Inliners International Forums General Discussion Hi Performance OK think I have been swayed. . .250 or 292 for my setup?

Ok I have always had my problems about not making up my mind. But think I am getting really close to what I want to do with this Nova. I currently have a 194ci which I think, which much feedback hehehe, that I need to drop as it's not going to get me where I want performance wise.

I thought about the 383ci V8. However I weighted that in for quite some time and think I'd rather be different. The inline six-cylinder power manual from Leo Santucci has helped in alot of ways.


Now my question. What would be best for my application? I want to turn this 4dr sedan to a street/strip car. I want to run 13s and below int he 1/4 mile. With the car weighing in around 2570lbs fully loaded, I don't think it would be much trouble. But then again, even after reading all of this stuff, I still dont' have the feeling of the inline.

I understand the 292 is a torque monster for the most part. 170ish hp however 275tq


And the 250 isn't really that far behind.


So what would be better? Where are some places where I can find said engines and parts? I've searched over GM Goodwrench but haven't had any luck finding a 292 inline 6 from them. Am I looking in the wrong place?


And now the main part. With the 250ci. . .what would be the best power I could get running NA. And same with the 292. . what's the best I could get out of it running NA.

Now reverse this and add Boost (N20 or Turbo) I read in the back of the manual that @ 30lbs of boost, out of a 250 the lo is 581hp and the hi is 860hp whereas the 292 is lo - 679 and hi - 1005hp.

How accurate are those numbers on a forged block??


And if I go nitrous based instead. . .how big of a shot would a forged 250 take and a forged 292 would take?


btw I have searched the boards for these kind of answers but haven't had much luck =)

Thanks

your drag Q's can most likely be answer by Larry/Twisted 6. as he runs 13's i beleive with a 250.
good luck!

.desperado.
.sam.

The 250 is more of a bolt-in motor whereas the 292 has the different mount location on the passenger side and I believe you will have trouble with the 292 pan in your Nova. But it is hard to beat cubic inch for power. Do some more reading in Leo's book and I would think that you can make the 250 work for you if you are going to run nitrous and some kind of injection, lump ports and a few other mods. Good luck and keep us posted on what you decide to do...

If I am understanding things correctly, the 250 will bolt right in without any modifications in the 1st gen novas?? That being the case, the 250 probably would be better suited for sake of ease.


I've read on the front of this website under racing of a few people hitting anywhere from high 12s to low 14s running NA out of a 250. Which now leads me to a few questions

Where can I get forged internal parts for an inline? I haven't had much luck finding these parts.

Would it be wise to remove, port n polish my 194ci head and use on the 250 to increase it's compression? And about how would it affect the compression? Stock it's 8.5:1 right? Would it net me close to a 10:1 compression?

I understand the intake manifolds and carb parts. If I use the head from the 194, I would have to replace the intake anyway as it's part of the head on the 250 right?

So parts list
194 ported head
42-4501WH - intake manifold from Clifford with 4bbl plate
DEMON 525 Jr. Carb or Holley 390-450 4bbl.
Set of Clifford Headers
Cam with either 270/214 or 280/226 lope 110
Chrome moly pushrods


As for remainder of exhaust, how do many people here handle this? Do you install a y or x-pipe and dual cat-back. Or a Y-pipe to a single cat-back. Or dual straights? I believe it would need some back-pressure but not exactly sure how to set this up.


Thanks

Raben,

Do a search on crankshafts on this forum, lots of good information on pros and cons of different year crankshafts, knife edging, etc.

Adding backpressure to an exhaust system is never a goal, but sizing the elements of the entire system to maintain flow sometimes appears to have that result. I don't know what you mean by cat-back; your 63 would never have had a catalytic converter. An x-crossover would be the most efficient, but won't be as effective on a straight six as on a V-8 as the six already has evenly spaced firing in each manifold and the firing order of the V-8 precludes this. For the street, just run whatever sounds good to you and run open headers without restriction on the strip.

Baldy

Raben

All the information in this topic seems really good for us. But I have noted that has no one answer about where you can get performance parts.
I don´t know where you live, but if you are in the US, you can find some of these parts in PES(Performance Engine Service) and in the Sissel´s site: www.sissellsautomotive.com
About the pistons, my opinion to you is to search in Ebay. If you will choose a 250, you can search for Chevy 307 V8 pistons too. Sometimes its easier to find some!

Good luck in your project!

Thanks guys. Yea I'm stateside

Bald. . .yea I'm still thinking modern era on exhaust hehehe. I was curious how to run the exhaust. I understand when I had the LS1 in my Trans AM, I had to have some sort of back pressure. I was unsure how to handle this on an inline 6 or if it's needed at all.

So I really don't need a x or y pipe after the headers? Just run them straight to the rear if I wanted a dual exit? Was thinking flowmaster or magnaflow mufflers to the exhaust.


Seiscanecos. . .thanks for that piece of information. The only place I found parts was cliffords and stovebolt ofcourse, but are primarly simple bolt-on parts. Internals, etc I found PAW however only cast pistons. Could not find anything forged.

