Yea have read good things about the A1000 and how well it holds up, it is a stout pump for sure. Definitely happy about the new set up, and feel more comfortable with it, as we all know the blue pump has its issues, and a dead head is simply put not an ideal set up.

Another little more budget minded 454 mag hop up I helped wayne272 from oso put together a couple years ago.

He had stock 454 365HP mags in his 31 Bullet. Obviously, he wanted to go faster, like we all do. And, like most of us, he was on a budget. His combo is as follows.

Stock crank and rods, .030 over with Speed pro L2399F pistons. Compression came in around 8.8:1. Stock GM iron rectangle ports. Due to budget purposes, a flat tappet was kept. Crane #134561 236/246 114 LSA .551/.571 lift. Crower cam saver flat tappet lifters. Weiand 177 blower with 800 carb

By no means a maximum effort build, with the Chevy heads and flat tappet cam. But a nice cheap upgrade from the 365HP engines, and most importantly, they stay together. 600+ ft lbs at 3500rpm isnt too bad for this little low boost flat tappet 454 engine with the big rectangle chevy heads that dont flow very well. For the most part, its basically a cam swap and bolt on deal that picked up around 200HP per side. Boat picked up a little over 10mph so far and still not propped ideally.

Spend all this time and money to make sure everything is set up right and then mismatch heads and intake. That`s hackery.
To me it wouldn`t even be a question, of course I`m going to sell the mismatched intake and take those proceeds to get the RIGHT parts.
I have a whole bin of incorrect/mismatched parts from my motors.. did it work? Sure. Was it right? Hell no!
Do it right or don`t do it at all, that`s my motto.

I'm a Mopar guy myself (yes, my 10 sec ride is sbc powered as well as is my boat... BBC... but my SRT8 still keeps my Plumb Crazy Purple blood flowing), and the subject comes up often regarding what's better; big block Mopar vs big block Chevy. Really what it comes down to is design. The Mopar doesn't need as much air to make power as does the big block Chevy needs (the Mopar is actually a more modern design) hence the big block Chevy responds to really big cylinder head flow upstairs. Point being.... this is why there aren't a lot of available oval port blower intakes available... I mean, why would you cram all that air into port that cannot perform at the upper rpm needs for which the competition big block Chevy was designed (and where the blower application is aimed).

Anyway... I'm half drunk and ticked off about some stuff (not forum related) so I think I'll be quiet for now. ;)

tom,if you are half drunk you need to finish the job,lol.

Working on it!!!

thanks,,I needed the laugh,,carry on.

whats the beverage of the night?

Corona (a lot of it) lit it off.... wine with dinner. Back to Corona. Priming the system for game day.

I would hardly call the port mismatch "hackery" lol, is it Ideal to have everything perfect port matched sure. It would take hours to modify the square port intake to match, but for what gains? Its already been stated that the gains aren't worth the time/effort or money. Do you have any data to support other wise? Will not port matching make the engine less reliable or cause damage to it? What is the exact benefit or gain power wise or performance in the boat to port matching the intake to the head in this application? What makes this "Hackery" and so wrong to you? Data supporting what you are saying would be ideal, cause it has already been said that its not worth spending the money for an oval port intake or the time and money to modify the square port intake to port match by someone that has the experience to support that answer.

Mike I still haven't gotten a response from you on why I shouldn't use a MLS head gasket on my build?

i just thought that because as you said it,s a budget build that you could use the money saved by useing a gasket like the fel pro marine on something else.an engine build in this hp arena does not need a mls gasket.

I don't believe he thinks you should not use them, it's just just a lot of gasket for minimal boost.

Lol, you just answered it. What he said.

There was a budget for this build in the beggining, that fell apart pretty quick. The gasket was apart of the build from the gate, and it's not anything significant in cost between the cosmetic MLS and a felpro, I'll spend the extra $70 to run the best head gasket on the market.

You think a MSL is the best gasket but they can be a finicky *****.
Its ridgit, by design it can`t make up for any imperfections in the mating surface. Better be sure your surfaces have the correct finish are completely smooth, flat and straight and hope that when you put them in its an extremely clean environment.

Do I have any data? Why do I need data?? I don`t see any data from your sources either except some one word replys and we`re all supposed to bow down and take their word as gospel? Not me, no man knows it all and I make up my own mind.

Heres my data:

http://image.superchevy.com/f/955849...05_rat_3_z.jpg

Does that look right to you? Nice wall the air hits , that looks great for air flow and turbulance .. good luck with that.

