Hey Tom, if you are going to reuse those rods, I would suggest installing some ARP wave-loc bolts and having them resized

If you can't move any more air, you squeeze it harder......be it restricted rules racing or blower engines....doesn't matter.

That's the plan!

Tom, make sure the machinist measures the ring land of the Pistons. Just looking at piston that have no marking on the skirts and calling them good can be a recipe for disaster. The lands can get oblonged on the backside.

I had an oso member who's in the process of building a similar 525sc type of build, tell me the 305 AFR's were too big for this build that made 667ft lbs and 691hp . He is going with the Afr 265 ovals on his 525sc build up. It be interesting to see the results of that build. Has anyone done a build like this with those heads ?

Yes

:bigbird: [ATTACH=CONFIG]535994[/ATTACH]

The wise owl usually adds the factual information.this inquisitive bird is thirsty for the info.

You're an inquisitive little birdie aren't you .

Update

My shop called me this morning with good news. Well, mostly good news. My block is good and cleaned up nicely. Only needed a hone. Crank checked out perfect and my rods were all good. Everything is staying standard in terms of bearings. The only bad news was (and I already knew this) that it needs four pistons. I was thinking three, but it looks like four now. He said that he'd only replace one if it was going back together NA, but since it's going to see boost, best to change anything that's even slightly suspect.

Once I get the pistons in-hand, it should be a couple days turnaround time to get everything back. Then I'll start reassembling.

Moving along!

Not sure what youre paying per piston, but it may be worthwhile to just replace the entire set of 8 and be done .

Considering that I'd have to rebalance everything with a new set (the 2399F piston is heavier), this is probably the better way to go.

You are obviously referring to me by this post, and I didn't exactly say that the 305's were "too big", I did ask the reason why you guys really wanted to use the 305's (which was never answered), and that 305 is a big head for a 454, which it is. I never said it was too big.

Please elaborate what you are looking for here? Cause I am interpreting this as a challenge to Bob, and the reason I interpret it this way is cause I may know more about this scenario then an outsider looking in.

I think the thing here, is define too big? Is there a more optimal head out there, I am sure there is. Will the 265 AFR on a build like this thread, make more power, I dont know. Thats why I asked.

Alot of guys here like to talk engines, and criticize others builds. Mike Tkach and I, try to post up data (dyno sheets), in an effort to give something to compare to. No chest thumping, just a couple guys who like talking shop.

My 468's made 800HP and 736FT lbs with 6lbs of boost. With a 308cc cylinder head. Would me bolting on a 275cc cylinder head have made 830HP, and 766ft lbs, I dont know. What I do know, is Mike Tkach's build in this thread, and my engines, made exceptional power for what they consist of.

The reason we, or should I say Mike, wanted to use the 305's? Well, for starters, the engine has a rectangle port blower intake. Secondly, mike witnessed what kind of power my engines made with a 308CC rectangle port, and many other similar builds he has done over the years. Sometimes you kinda lean towards what you know works, especially when you're spending other peoples money. 691HP and 660+ ft lbs of torque with a tiny blower on a 454 making 4lbs of boost, is hardly a bad combination.

I dont think anyone is challenging Bob. I've known Bob's capabilites, and seen him work his magic, for the past 11 years I have been here. I've had many conversations with Bob, and also have learned quite a bit from him. I also helped put Mike Tkach in touch with Bob in the last year. Mike has been building engines since the 80's with no help from anyone, including some big blown akly drag boat engines making gobs of power. Mike has the upmost respect for bob's knowledge, and has now used his camshaft's on the last few builds, as well as purchased heads from him. I think Mike Tkach can attest to my opinion of Bob, both as an engine guru, and as a person, and we both think highly of him.

So again, I dont think anyone here is challenging anyone. But, if we are going to criticize, or make suggestions on what works better, please, lets provide some data on HOW it did work better, not why is SHOULD work better. There are some guys here, that read this stuff, and invest money based on what they read here.

You contacted me for some thoughts on hopping up your engine. Which I tried to share some of my experiances with you. You have a 454 based engine, I have a 454 based engine. You have a 177 blower, I had a 177 blower, I have ran these engines for 7 years, with various combinations of blowers, tune's, etc, with a dyno sheet as well. These engines have never holed a piston, tuliped a valve, spun a bearing, or anything like that. I can only offer the advice based on what I learned, or experianced, when changing from this to that.

