vortec's were my original thought but I was looking for something that would do at least the same with less weight and close to the same cost (not that it's much of a weight loss). Unfortunately this motor will handle 7,000 rpm’s (rev limiter security feature) all day long but the outdrive (for now a B1 2” shorty will be it) will not so I need low to mid range torque somehow (the 144 B&M blower has been an alternative)?

BigGrizzly,
Do you mean the Vortec's or the Trick Flow's are the best you have seen out of the box?

Please don’t ask why I did not go with the 383 because I am looking for something totally off the wall, thanks.

Maybe the Vortec’s are the best route?

Thanks,
Craig

[CDMA]

Looped,

If you really want Aluminum why don't you look into the Vortec style "Fast burn" GM cast port aluminum's. Jamesbond used them on his 388 with a lot of luck I believe. I think they are about $1100.

Chris

[Woodsy]

Looped...

I replied to your e-mail before I read this. Definitely go with aluminum heads. Just decide on a course of action blower vs. non-blower before you build. That will determine what size combustion chamber you need to go with. Any time you can remove weight its a good thing. As we say in my business... lightness is rightness! Between the heads and the exhaust you should lose over 100# of cast iron. Also, you will definitely need to put in a killer valvetrain. Iconel exhaust valves, heavy springs & roller rockers. This is going to be great when its done!!

Woodsy :D

[Looped]

Chris,
This whole project is on somewhat of a budget because every thing is being bought brand new; Fast Burns would be a nice to have. :( Since the Vortecs are around $500 and the Trick Flows are about $850 I think that I’m down in that range.

MadPoddle,
It’s basiclly a Chevy DZ 302 motor but stronger than the factory ones so whether I like it or not it’s going to take the high RPM’s. Like I’ve said before, since I sold my 69 RS Camaro I’ve wanted a 69 Z/28 RS so heres one way of partialy having one for the time being. I’m not sure of the Fast Burns but you can get the Sportsman II’s with a straight or angled plug whole and they cost about the same as the Trick Flows.

Woodsy,
After I get the block & crank back from the machineshop I will see what they say that I can get for low to mid range torque being naturally asperated, if it’s not good than the power charger may be the way to go.

Waiting it out,
Craig

[Woodsy]

Looped...

You need to approach the motor as a total pkg. I know you will putting it together as you get the $$$. I also understand the need to be different. My need to be different borders on the masochistic side... I own a Buell. But you have to be careful when planning on building a motor. these are my
guidelines for building a boat motor, take them for what its worth...

There are several restrictions on your selections that are invariable...

1. You cannot spin a Bravo over 5200rpm for any length of time or it will grenade. This is indisputable... kinda like gravity

2. Small displacement motors make very little torque (comparable to larger displacement motors.

3. Small displacement motors make great hp at high rpm. Unfortunately, this does not help. See rule 1.

4. Reversion seriously limits your camshaft selections.

5. Boat motors need torque to turn a propeller. You need to tune your motor so that peak torque is approximately 200-300 rpm under the limits of your outdrive. Mercruiser sets the rev limiter at 5050rpm for a 502-454 Mag motors. This is 200-300 rpm above torque peak. Although the hp actually increases after this rpm, torque drops off and subsequently the boat goes slower. The biggest prop you can spin at this rpm will give you the best speed... of course you can tune the prop for holeshot, midrange or whatever, but as a general rule the biggest prop you can spin at the torque peak of your motor will yield the highest top speed. The flatter the torque curve the happier you will be.

Now, I know you are building a 302ci Chevy. Basically a motor that was designed to rev to the stratosphere and make some serious hp up there. But, because that doesn't really help you in a boat, you are in a bit of a pickle. You need to choose the cam & heads very carefully. I looked on the web, and alot of these small block heads, are really designed for high rpm operation. Raised exhaust ports, large intake & exhaust valves, intakes optimized for high velocity flow etc... You need to make your selections based on a 4800-4900rpm peak torque. Look at the flow sheets for the heads. A set of tricked out heads might actually hurt you more than help you.