Do you really think that square port intakes weren't used on oval ports all the time back before oval port intakes improved? So every oval port head are the size as the ones pictured? What heads are those that are pictured there? Those ports look pretty small. The mismatch will be assessed, and if it isn't acceptable the transition will be smoothed out a little to make it acceptable. Is turbulence in the intake always bad? I have good information that it's not always bad.

Dan. as far as imperfections... there better not be any, lol... if so you deck the block, or mill the heads. and clean environment... if a guy is putting together a motor in a dirt floor shop or outside, well he shouldn't be building high buck motors........... maybe tractor motors. The other thing I have noticed with MLS gaskets in marine use is that guys tend to wipe out impellers and overheat engines. The MLS gaskets seem to act like a spring .... whereas when the motors overheat, expand and then contracts, the MLS seems to hold up better then a regular gasket.

They're also easier on the surface of the head long term, which will result in less material having to be removed when it's time for a freshen up.
As far as the mismatch, why don't one of you Internet engine experts take a look inside the intake port of a Whipple intake with the intercooler installed. Or do a little research on what's actually going on with airflow in an intake port. Do you think it just flows through in a continous direction like water through a hose?

Every single engine build has compromises of some sort. You have to evaluate what is worth spending extra resources on, and what isn't.

They can leak...Some guys put em on with dry others swear by cooper spray a gasket or hylomar, some others take the layers apart and spray each layer,some put rtv around the water passages ... Felpro used to put a Viton rubber coating on theirs but I did not see it on mine .. you need a 50 RA or better surface. My point is if you don`t need it, you don`t need it. I contemplated not using it on mine after reading some of the issues people were having.It`s a better gasket for sure but it come with some quirks.


Edit:
I`m sure the mismatch is fine, it`s just something I would not do.

Pretty sure if you pull the intake on Merc's 7.4L/Bravo III "Performanced Tuned" engines from the mid 90's you'll find this exact mismatch.

Gasket selection
 

All,

I will assume responsibility for the head gasket selection.

I advised ealshire of the RA/RZ surface requirements for proper durability of the MLS gasket and they were complied with.

The reasoning for the choice was twofold.

I checked my data. I have entered 142 pairs (284 gaskets) of Cometic gaskets into service in the marine environment. To date there have been zero reported, part and/or material, failures to date. That is a fairly large data sampling that would indicate to me that, with proper handling and installation, this product would insure the highest reasonable expectation of success. I stand by those numbers and would repeat that component selection.

They also offer the largest selection of thickness and bore diameter to optimize the mechanical compression ratio that is critically important to these enhanced naturally aspirated, small blower applications.

Bob

in a build i reciently completed i noticed the port alignment was not real good.this engine was a 509 with gm rect port heads and a 2.3 whipple with intercooler.it made 765 hp and 840 lbs torque so in my mind perfect alighnment is not always necessary.alex,i also am going to mention that your comment[internet engine experts]also includes yourself as you are here responding to this thread.if that comment was made to belittle some of the people who are posting on this thread maybe you should keep in mind that this is the internet and people are intitled to there opinion,even you.

i was amazed when i took one of these apart and found this.just because merc did it does not make it right!

correct me if I'm wrong but doesn't Alex build motors for a living and is his profession? I can tell you that i have heard phenomenal things about him from reliable resources. Grouping him in with Internet expeers isn't only insulting it's flat out disrespectful. That comment right there is why guys like Alex that have a wealth of data and real life experience don't post on forums anymore. I didn't even see that being directed towards you for what it's worth.

Darin Morgan touched based when asked this question on another forum.

Question

Darin...or anybody else;
Why because of results with their testing MERCRUISER uses a Rectangular port B.B.Chevy intake manifold on an OVAL port head with a giant missmatch because in their words, "mid-range torque and top-end horsepower was increased without changing the low-end output".
Ford Marine also did the same thing with using a Cobra-Jet intake manifold on a regular D0VE port size head on their big-block to create the same giant missmatch for somewhat the same reasoning -

WHY did this occur...???

I was told that this mismatch was large enough to create TWO seperate sound wave pulses; can this happen...? Is the runner being ever so slightly smaller than the port better than a perfect size matched transition? Assuming you could get the manifold on in the perfect location.