I was being honestly curious, if anyone has done a comparable build with the smaller oval ports in a forced induction application. Not because I am trying to prove they are not, but prove that maybe they are. I know what the rectangles can do, it be nice to see what the ovals can do as well.

305's and 265's have the same exhaust port ? IE: Identical exhaust port ?

I highly doubt given all things the same cubic inch, rpm, boost, cam and compression going from a 265 to a 305 there will be any measurable between the two.

No one said your combination was bad, I was just asking a question just like you are here. Dyno results aren't really hard data, and in no way can you compare a single component on 2 builds that have many differences (cubic inches, compression ratio, cam profile, and heads). There are soo many variables that can effect dyno results the only true way to really compare is on the same day, same motor, same dyno, same dyno settings, same builder, and same dyno operator switch the part and re run.

What i am looking for is results from the build.nothing more.if you have the results please post them.

You asked if anyone has done a build with 265's on a similar set up, and he answered yes. He knows what works, as he has done the set up many times. His data isn't a dyno sheet, he knows what the heads flow, and he knows technical data based on head, chamber, runner design, bore size, etc... There are different approaches to a build on this specific motor, we all agree that the 177 is honestly too small, and you can't really build this like a blower motor per say, as it will not perform well blower dependent as we know. Your 420 with 308 heads is just a completely different ball game, and would have zero indication how a 305 would perform with a 177. You add alot of value to this site, and I know none of this information is of any kind of news to you. By big I mean that a 305 AFR based on what they flow and what bore size they accommodate they would be on the upper end size wise for a 4,250 bore, never meant for it to come across as them being too big and a bad choice, cause In reality neither build is a slouch by any means, and there really shouldn't be that much difference in measurable power between the head choices. Basically boils down to there is many ways to skin a cat, and none of them may be bad, but they all have there advantages for whatever the goals may be for the end user.

Mine isn't assembled yet, actually the heads will be here tomorrow, and it probably won't go on the dyno till around early to mid March. I don't care as much of what the number is, i care more about where it makes whatever the number is, and dialing it in. I do have a number in mind, and that is 650hp. Although the builds are similar there are way to many variables that are different to compare a single component plain and simple.

Bob Madara/rmbuilder.....also known as---- "The wise old Owl" ....hmmmm yeah....I'm kinda thinkin' I like that!!! :)

Mike, another situation where I ask myself

"Why do we bother trying to share anything here " . lol

Because it helps the less fortunate like me and does not go unappreciated . :ernaehrung004:

I have noticed in other threads that the mention of the little 265's gets some people as irritated as mentioning how much better EFI is... :)

Seriously though, here is what I can add to this specific topic after literally hundreds of dyno pulls, and in boat performance comparisons to similar sized builds using both heads. On a marine type BBC under 509"s spinning less then 6500rpm, the 265 will make a bit more power then the 305's every time, more peak torque, and more average power, and they're cheaper. I have done direct A to B testing on the same engine without removing it from the dyno too. Unfortunately the 265's give it a compression bump so there is that to consider as well. I built two identical 557's, one with 265's the other with 305's, same cam, same compression, both efi, same everything. The 265's outperformed the 305's up to 5200rpm. I have also switched from the 265's to 305's on a procharged 489 because I wanted to lower the compression to run more boost, and put in a bigger cam to turn some more rpm. So they're not perfect for every application. The 265's have a very fast port, and out of the box have a couple of localized areas that are too fast for bigger cubes, or a lot of rpm. With just a bit of work they'll support 700hp NA though. I haven't used any for a while because I've mostly been building bigger stuff, or LS's, but I wouldn't hesitate to use them any time, and think they're an incredible value.
For a build like Mike T's the performance would be so comparable that it wouldn't be worth changing the intake for though, in my opinion. I'll try and dig up some dyno sheets, but if I post them before I get Bob the ones from the testing I did for Johnson lifters, he'll kill me. So it'll have to wait til I get a bit of free time.

I chose the 305 for 2 reasons.first the existing manifold was rect port,second,if the engines owner decides at a later date to go bigger he won,t need to buy new heads.i will also add ,imo the oval port with a matching intake might have made a little more lower rpm torque but i am pleased with the end results of this build.

