Inliners International Forums General Discussion Hi Performance Lookjing for 300 Hp What can I do?

Firstly I am not sure where to post this,secondly I have Chevy 250 from a 72 Chevelle, I am looking to Get about three hundred horsepower what can I do to see these numbers. I have some headers, offy intake with a quadrajet on it,HEI. What else would I need? Specific parts would be great. I Don't want to much of a fuel eco decrease if possible so I don't want a crazy cam. Would the stock block accept nitrous? I have read that somebody on here makes turbo manifold should that be my route?

Since you are concerned with fuel economy somewhat, a turbo can help offset this and still provide very adequate HP and driveability. These blocks are very strong, and both nitrous and turbos have been used on them with great success. Tlowe is dyno testing with a turbo on the 250 dyno project going on right now, and 300 HP has already been achieved N/A, so higher HP is expected with the turbo setup. Just stay tuned in to see the results. You can PM him for more specifics if you need to.

I'm hoping for a similar number, although I am aiming for 250-260 horsepower and 300-310 pound feet of torque, our of my 250.

The first thing I would recommend (and most people here) is to get a copy of Leo Santucci's Inline 6 power manual. I've read and re-read mine and it's a fantastic resource.

You should also read T. Lowe's dyno thread too.

My plan to get there is as follows:

250 block bored .60 over for 258 Cubic Inches
Knife edged crank
292 oil pan
Prepped stock rods
Forged pistons to increase compression ratio
Head work with bolt in lump ports (head milled?)
1.94 intake valves 1.60 Exhaust valves
Harland Sharp roller rockers
Cam (not sure about duration yet)
HEI ignition
Dual Webers with Clifford intake manifold
Headers

I'm sure there are details I am missing.

I do know that the stock block can accept nitrous and turbocharging is also an option. Was your engine rebuilt or did you just bolt on these parts?

Short&wide, it looks like your off to a good start for your project. There are several cams that will put you right on the money for your goal. Let us know which one you select to finish off your engine with.

Well I already have A copy Of Santucci's book. But while the engine has not been rebuild it has relatively low miles and I took it apart and everything looked good. That I why I put it in in the first place.It replaced my 65 Chevelles stock 194 even though it only had 61,000 miles on it. I am trying to avoid a total rebuild though -I know build one of these engines for cost won't work-But I had a perfectly good 4 bolt V8 I could a thrown in-I am just a bit more loyal to these Engines. I want bolt on parts though so the car isn't laid up for a while-It's my daily driver I take to work and school. But what about this Nitrous -The stock block will take it? How Much is too much? I found a Quadrajet NOS setup I was considering but I didn't think she would be so happy with it being bone stock and all.

If your engine has cast pistons in it, they will give up long before the block will if you are planning to run nitrous.

uhhm are they cast? I really don't know. Is that what came stock in these engines? What would I need to do if I were to up the compression.

Yes, the stock pistons would be cast. You probably need to consider your end result for what you are wanting out of your engine, and base your build-up around that. If you are considering nitrous and a relatively stout engine, then forged pistons should probably be placed into your budget. Cast pistons are fine for daily drivers and can even endure short bursts of nitrous in low HP levels, like dry shot kits, but they are still just cast, and not really intended or designed for high RPM or bigger HP nitrous kits or high turbo boost.

Thanks! I've been researching this for some time now and accumulating parts a bit at a time for both the engine and truck.

I am in too much of a toss up to know what to do. There are so many parts.
I think I need to go over exactly what parts too do. I don't want to overshoot my goals. I want to know what parts go with what to get the most torque I can at 300 hp. I set 300 as the goal to have an actual stopping point before I start work on my 69 Deville. But being a bit shy of it isn't so bad. What type of gains do I get from what? And what cam should I buy that would not have so much lash. My major concern really is to be extremely street-able.

