sounds to me like someone doesn't want to pay the $$$ for a dyno session. I'm glad I did, and I like the results. I'm also glad I chose Mike to build my engines. I think the combination he and Bob came up with is working very well with the blower I had and my desire to run on 89 octane.
I really have not figured out what your complaint is. There are other combinations out that and good reasons for them. Go with them. Good luck.

Sounds like your correct.....

I bet he's reusing rings and bearings also.....then when his engine blows he will blame bobs heads!

Its crazy that this is where this lead, but this is how OSO works, have seen it time and time again here. A bunch gang up on 1 and it derails to a completely different direction. This combination that Mike did for you is a great combination, and like I have mentioned before and you mention here there are many options, and plenty of great reasons to go one direction or another. I have zero complaints at all, in general discussion something I said was misunderstood to mean something that wasn't intended between me and Joe, I was informed about the post made here, so all i did was explain that it wasn't what I meant. It somehow got here Also people like to skim through, not really absorb everything that was said and then post dumb comments. I am sure you will love your set up, and with my set up being very close to yours im not sure why anyone would think that I would have any kind of complaint lol

And Dyno'ing is a must, I never even considered not doing it!

Lower end was just completely redone prior to the decision to do these upgrades. So you would lose that bet.

Heres a good article. They took a 489 stroker, 9:1, 261cc oval port aluminum heads, with a 236/246 550/571 lift flat tappet. This setup made good power in my opinion. With the blower driven at 2.10, the engine made 661HP at 6000, and 698FT lbs, at 4000. Registering 3lbs of boost. So they spun the blower harder, to make some more boost. Now they had a 2.46 ratio, to make 5lbs of boost. Engine made 700HP, and 750 FT lbs. However, they noted the blower case was getting extremely hot, and the belt was beginning to slip. Basically, the blower had its tongue hanging out, and was spinning faster than its max RPM for longevity. Thats on a dyno pull. What do you think happens in a boat if you were to hold that thing WFO for miles at 2.46 overdrive?? What you would see is probably extreme power drop off at wot. That 700HP, would probably drop to 690,680,670 etc as the air heats up, the blower case grows, and tolerances get bigger. I know someone who's witnessed it first hand on a steady state dyno pull with one of these small blowers driven outside their recommended range.

So off came the 177, and they bolted on a weiand 8-71. Which really, from an 8-71 standpoint, isnt that great of a blower compared to a littlefield, hampton, etc, but irregardless. At 25% underdriven, 4.8psi of boost was made. Engine made 717HP, and 674FT lbs. So, what happened here, was the torque fell off quite a bit in the midrange, but it did gain a bit of power up top. Next pull, they upped it to 17% underdriven, which made 6.4psi. Now the engine made 766HP, and 724FT lbs of torque.

What do I conclude from this article? Well, a couple things. Obviously the 177 makes heat. But it also makes torque. It doesnt take a ton of power to turn, and the fast rotor speeds seem to really boost the low end output. The larger 8-71, trades off some torque, for a HP gain up top. Plus, the ability to run a little more boost, since the air charge would be substantially cooler than the smaller blower.

If I had a street chevelle I wanted to run around town with on saturday nights, you betcha I'd go with the smaller blower, and better low end torque. If I was installing it in a boat, I would much rather have an extra 100HP at 6000RPM. You'll be able to swing a prop of probably 2-3 more inches of pitch with that extra 100HP, which equates to faster top speed, and faster midrange cruise at 3000RPM.

My opinion on all this, is arguing over the 265's vs 305's, is not really what we should be arguing about. Because I think both builds will make similar numbers, with all things being equal. The component in these builds that really changes things, isn't nearly as much of the intake port size, as is the compressor sitting on top of the engine. But, as stated, Payton is very happy with his results, and his goals were met and exceeded. That itself is really all that matters.


http://www.superchevy.com/how-to/061...e/viewall.html

Tom , where you at with your short block ? I have to make sure i beat you to what may be one of the last spined 3.00 pulleys . Going to squeeze it all under the hatch of a 22 so low profile it is , after pulling 1" out of the bottom of the eng hatch.

As soon as you noted it lost in the midrange with the bigger blower that was my first thought that at that level the power needed to turn the blower is what hurt the mid range, from the way I read it seems like that is your assessment as well?

I agree with not arguing which head is better, and is thats really exactly what I didn't want to do, and I agree that they will be very simialar, and the choice from one to the other will solely depend on needs or wants of the end user. I am glad Payton is happy, as thats a good indication that I am going to be happy as well.

Mike - I think there is a misunderstanding or a disconnect in or conversation and if I interpreted anything from you the wrong way I do apologize. There were a few comments there that started to bother me, and they weren't exactly from you, and I think I may have redirected some of it to you in that one post calling you a smartass or condescending. All I know of you is from OSO, so it wasn't very fair for me to comment on any of your abilities or knowledge. Data is an awesome thing to be able to search out, and even though Dyno numbers can be deceiving in certain hands they are good reference points. I just wanted to clear that up, as I think that post may have been a little out of line. Now if you were intending it to be smartass or condescending then I stand behind what I said LMAO

maybe i am wrong but i thought this was a technical forum for conversation about tech.this is why i,and others choose to post here,to help others who are on this forum.you feel that a dyno is not accurate data,then you go on to attempt to school me about dyno,s and how they work.it,s guys like you that make me wonder why i spend time sharing things i have learned but i will continue to do so.in your mind you think i want to compare builds when in fact i would like the knoledge of knowing what the 265 vs 305 head will produce.i was in no way trying to belittle your build.in closing i will say that after you have ran 50 engines on a dyno you might start to have an idea of the DATA that IS gained.YES A DYNO DOES MEASURE THE OUTPUT OF AN ENGINE AND YES IT IS DATA,.good luck with your build.

So in your experience you have never seen a "Happy Dyno" or a Conservative Dyno" ?

yes here on oso things sometime fly out of control in the wintertime.myself,and i believe the others posting on this thread have a love for this kind of stuff and i learn from what others post.facts that get posted can help us all.i,m sure you are a decent guy and i am also sure that you will be happy with the end results from your build.when it is all done,think about posting the results,i,and others just may learn something and after all,that is why we have a technical forum,to share what we have learned.at least that is how i see it.