Reply

The simple answer is No. Having the intake runner slightly smaller is not the correct approach, its the safe approach. Its the lesser of two evils but given both options I would prefer the port and manifold be sized properly and matched perfectly. If the port is to large and not sized perfectly for the engine combination, having a manifold that is smaller than the port can have a band-aid effect on the air speed and help the engine produce power. This was most often seen with Pro Stock cylinder heads in the late 1980s and early 90s due to using larger than necessary square port heads. Many engine builders (as is still the case today) had no concept of proper sizing and tended to over valve, over manifold and over port an engine. They found that leaving a step (most often on the floor) would increase both torque and power. They reasoned that this power increase was due to a decrease in reversion. There theory was only partially correct. Yes it did lower the amount of reversion but it did so by increasing the average air speed in the system not by the blocking effects of the step. I also surmise that there where some atomization benefits to the step as well but that is unproven.
Its all ancient history but I do see some people still using this technique today. With proper port sizing and induction system design there is absolutely no need what so ever for steps or miss matches of any kind.

Another question to Darin

I have a slight lip going into the head port (approximately 1/16th of an
inch) as the intake runner is slightly ported. This was purchased used,
and I was basically too lazy to match the mating port.

Reply from Darin

You can not have the port present itself to the air flow. Period. Don't let this happen. Take all measures to remedy this. There are epoxy resins capable of fixing this with very little time and expense. Never , ever, ever,ever bolt an intake up to a cylinder head that is larger than the port. Its horsepower suicide!

I dropped off all the parts to my builder this morning, we matched up the gasket to it and it's no where near as bad as the one pictured, the bottom doesn't overlap at all, but the top does and requires attention, so it will get the attention it needs and be blended.

at this point in time i wish i never responded to this thread.i am really thinking about keeping my opinions to myself and just say nothing.maybe oso will be better off without the input from this [internet engine expert] as alex put it.

Mike, I've found your thoughts and opinions to be quite valuable. I'm glad that you chimed in, and I've learned a lot (from everyone).

I think that a lot of the bickering and poo-slinging is just folks' dealing not being around our boats and the freezing temperatures. Have to keep the blood warm somehow, right?!

Anyway, that's just my take, but as the starter of this thread, I feel it's important to speak up.

Thanks,
Tom Zell

Tony Mamo
 

In an attempt to mitigate anecdotal, subjective perceptions regarding the Roval line of cylinder heads I thought it best to reach out to the person that designed both heads. Tony Mamo.

These are all his words in reply to a number of questions posed regarding this very debate. He has seen these conversation on other forums and addressed them as follows. He just replied to post this on his behalf;

Bob

265/290
 

First Question:
So I'm going to order some heads next week and I'm still debating between the AFR 290 oval ports and the 305 rectangles. They both have their pros and cons. I know the 290's will make more power and torque....



First Response to posted question:
Go with the 305cc with the CNC option you can install them in a stroker motor later.







Tony Mamo’s Response:
I would argue exactly the same but insert "290" where you have 305....

The only "con" to a 290 in a comparison of these two heads is price after that nothing but upside.

The 290 has more intake flow....more exhaust flow....and a smaller runner for high airspeed. In short, it will make more power (and especially torque) on any displacement you would naturally consider either to be a good fit on.

Don’t forget guys the 305's are tested on a 4.600 bore and the 290's on a 4.310 bore.....the disparity in airflow is even greater than it looks on paper.

The 290 is an extremely optimized and vary capable small runner.....don't confuse the fact it’s considered an "oval port" into thinking it’s just a good street head. Better to view it as our smallest race head that compliments a small to moderate displacement street engine extremely well. This head flows 370 CFM guys.....I have flowed some 345 -360 cc aftermarket rect. ports that wished they could muster that on a 4.310 bore or perhaps only slightly eclipsed it (with 60+ cc's of volume!)

The rect port design simply has more CSA at the entrance than most of the heads/applications we are discussing need. Till you start moving 400+ CFM's on aggressive engines with very large appetites for air the rect port opening of a BBC head is larger than it needs to be. That’s not where the air is restricted anyway.....it’s all about the bowl and negotiating the turn into the valve and chamber area.....that’s where the port is very sensitive to shape, CSA, and valve job/chamber design.

Ported Vic Jr with a one inch open or possibly tapered spacer assuming you have the room for a spacer.

Perfect intake for that cylinder head
Hope this helps....

-Tony

#2
 

Question;
Tony, back in my motorcycle/sled/watercraft wrenching days, I remember that they used to make these things called "case stuffers" or "reed stuffers". Basically, a molded plastic piece that would fit in the intake port of 2 cycle motors in an attempt to pick-up velocity/airspeed. In fact, the OE's did this.