Head work should be at the top of the list of things to do. Adding 1.94" valves and lumps will go a long way in getting you to your goal. The 292 dyno testing that Tlowe did, easily exceeded 300 ft.lbs. of torque with only 8.8:1 compression, and you can as well. There weren't really any combos that were tested that you would say were "unstreetable".

A turbo set-up or supercharger would be extremly street-able.

Look @ that thrown together turbo set-up Tlowe did on the dyno.


MBHD

Yeah, it just depends on how much you want to spend, and how much work you want to do. 300 HP is going to be relatively easy whether you go N/A or Forced Induction, just choose which method suits you the best.

Cheap is nice. I make minimum wage,but every dime I don't spend on gas to get to school I save for my car. How do I get to Tlowes Dyno result everybody keeps talking about?

You can use the search function and type in "292 Dyno",or just PM him if you want to.

I have been looking at a number of cams from Crane and Comp-what would be best for me? Do fuel eco cams provide extra power? All of the other ones seem to give of some valve lash. I want to run smooth. Am I asking to much are all of the things I want possible together?

Everyone has their own definition of "streetable", and what they want in terms of driveability and drive characeristics for their engines and vehicles. What one person thinks is streetable, might not suit the needs of another person. So its hard to tell you specifically what you will like or need, not knowing what really suits your real personal taste and needs. There still might even be some experimentaion needed on your part to find the happy medium between parts for power and smooth driving like you mentioned. When you are talking about doubling the stock HP of an engine, at some point you might possibly cross the line beyond what you thought you would end up with to get there.

I think you need to send him money to get the dyno results.

I guess its a secret,, for now,unless you have some money to give him.

Otherwise,I can point you in the right direction to build a "on the cheap" turbo set-up.
It's not hard or complicated.

MBHD

I didn't have to send him any money to find out....

I didn't have to send him any money to find out.... [/quote]

If that's the case,,, why dosnt everyone get these dyno sessions sent to them.
Why have a confedential agreement sent to guys that have this info that have been donating money for Tom to do this testing.

It's not free.

Isn't that because you are writing & going to get all this dyno time published for him?
Tom told me only guys that have given money for the testing has been sent this info,excluding you I guess?
MBHD

From Tom's very first post mentioning the 292 Dyno test, he spelled out that 1 of 3 easy requirements would put a person in the loop for the data from these test:

1)Financial Compensation
2)Parts Contribution
3)Knowledge Contribution

Surely, you could have done one of those 3 things, 75 other people did. He made it easy so everyone could be involved that wanted too.

Tom has also freely given this info to many newcomers to the forum that came in after the fact. Thats why many of their questions are answered by myself or others to PM him, or he has Pm'd them himself to answer their questions. 100% of all the members of this forum and club were given the same opportunity to participate in this group project and no one was excluded from the opportunity to do so. Only those that made a decision not to be a part of this group project, excluded themselves from it.

Hank,
I think you do not have a clue how much:
Work
Time
Money
went into these tests.

For the 250 so far I have signed 2 checks, with a total of about 3000.00. And that does not pay for all the parts, ie pistons, bearings ect.
Yet you expect to have full access to all information gleamed from these tests? No real help was provided by you. I try to help bring people into the club. This happens by getting them interested in the inline engines.

To me, with you not being a present member of Inliners International,, you are a free loafer. To me new members should be given a grace period of 6 months to a year and then either join or not be able to post. Luckily, Titen does not feel the same way. And maybe thats ok too.
I understand people can go thru bad times, been there and done that.

So the tests that were done by me included my own blood , sweat and tears. And no the info is not going to handed out like candy at a parade. It is certainly shared to many people and will continue to be.

Tom

No they shouldn't be given 6 months to a year.To free Load info!!
So Titen is NOT the only one who feels that way and Neither am I.
Secondly I never seen Glen Slef,Mike kirby, Jack somers,Clifford,
Or anyone else In the Inliners World come to the clubs Forum.To ask/beg for money to help do the Testing/s they wanted to.