I will look into PES and Sissel's sites and see if I can find the other products from them. I do plan to choose the 250. I want something pretty simple to install and if I can achieve the same goals with the 250 as I would with a 292, then I'd go this route. Seems with all the changes that would be needed for the 292 to be installed would nearly amount to the same work needed for a small block V8 which is where I want to stay away from.


So the Chevy 307 V8 pistons are the same in size as the 250??

NAPA has a limited number of performance parts for the 250. That's where are bought my cam, and 307 pistons. They also have oversize valves, high wind valve springs, oversize valve seats, manifolds, headers, et.

Something that intrigues me as I progress on my own 250 is this: The stock horsepower rating is 155 HP. According to some figures we ran on a desktop dyno you can add 40-50 horses by bumping the compression, bigger exhaust valves, better carb, headers or other free flowing exhaust, performance cam, et. Mostly bolt on and easy internals. Now here's the rub; 50 horses is a 33% increase! That's a difference you can feel! That's what I'm shooting for. I've decided not to go the lump port route this time around. I think I'm getting enough increase that I'll be pretty happy. (Most old worn out high milage 250's are putting less than 100 horses on the ground. Something to think about.)

Boo Radley

Yea if I buy any used engine off someone I plan to do a full engine overhaul because of that. I'm sure any engine 30 to 40 years of age isn't going to preform up to par

That's good that NAPA carry some of those parts. I've sent a couple of emails off to sissells. . I saw some interesting stuff on their website, so hopefully they can give me some feedback on a race preped inliner


Thanks everyone!!

That's right. Guys talk about needing to do all this radical stuff to their street engine, and some guys (Twistedsix for example) do race these 250's, but think about this. My worn out 250 was only putting about 115 horses to the fly wheel. I could go down the freeway 70 mph passing cars in my 4000 lb truck, and with my 4.11 gears it was amazingly quick off the line. Now imagine 200 hp at the fly wheel and a 3:42 positrac. There are several rice burners and a few V8's around here that are about to get a rude awakening! Since I'm running dual pipes into a pair of cherry bombs, make that a VERY rude awakeing!

Boo Radley

Raben, not all 250's had the integral head, mostly the ones from the early 80's. This short block is OK to use but you don't want anything to do ith the integral head. Redo the head off of your 194 (bigger valves, heavier springs, etc) and put it on the 250. It will raise your compression.

Hitting the Low 14s to HIGH 13s is do able But Not 100% street friendly Due to the Gears. But everyone Has their Own Ideas of what is street able Or not. As for Lower ETs 68 camaro Here Runs 11.80 @ better then 110mph. NO Baby Bottles No Turbos NO Blower.

Now as for PES The Only Intake That I know of That he sells IS NOT a STREET intake It is all Out Roundy Round Or DRAG Only. I will be posting Some intakes Later Next week Closer to next weekend Of Intakes That are now Being sold Here in the USA From Our friends in South Brazil
I have from them single 4bl, Dual Weber Downdraft IDF type 40-44-48 carbs Triple Weber down draft IDF type carbs Valve covers side covers. What I will do is Make a HP goodies link/Page. I will not have time to do THIS this weekend But I hope to have it done Later in the week If Not By Next Weekend for sure..

Now back to the Motor issue The 194 head can bring your compression up to 10-1 useing the 307 pistons Or any Flat top. A true flat top No Valve releaf can Net you a little more. But If you plan to install a 1.94 on the intake It Will need to be unshrouded. But the Stock Valves Or even a 1.8 Can FLOW Very Well with a Lump port.& and with The Port work & 3-4 angle valve job and the Right cam & intake system You can have One VERY Hot Street & 1/4 pounder. One thing You never said ,So i must ask is this a STD or a AT tranny your planing.?
So i hope this helps so far. }[oooooo]

It's an automatic. I have a shop that can race prep rebuild the powerglide. . .or I have two other optiosn, a Th350 or a 4l60E tranny. I want to use a 3500 stall converter with the setup as well.

Track Wise the power glide would be ok But street Hum it may not be to happy Or at least the Motor Won't Sound to happy.(it will sound as if it will pop out the Hood ) So I'm sure it would be Much happier on the street with either one of the Other Trannies. And to get below the 13s The Cam Choice and Stall won't be enough I don't think.
NOW as to going to the Turbo side YES this could be more do able and Much more street Friendly PerSay. and Wouldn't Need the Deep Gears You could stay down in the Low 3:00 or lower 2:80??-2:90 gear sets and Small cam Profiles. Hope this helps }[oooooo]

Thanks twisted. That's probably the route I will go. Get a TH350 tranny with a 3000 or 3500 stall converter, 12 bolt rear with maybe a 3.73 gearing. And go the turbo or nitrous route Turbo would be better ideal I think for what I want.

I just need to find some examples of other people setups so I know what to look for.

Thanks again.

Your Welcome . The 3:73 gearing will be to much for the turbo on the track. But ?? maybe ok if your keeping the Boost on the Low side 7psi or maybe Less???? With the Turbo You do Not Need a HIGH RPM motor hope this helps }[oooooo]