The camshaft is the brains of the operation. A camshaft for a normally aspirated motor will have a different profile than one for a blower. The profile of the cam will determine the characteristics of the motor. You also need to worry about reversion. This will seriously limit your camshaft selection. The stock cam specs used on a 350 Mag might be a pretty good starting point and fine tune it from there.

Given the above constraints, I would guess you could get about 225 to 250pshp from your 302 naturally aspirated. probably somehwere in the vicinity of 175-200ft/lbs torque @ 4800rpm. These figures are just guesses, based on my experience and what I have seen from various mfg's. The 350 Mag MPI only makes 300pshp. This puts your boat in the low to mid 50's speedwise. A blower will definitely add 75 to 100 ponies, but more importantly it will add about 75 -100 ft/lbs torque across the rpm range. This will bring you up into high 50's, low 60's speedwise.

All this gibberish boils down toplan very carefully and plan ahead. If you want a blower motor build it as such. Compromises very rarely work out well.

Just my $1.50 worth. Please feel free to pick this apart.

Woodsy :D

[CDMA]

Looped,

I know the budget thing...mine comes down to if I buy this boat part can I buy pencil lead??? Lucky it is free at school huh :rolleyes: :rolleyes: :rolleyes:

What Woodsy says are some really good points. It looks to me like a blower would be a really good option. Heck if I remeber right you need to recore your 18 so would it be a crime to just get a monster 6-71 out the hatch...that would look cool. I have to say that when I built my 18 I had never ridden in one and I had this I want it to look cool attitude and speed and handling was secondary. However the more I used my boat and if you really plan to use yours I really wanted a boat the handled better and was even faster. I think a really nice speed for an outdrive 18 classic is in the 70 or so mph zone. ( my guess is that about 400 hp would do it) Even when it is glass calm you still feel like you are moving. Quiet frankly at 60 mph with no wind it can actualy feel slow.

If you are dead set on the 302 which I can completely understand I think there are two ways to go about it. The first would be to make a little screamer but that can be more expensive than a blower motor. To get some really good power out of that little displacement you are going to need good heads, exhaust, intake all of which really adds up. Then not to mention you have to rev the heck out of the bravo. From what I can tell my belief escpecially with SB power you can rev a Bravo a bit more than 5200 rpm but it still gets into the questionable area. So by the time you get good heads ($$$), exhaust($$$) and intake ($$$) you might be better off just building a more stock style base engine ( 302 ci) with a blower on it. Drop the compression down with some blower pistons and crank the boost up. It sounds like you forged lower end should be able to take it. I am a big fan of intercooled systems but I know we are getting back to the $$$ area again. If you like new it is another story but I just got a 1999 procharger M1 with 40 hours for a BBC mag for 2K. If I put that on a 454 mag I immediately get 525 or so hp. To get that on a NA engine I would need the same upgraded parts that you would need on your 302 ( heads, exhaust etc). And for my application new heads alone can cost close to the same price the supercharger did. This also gives me a lot more leniency with my cam profile and I don't want to say cut corners but I can still uses less exotic/expensive parts on the base engine. Not to mention then if I ever get really bored all I am is a 540 ci long block away from 700+ hp.

Just my .02.

Chris

P.S Woodsy you don't think you could get 300 hp out or a 302 without going wild? this may be bad logic but you can get 350 out of a 350 without going to crazy and take equates to 1 hp per ci. Wouldn't it be safe to say that that same ratio is doable with a 302? I know it is a ford but forrest's little pocket rocket gets closer to 300 hp I think.

Blowers are cool

[Woodsy]

Chris,

I was going for pshp... If you get 300pshp out of a 302, given the restrictions for camshafts and rpm I would be very surprised. That would put you at well at about 350 hp at the crank, then you lose about 30 to spin the bravo and another 20 for the ps pump, water pump, alternator etc. I think this motor will have profile very similar to a 5.7 275 hp motor.