So why did you USE the clubs Board in that manner?And don't say I just wanted to Help.To try and toot your own horn would be a better answer I think.

[I can point you in the right direction to build a "on the cheap" turbo set-up.
It's not hard or complicated.

MBHD [/quote]

Hank............why don't you post up the right direction for one of those "on the cheap" and easy turbo set-ups? and maybe even a twin turbo set-up so I can retain at least some of my 'split-six' sound?

Joe

This forum has been extremely beneficial, and continues to be, for me. However, when our members leave the subject matter and hit other members over the head with a verbal 2 x 4, this one with a nail on its end, it should be seen for what it is, a lack of self restraint. This lack of control began on this forum ever since TLowe began selling lumps on e-bay, competing with Larry/Twisted6. Larry, it's about time you cooled your jets.

Your right George. And the reason it is, is because of members like Tlowe who have stepped into and taken a leadership role and rose to the task of answering all these questions that no one else seemed willing to step in and do. This is what clubs are all about, everyone uniting together and pooling resources to gain knowledge. Many other forums routinely have members asking other members for money to do groups buy-in with automotive parts companies all the time, this is no different. I think Tom has done an excellent job in compiling so many different combinations and testing so many different variables that have always been asked, but no one could give answers to. Tom has also spent a lot of his own money for both of these projects, and much of his own Blood, Sweat and Tears. We need more guys like Tom that are willing to roll up their sleeves and Git'er Done attitude.

Oh Boy look what I started. I don't mean to cause' no fuss.

Overbite
you didn't start anything and didn't cause any fuss.I was just making a point on this whole dollor thing,& member ship.And just a few took it out of text.

And George as to what Tom does on Ebay is up to him and that's the very least of my worries.He is not the first to do these type of dyno tests.And i am sure he wouldn't/won't be the last.I
know people who have done just the same on chassi and engine dynos. Both are very good for a base line for performance. But when both are done in a controled environment (temp, humidity etc) That is just what you have a Very good base line.
Real World street or Track tuneing is where & when you find/get all that you can.That is my opion only because i have spent countless hrs On flow benchs and Chassi dynos. The reason I picked/Used a chassi dyno Is I wanted REAR wheel HP & torque numbers.
So just like all other opinions Each has their own.Right, wrong or indifferent.We all have our very own.thats why we are all different.And we build or do things that works best for us.

I have given input & parts ideas for Tlowe to use,since he did not go in the direction I mentioned I guess I did not qualify LOL.

I do not need his results of any of his testing as I have done most of this type of testing in a real car & in the streets & race tracks.I've done this testing over 20 years ago, & others have done it before I have.

Most input or guessing I have done off the top of my head is pretty much correct.
The Offy is a better street driven manifold for a mild engine,w/low stall converter.

As far as Tlowe saying the peak torque is way better w/the Clifford,because it showed a peak torque of 1.something ft lbs more?
I would call that a wash,or pretty much dead even IMO.

What these engine dyno tests do not show is how bad the Clifford manifold causes the carb to meter air/fuel poorly off idle & part throttle acceleration.

All my tests were done on various 250 combos.
I cannot speak for how they would run w/a smaller engine like a 230 or a 194, but I would take a wild guess that the results would be more apparent on smaller engines than a 250,,meaning it would be even more pathetic trying to accelerate w/those smaller engines w/a Clifford intake.

None of the Tlowes dyno tests are done @ partial throttle openings or 800 RPM & up, as to where my testing on a real car shows actual part throttle acceleration,idle to peak RPM etc.

The problem that most car mags shows when dyno testing an engine,is just like Tlowes testing,no part throttle testing,off idle testing,just WOT testing & who drives around @ WOT all the time?
These tests do not reflect how the engines react under normal driving conditions that you or me driving on the street or track.
Again IMO.

