Originally Posted by airjunky (Post 4255621)

Ill be a monkeys uncle if someone actually rolls into this thread and says "yea , i put a 250 on a 454 with big brodix aluminums , blower cam found the best balance at x boost with y upper anz z lower pulley " nah prob not lol .might have to spool it to make 5 pounds , but with those heads and a good exhaust , it will be a good 5 pounds and it should still start to come alive by 2500 or so

Originally Posted by MILD THUNDER (Post 4255404)

Mark, as BS aside, I am excited as heck for you, to get these engines in the boat. We know what it ran with the 420 combos, and I think you are gonna be extremely happy with these two new engines in your boat. You did an excellent job on last years interior makeover, and now you're gonna have some sweet engines to push that boat to speeds it's never been to. You did it right. You didnt cut corners, trying to reuse old pistons, rods, half azz machine work, reusing old heads, and what not. You spent some coin, but I feel you did it right. It makes life much easier for the guy doing the assembling and what not, dealing with someone who's willing to take the steps needed. I've seen way to many guys want to cut corners, and not only does it make life hard for the builder, it usually comes back to bite everyone in the azz.

I would like to come down with Mike to help dial it in on the maiden voyage if thats cool with you guys.

Originally Posted by ealesh33 (Post 4255049)

The correction factor is to simulate that the conditions are X everytime, and there are a couple different formuals that can be used, one of these formulas your dyno uses to take current conditions and make adjustments to the output to simulate the X conditions. I never mentioned changing the correction factor, nor does my guy try and hit numbers at all. My point was a good dyno operator can minipulate the machine to make damn near any number you want. You can also do a quick blast while the motor is cooled down, but the oil is still hot to make more power on that pull. Ny guys dyno is known to be on the conservative side.

Ill give you a good example, and this is an example that Bob gave me the other day. He spoke of a builder that his dyno is very conservative, on any given day you could put a motor on it, and then take to another dyno and run it and the motor would make 30-40hp less on his dyno then the other, its just the way its set up. And in reality the "number doesn't matter, the dyno is a tool to tune, make sure there aren't any issues with the motor, and also to find where peak power is.

A good question is in order to make 691hp 667ft lbs with this set up, what do you think this motor is making NA to get those numbers?

Originally Posted by ealesh33 (Post 4255128)

I don't have all the answers, not even close, but i figured you would have some more answers then you do, as I thought you were an engine builder? i may be thinking of someone else but I thought I read you have been building motors for 30 years? I don't build engines, I know a little about a little but, but like I said I'm not a builder. What kind of builds have you done with 454's and what kind of power did they make? Is this the first 454 with a blower or 177 you have done in 30 years? I'm here for the same reason you said you were, I'm looking for data.

I mean if you take some figures into play like each 1 lb of boost equals 25hp, that's kind of a blanket round statement but it's also referring more so to a bigger blower then a 177. Also have to take heat into effect, and with a 7" bottom pulley to 3.25" blower pulley you are spinning the blower 12,923rpms, From general reading the 177 is a 13,000 max rom blower, but I can't say how factual that is, and if I recall correctly i think it was Joe that posted that somewhere. On a stock 525sc that blower spins roughly 11,200 rpms makes 5-5.5psi of boost and adds roughly 120-125 hp to the 420 merc platform which kinda supports or is pretty close to that 25hp per 1psi of boost theory. Now there comes a point where the blower is starting to generate more and more heat and I'm sure that hp per boost starts to fall off, that's just a theory though. so if we use that figure 25hp per 1psi of boost and I think tthat's a little generous for this blower spinning at that rpm, at 4.2psi of boost would equate to a 105hp. Based on that thinking then without the blower the motor is capable of roughly 586hp NA. I am very curious how close that estimate is honestly, as I don't have real data to back that up. I'm sure there may be some variables that I may not be considering

Originally Posted by MILD THUNDER (Post 4255720)

HP per lb of boost has several variables. Temperature in the manifold, parasitic loss from the blower, and so on.

On a build like this, you can have a procharger making 4psi, a Whipple making 4psi, a roots making 4psi, and have very different numbers at the flywheel.

Originally Posted by ramos45 (Post 4255742)

Joe - you mentioned earlier the risk with small blower and small intake. I'm about to take the plunge into two 177 blowers. My cam is 227/233, 613in/ 598ex on a 114 Lsa. Oh and brodix aluminum heads right at 9.0:1. Would running these blowers at under 5psi be off concern?

Not trying to hijack, just one question.

Originally Posted by airjunky (Post 4255797)

....and his female passengers will still be able to sprawl out on the engine hatch.

Originally Posted by MILD THUNDER (Post 4255737)

Adiabatic efficiency and parasitic losses are two different things of course

Originally Posted by ealesh33 (Post 4254609)

The differences in my build vs your build are as follows

Bore - 4.280
Compression - 8.68:1
Cam isn't done yet but Bob ran some numbers by me that it would be - 654/63? lift, 231-235 duration on a 112LSA
Heads - 265 oval port with CNC chambers

As far as the intake goes I have a rectangular intake as well, not even sure there is an oval port intake for this as I haven't looked. I was told it won't make any noticeable difference in my particular application by 2 sources, but was told what we can do if I am concerned with it.