Would there be an advantage for something like this for the 305's? Seems easy enough to make and install, bet the smaller cube motors would love it.




Tony;
Its called our oval port line.....LOL

The rect port design simply has more CSA at the entrance than most of the heads/applications we are discussing need. Till you start moving 400+ CFM's on aggressive engines with very large appetites for air the rect port opening of a BBC head is larger than it needs to be. Thats not where the air is restricted anyway.....its all about the bowl and negotiating the turn into the valve and chamber area.....thats where the port is very sensitive to shape, CSA, and valvejob/chamber design.

Bottom line is you could epoxy the floors of your intake port as well as your intake manifold exit and pick up ET and throttle response if you did it correctly with the aid of a flowbench to guide you (and alot of time and patience).....or you could buy a kick azz oval port to net you the exact same thing right out of the box.
Ported Vic Jr with a one inch open or possibly tapered spacer assuming you have the room for a spacer.

Perfect intake for that cylinder head

think about what you just said.alex is responding to this thread so that puts him in the [internet engine expert]group.alex is a sharp guy and yes he has a shop and is a professional BUT,i see no need to take shots at the people responding that do not own shops.again just my opinion.putting alex in the group of internet experts is no more disrespectful than the internet engine experts statement to begin with.i have no problem with alex but he needs to remember that you will get many opinions when you bring it to the internet.ealesh,i don,t feel like an arguement today and you have all the answers so i will leave it alone because i have other things to do right now.maybe in the future you should just pm alex and not get the opinions from people you disagree with.

Mike, I would imagine that post was more directed at myself, rather than you.

This whole debate has stemmed from me being told the 305 heads were not the optimal choice in Paytons supercharged 454 build. I simply asked, has anyone built a similar combo, with a blower, and the afr rovals, and what were the results. Why I asked? Because I simply havent seen that build, and honestly would have liked to.

I've seen a few supercharged builds in person with the AFR rectangles, and thought they were very impressive. Upon my quest to seek out the results of using the ovals on a similar build, have come up empty handed. Even on AFR's website, out of the 27 BBC articles posted, several of them being small bore BBC supercharged engines, the supercharged ones were all built with rectangle ports.

Either way, it doesnt matter anymore. The only thing I've gained from this thread, is to simply keep my mouth shut, and stop wasting my time via PM's and emails, when in the end, just be told I'm an incorrect internet expert.

So I ask this of my oso friends. Please do not waste my time asking me too figure compression ratios for you, look up piston part numbers, which bearings and clearances should be used, which blower, which carb, which gaskets, and other things, when in fact, you already have the answers provided by the higher authorities, or plan to do so anyways.. And I say that without any sarcasm. You will honestly be better off talking with the experts that do this day in and day out. I am just a do-it-yourselfer who tinkers with my own stuff, more than builds things for others.

Orlandi Performance
 

Some 500 EFI manifolds mated to the 290 port.

Nice work Brian.

Mike, its no different then doctors, lawyers, plumbers,contractors etc etc, getting mad when us "laymen" guys do what they do for a living....How dare we do that.... It takes away from their importance and can knock them down a notch or two. How else can these guys charge what they do. I have personally dealt with shop owners that were total hacks, and are still in business only because lots of people still do things by price not quality. Don't get mad,I don't think Alex was going after you, and I think you do bring alot to this site. But I also understand where Alex is coming from; There are, and getting to be more keyboard experts on here that opine on things they have no clue about, and even give wrong advice. Its getting to the point on this site that I sit back & wonder what is true and what is BS... I wish more guys like Alex would help out, but they are in the business to make money, not give free advice. Have to keep in mind... Its our hobby & love.... Its their living.

This was the question that started the entire thread. Pretty simple really. I'm sorry that it has evolved and progressed towards what it has become.

As for the plan now... I pick up my parts from the machine shop Friday. The block checked out fine at being standard as did the crank and rods. The rods are being reconditioned to use ARP bolts. I have my bearings, rings, gaskets. 525EFI cam, and the rest of my top-end ready to go with the exception of the springs and super alloy valves (they will be ordered this week). She'll be together in a few weeks dependent on my schedule, and then I'll strap her to the dyno to see what's what.

Thanks to everyone that contributed with trying to help me; greatly appreciated. Sorry that it had to turn into such a b!tchfest between some. I think it ruined what could have been a really informative piece here on OSO.

Thread closed.