Just for the record,for a n/a 454 i would use the 265 in a heart beat.

Don,t take this wrong but i am pretty sure bob will add to this thread when he has time.and when he does it will be with facts,not speculation.

When you get it done please post the dyno sheet.also include all the info such as compression ratio etc.

There are still some of us around that do a boat load of reading conflicting info all over the inter web then come here to see how it applies to "my" build. Keep the good info coming, I hope to someday be able to provide the same to others. Sounds cheesy I know but I for sure am very appreciative of all the help I've gathered from here. I'm out.

I think you guys do a great job and service to this website with sharing your info on here...I enjoy the reads that you guys post.

Ten years ago, I needed some heads for my old 565cid engines. I think I was Bob Madara's first customer....near the end of 2004, I was looking for some new heads...I needed new heads. This is after some guy had sold me into bringing my engines and a buddy's 540cid engines down to him in the deep southern states...hind sight is usually 20/20...not a good idea. I ended up having to go rescue my engines---long long really bad story!

Anyway, after all of that, Bob Madara told me that the AFR 315cc CNC ported heads would really work well on my 565cid N/A engines....and I remember responding to Bob; "Are you sure, Bob???" He also did the cam specs as Dave Wesseldyke re-machined and assembled my engines. I remember Dave being very impressed with Bob's head/cam combination for my engines as Dave ran them on the dyno. It was from that point on that Dave began to use Bob's cam profiles for his customer's engine builds....and now we're using Bob's head/ cam profiles again on my next set of engines that Dave is building.

So, yeah....Bob may be old.....I...I mean the "Old wise Owl"...but he knows a bit about those head and cam profile combinations! :musik010:

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.

Usually a non matter. In fact, on a few NA 454 builds, matching the rect intake to the oval heads lost power.

Sound/look weird ? Sure does. But there is a lot of things that don't look correct on paper that actually work in the real world.

If you aren't building this like a "blower motor" then why in the world would you only have 8.68:1 compression with the 177 blower?

We are building the motor to make good power on motor alone, and not be blower reliant. The 525sc in stock form is blower reliant, and shows it in its performance. You can't rely on a 177 to make your power like you can with a larger blower, and that's what i meant by that statement. And just a question for Black Baja what would you run compression wise in this particular application?

Your build is .030 bigger bore.do you believe that would make a hp&torque difference?.your compression ratio is almost the same and your cam is very close.other than the heads these engines are almost identical.you did not say what size carb you will be useing .my build has a 1025 cfm barry grant.

9.5:1 3lbs boost and you aren't gonna melt it. 8.5:1 454 is a blower reliant motor. I would have to do some figuring on the 9.5 3lbs but that's gonna be a better combination than relying on the 177. As soon as that thing heat soaks your gonna be in trouble. I've ran 9.5:1 5.5lbs inter cooled and that baby was like a rocket. At 7lbs it would detonate. Bobs cam will definitely help the motor out.

No I don't think that the bore and compression will make any real difference, I am using the stock Holley 1050 dominator that has been set up, flowed, and boost referenced through AED. Dyno sheets from 2 separate builders, seperate dyno's even if the same brand, seperate dyno operators, and in 2 different parts of the country are not comparable to say that the 305 made/didnt make/or is the same power as the 265. What correction factor was the dyno set up at? Is the Dyno calibrated? How often is it calibrated? Looks like your dyno doesn't use a water break for load? If my guy ran mine and it made 650 and I said pull it again and make it show 690 it would be no problem. We could pull it and make X, let everything cool down while keeping the oil temp hot, and do a quick blast and I promise you it will make more power then the pull before where we let everything get up to temp. The only real data in this thread is Haxby's post where he has literally tested back to back all the same and just changed the 1 component. Your dyno sheet isn't real data, its a reference, but its not data. If you ran that exact motor with no changes its HIGHLY unlikely that you would get the same numbers dyno to dyno with all these different variables.

Ask any of the builders here and they will all tell you that in a blower application 8.7-8.8 is the ideal compression number and to stay 9:1 or under in a marine application. You are from maryland, call Tony at CMS or Dave Govatus, actually call Eddie Young too. This information was the same between all 3 of them for this application.