Originally Posted by Budman II (Post 4257736)

FWIW, I was told that it was less than ideal to run a rectangular port intake with the "roval" ports on the 265's. I was a bit disappointed with this because I had a very nice Merlin single plane with the brass water passages that I had wanted to run. Ended up with a Dart oval port single plane. Optimal combo with these heads would be an oval port intake that is port matched to the intake port contours. You can get the correct intake gaskets from your Chevy dealer - they are the same ones that they run on their aluminum Edelbrock head engines - think the ZZ502 runs them.

Also, I think there is a GM Performance Products dual plane intake that has the correct port shape, but it is expensive. If you want single plane, an oval port that is port matched is your only option, as far as I know.

Originally Posted by HaxbySpeed (Post 4258058)

Holley/weiand makes one. It's pretty $$ though, and probably not worth anything for what you're doing. I used one years ago on a 525sc with eddy marine heads.

Originally Posted by ealesh33 (Post 4257742)

I have A 177 weiand blower, your traditional intakes won't work. I haven't looked very hard for intakes as I was told by my builder and Bob that I won't see a difference in my application, but I haven't seen an oval port intake that accepts my blower

Originally Posted by MILD THUNDER (Post 4258127)

They are not cheap manifolds that's for sure. I know many have ran rectangle port intakes on oval port heads and it works. However I've never seen any data on if switching it for a port matched intake is worth power.

I have a slight mismatch from my rect intakes to rect heads as the ports are slightly different shape. It drives me nuts knowing its like that lol. Sooner or later I plan to pull them and do a nice port match. I wouldn't be able to sleep knowing I have a big rectangle port intake on an oval port head.

Have you seen any hard data that "it doesn't matter" for your application ?

Originally Posted by MILD THUNDER (Post 4258127)

They are not cheap manifolds that's for sure. I know many have ran rectangle port intakes on oval port heads and it works. However I've never seen any data on if switching it for a port matched intake is worth power.

I have a slight mismatch from my rect intakes to rect heads as the ports are slightly different shape. It drives me nuts knowing its like that lol. Sooner or later I plan to pull them and do a nice port match. I wouldn't be able to sleep knowing I have a big rectangle port intake on an oval port head.

Have you seen any hard data that "it doesn't matter" for your application ?

Originally Posted by ealesh33 (Post 4258252)

is it worth spending $680 for an oval intake, or the time and money to modify the square port.

Originally Posted by HaxbySpeed (Post 4258262)

No.

Originally Posted by MILD THUNDER (Post 4258269)

I agree. Esp as I have no data to show the difference between the two on an oval port head with a blower.

Another interesting thought would be whether you would have been better suited with the small rectangle head and your intake from a cost and possible performance perspective.

I could be way off, but I've always been schooled that there is more to flowing air than just the area between the intake valve and the intake flange of the head. The runner shape and size plays a role, from the carb/thorttle body to the head flange as well. I would think you would not want air flow to be hitting a dam and tumbling thru the port. But that may be a question for someone who has tested these theories and whether or not they beared fruit. Or like you said, whether or not its enough to matter. I personally think we spend the time worrying about 2 degrees of cam duration , .600 vs .630 lift , .025 in pushrod lengths,, and. 2 tenths of a point of compression on our builds , so why would we just say "screw it, the port match sucks, but let's run it".

Originally Posted by ealesh33 (Post 4258277)

Well I don't think we are saying screw it the port match sucks, just run it. Its more of a budget thing, and where the money should go within that budget. Would you rather spend $680 on an oval port intake or a set of morel lifters? Where is the money better spent when it comes to budget, and that answer to me is pretty clear, specially on something that is said to have very little effect on the end result.

Originally Posted by MILD THUNDER (Post 4258291)

Understood. That's why mike and I leaned towards the 305 AFR as the engines had the 177 rectangle intakes. Maybe the 265s and port mismatch would have been the better way to go. We'll never know.

But in your case the smaller chamber helps you out with those dished pistons . that's a bonus.

Originally Posted by ealesh33 (Post 4258322)

Yes having the ability to do a 102-112 CNC chamber was a positive for us, and one of the reasons we chose that head. With the 305 flat milled the lowest you could go is 114 with CNC chambers. We ended up at 106 with CNC chamber, so not sure what the compression would have ended up at with a 114 cnc AFR, and that would have left no meat on the head. We could have went even smaller on the chamber, but I thought it would be a good idea to leave some meat on them

Originally Posted by ealesh33 (Post 4258322)

Yes having the ability to do a 102-112 CNC chamber was a positive for us, and one of the reasons we chose that head. With the 305 flat milled the lowest you could go is 114 with CNC chambers. We ended up at 106 with CNC chamber, so not sure what the compression would have ended up at with a 114 cnc AFR, and that would have left no meat on the head. We could have went even smaller on the chamber, but I thought it would be a good idea to leave some meat on them

Originally Posted by MILD THUNDER (Post 4258395)

Should be a nice upgrade from the 525sc combo. What fuel system setup do you have?

Originally Posted by ealesh33 (Post 4258448)

When I bought the boat in August it had a red holley pump on it full flow, which wasn't sufficient, so I replaced that with a holley blue pump with dead head regulator. With doing this build I picked up an A1000 pump, going to run -10 feed to the pump with a aeromotives pre filter, -8 out of the pump to the carb, aeromotive regulator with -6 return.