Woodsy

PS:Like you said "Superchargers are cool!" :D

[Looped]

How did I know that Woodsy would come up with something like that? Just the stock 302 had around 290hp @ 5800rpms & 350hp @ 7000rpms with a duration of 229/237 that’s not too far away from the 224/224 approx. limit (it actually had more but I will stick with that) and I’m sure I can get 375hp at the 5000rpm range (the “under the hood” 144 power charger would do the trick but 1,900 bucks later). I’ll just have to wait and see what the specs come out as on paper to see what the possibilities are.

Just the whistle of a blower is cool.


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http://www.donzi.net/photos/lwdc10.gif

[CDMA]

Sorry Woodsy I missed the pshp.

Chris

[Woodsy]

Looped...

I don't mean to sound like a jerk, or a doomsayer, but...

You have the cam specs right. The specifications for the cam are .452" intake and .455" exhaust lift, 229 degrees intake duration and 237 degrees exhaust duration (both measured at .050" tappet lift) and 78 degrees of overlap (at 0 lift). Although the numbers on the duration look slightly higher than the recommended 224/224 for marine use, actually they are quite a bit off, reversion is almost certain, unless you run a dry exhaust. This is a mechanical camshaft as well. SO you might find a little more power in some revised ramps using a roller cam. The hp is right 290 @ 5800rpm, but you forgot something....

The compression ratio on the original 302 was somewhere around 11:1. You will never be able to run that today. And that 290hp was rated at 5800 rpm, 1000 rpm higher that you will be spinning in the boat. All things being equal if you can get a 1:1 ratio for displacement vs crankshaft hp (302ci/302hp) with 8.5 to 9.1 compression @ 4800-5000 rpm, you are doing pretty darn good. Then you have to subtract your parasitic losses. This setup also produced 290 ft/lbs of torque @ 4200rpm. But it was with 11:1 compression. I still think my original figures are pretty accurate. I don't want to or mean to be a naysayer, because I think you are building a really cool boat, but I think your hp expectations are a little unrealistic. I would hate to see you spend your hard earned money and be disappointed in the results.

Check out this website... http://www.holisticpage.com/camaro/camaros/302.htm

Woodsy :D

PS: My info was stolen form Year One's Camaro restoration catalog...

[GEOO]

Looped,

I'm sure the Trick Flow would build good power. However, don't buy any set of heads pre assembled. Boat's need better valves; and the spring need to match your cam. I run AFR 227cc on my small block. Manley Severe duty intakes, Inconel Exhaust. GEOO

[BigGrizzly]

I did mean the Trick flow were the best non modified heads I've seen.
Geeo is right, however Our Trick flow had had the severe duty valves in it already. My son nevered pulled his 5.0 passed 5500 to get 600HP with his blower motor.on anither note Forrest has his Little Green Giant a 16 with a 302 Ford a 500CFM carb engine running at just about 70 mph. and no blower and no reversion. For speed what you need is upper end Torque--about 3900 ->5000 Rpms and it is attainable. I knowwhere there is one right now that is ready to go- dynoed and all.
Randy

[Looped]

Geoo & Big Griz,

Thanks for the tip on these heads, unfortunately Trick Flow only sells them as a pair and as a ready to bolt on with valves, valve springs, locks, retainers, rocker arm studs, and guideplates. It would be a waste to replace all of these parts so I will be calling them to see if they do sell the heads bare for a special order just for more options for me.

For now I will slowly build this motor (no hurry on this end because the older it gets the more of a Classic it will be once finished) instead of buying a complete one because I have a HUGH project coming up once I start on doing all of the balsa, stringers, transom, etc…(CDMA & PaulO are first hand witnesses to this). Around 70mph is a good goal for me and especially since the Classic is about 35 years old I would like to keep it in one piece.

Thanks again,
Craig