MBHD

I think you need to look @ what you are saying.
I never exspected nor wanted full access for your tests. Dont flatter yourself.
All the tests shows is W.O.T. I do not think most guys here drive @ W.O.T. all 100% of the time.

I do know what it takes to do engine builds & dyno testing.
I just think your more overwhelmed & shocked yourself,so again watch what your saying.

Two checks ,,hmmm,,,& how much of it was your money?

I chose not to give much info or help because when or if I would,you would just take the credit yourself like you thought of it.
As far as me being a member,,,,how many times do you need to mention that,I am getting a little tired of that & sure other people here are also.

If the forum needs contributions to stay a float I would gladly donate if need be,but not to a money demanding person like you.
I am glad you are not in charge of this forum as others are also glad.

Also as far as being a free loafer,get over yourself ,Mr free advertising on the BB here. Get real!
I am not gaining any financially by advertising here or offering services for a fee like you are.

I offer free real driving advise from actual testing I have personally done w/a good friend.

To me personnally you should not be here & should just stay on your ownsite giving bogus single sided advise,just IMO.

How about you do some real testing on some cars & actually drive them with different cams,manifolds,carbs,different compression ratios as I have done.

An engine dyno is just part of the picture.

Thanks

MBHD

Hank............why don't you post up the right direction for one of those "on the cheap" and easy turbo set-ups? and maybe even a twin turbo set-up so I can retain at least some of my 'split-six' sound?

Joe [/quote]
Joe,

I will get back to you after these cheap shots @ me blow over.

Thanks

MBHD

Hi

I´m also going to put turbo and intercooler my 292 chevy, is it ok to use original cast pistons or do I need forged ones? And most important question, where can I find forged pistons to l6 292

Thanks

Tzei (Finland)

you can use them But it would NOT be in your best interest. For they will not handle much boost Nore will they handle it as long as a forged set would. Many companys can make what you need inlines of a forged piston. Ross,aris to name a few.

Oh Tom Just for your info MBHD is a Paid member and here is His member ship #4665

Yes, I know tha it is not best way to go use original type cast pistons but if I use 6-7 PSI max with intercooler is it possile? Custom made forged pistons are not cheap I think.

A cast piston, if run cool with conservative spark, will handle some mild boost, but... you only get to be wrong ONCE. Then you buy new pistons anyway.

This is more like it. Thank you, Larry, for sticking to the subject. You've probably forgotten more than I'll ever know about high performance inline engines. I value the information you offer. Thanks again.

Obviously, which dyno to use is a matter of choice, and if your existing data is based on chassis it's an advantage to continue.
However: in my limited experience, a chassis dyno requires careful control of factors that are absent (and therefore neutral) on an engine dyno. These have a considerable effect on power delivery to the wheels, and are generally harmless and may be ignored in back-to-back tests of the same chassis with motor mods, but (IMO) not as closely monitored or regulated as would be needed to make effective test comparisons between different chassis. It can be done, but requires more work and record keeping.
These include such seemingly minor factors as driveshaft/U-joint angle, type and size of differential (Ford 9" has far more power loss than GM, 7.5" ring gear vs. 9-3/4"), viscosity of hypoid lube and transmission fluid, torque converter slip, ATF temperature, tire diameter and compound, tire pressure, etc.
How the engine gets air with the hood closed also varies somewhat between chassis based on hood clearance, underhood air temperature, fan discharge pattern, etc.

Panic has a point. I have used only chassis dyno's, mainly because I'm too lazy to pull an engine just to have to put it back in. Things as minor as a tire pressure adjustment or how tightly you pull the straps down can affect your readings from run to run. However, mostly I use the dyno to check the AFR's and make sure the ignition system is up to snuff. In my opinion good recordkeeping with lots of runs at the track looking at mph are the best indicator of hp.

Is there any suitable forged pistons what can I use like some SBC pistons. I cannot find 292 forged pistons from any manufacture or any catalog. Is custom made pistons only way to go?