What heads for my small block
 

I am still collecting parts to build up my stinger 202.
I really like the dart Iron Eagle heads, I've caught some good deals on the 165CC runner, or the 230CC runners..
I am building a 350 with all new forged internals, and an XM262H camshaft..

Are the 165's too small? Are the 230's too big?

You already have those heads or just considering them?

Why not the vortecs?

Two reasons...
1. I really wanted my motor to be all new... nothing rebuild or used..

2. For the money I can get a set of vortecs to flow like this
.200" 136/109
.300" 193/158
.400" 239/198
.500" 273/208
.600" 289/214
.700" 293/219

Look into these
 

The newer Bowtie Vortec Heads are stated to be the best iron SB heads from GM. Performance as good as many CNC aluminum heads right out of the box at fraction of the cost.

I don't care whose doing them a vortec head will NEVER flow those numbers.

When looking at flow numbers don't look at numbers past .5-.6 since you'll never see that much lift depending on the cam. You want the best flow numbers possible when comparing intake/exhaust runner size.

If two cylinder heads have the same flow numbers but one has a 195cc intake runner and the other has a 185cc intake runner, the one with smaller runner will outperform the larger one due to increased velicity due to the smaller orifice(air moves faster through the cylinder head). Thats why the bigger the head you go the less low range power/torque you have...because air flow speed through the cylinder head is low because the runners are so large.

Lets back up a bit.

What kind of drive system in a "stinger 202"?

How much does it weigh? If you get past 70-75 with a heavy boat it want to run anymore without hydraulic steering - have you provisioned for that?

What kind of HP and torque are you expecting to get at what RPM range. what kind of exhaust are you going to be running - the factory stuff will flatten your engine and choke it so you will need a good aftermarket exhaust.

Aluminum vs Iron heads will either save you possible detonation if you get a tank of lousy gas (always a possibility with a boat) r let you run more static compression to begin with.

If you have the short block apart you might as well build in some bigger cubes.

I have much experience with small blocks and boats.

Uncle Dave

The AFR 180's offer excellent bang for the buck on a 350. You can check out the dyno sheet on this thread.

http://www.offshoreonly.com/forums/g...i-upgrade.html

That is a nice little package for a 350. Leave the bottom end in the boat and slap on a new top. Probably the way for this guy to go.

I see the base reading is at 3400.
Was there an issue stabilizing at 3K?

I spent a little more money on a this 406 combo and its pretty neat for a few bones as well. Idles like a kitten.

Uncle Dave:

Those are excellent numbers and results from a 406 small block!
If this boater can get at or close to those numbers from his small block using your specs and examples, he will be a very happy camper!
Learn and profit from someone else's excellent design and results and you will be way ahead, don't re-invent the wheel!

Best Regards,
Ray @ Raylar

No it was great down low and idles strong. That dyno didn't have enough water supply for long pulls. The 406 is a great combo the 434 works good too. I like small blocks :coolcowboy:

Thanks Ray.

I have to give the credit for the combo to the engine builder. An old drag racing guy named Dick Gazan thats been doing it since I was forming eyelids.

Your LSM 550 is an awesome package I would love to have the money to buy!


UD

Wow thats a nasty piece for sure! Big fun.

Im guessing it needs race gas and is setup for car though.

I asked my builder about a 430+ setup and he told me they make great power but have issues with wear which I thought was strange, but recited stuff about getting there with stroke causing rod angle issues.

I was originally interested in 454 SB short block with my heads, but stuck with my old "garage special" 406.

UD

The boat is quite a project.. and I am taking it one step at a time. from the inside, out

Im not sure what the boat weighs... but I towed it home at 80 mph behind a 4cyl toyota tacoma.. And it was lifting off the trailer. So, lets just call it light...

I will be dealing with the drive system later, it had through hull exhaust and I will be looking for higher flowing manifolds later on in the project.

I have a displacement limit on my lake at 360Cu in..

Id rather pay a little extra and get an all new head than deal with digging parts out of boneyards that have been well used up and need a lot of work done to them.

So let's limit this to aftermarket Iron heads.. 165's might be a tad small and 230's are probably too big. Am I wrong on this?

Nope, pump gas hydraulic roller. Going on it's fourth season now. The 454 small block isn't a great combo but if you do the
434 right it's no problem. For forced induction I like the 406 better.

I think you are right. 165's will be too small - and 230 too big.

I wouldnt expect any real gains until you do the exhaust manifolds with a quality aftermarket unit - so Id try to save up and time it so they both get done.

( SB marine exhaust is one of the harder components to find used)

I ask about the drive because Im suspecting its an i/o which means the unit needs to idle at around 800 RPM which means no big cams/ head ports or runners.

UD