MDchanic

I would just like to interject [why? WHY??] that it seems to me, to the best of my recollection, that the key point that was left unsaid, but which I believe was implied, is that there is a direct correlation between fuel consumption and horsepower provided that the air/fuel ratio is being held tightly within the optimal range (which is easier with a closed-loop FI system than with a carb).

IF the engine layouts are comparable in terms of parasitic losses before the crank (ring friction, bearing friction, oil viscosity resistance, oil pump resistance, etc.), and

IF the fuel is all being completely burned (proper A/F ratio) inside the combustion chambers,

THEN the amount of energy feeding the system (fuel consumed) should correlate directly with the amount of energy leaving the system (crank horsepower).

Confounding variables would be designs that tolerate very different oil viscosities, designs with very different internal friction profiles (Wankel? NikaSil?), and bad air/fuel ratios in one engine or the other.

- Eric

marzgtp1

Im looking to do a stock rebuild on my olds 455 I was wondering what it would cost I was looking to spen about 2500. Does that sound right?

VinMichael

Where does it say all engines? I think he was referring to two particular engines, a Ford and a Chevrolet, with similar EFI systems, which deliver and measure the amount the of fuel being released in to engine. The engine making more power, with similar EFI and fuel measurement systems, required more fuel. Both were measured on the same scale, but differed in power and fuel consumption.

captjim

Did you read my original post with prices outlined? You are not going to do a quality rebuild for $2500, that was the whole point of this thread.

captjim

I think I can pretty much agree with that, well stated. I am not sure how induction/cylinder head design would affect "Efficiency", bit I suppose it would be a very minor variance.
One thing to perhaps add is camshaft, seems like that could have an effect, too.

coppercutlass

I beg to differ on price. A good street strip build for what you priced out is good. I rebuilt a 350 for around 2500 that ran high 13's I ran it for 2 years put 10k miles on it and it still running in my dad's 77 pontiac. No smoke no knocks it is as quiet as a stock engine.

marzgtp1

Coppercutlass, do you know of a good machine shop thats not
to pricey here in il I just want a stock rebuild its still running just leaks oil here and there and a small knock its oit of timing might be why its making that noise

captjim

Please do a DETAILED list of prices and machine work. Show me where you shave $1500 off of my list. If you included used parts and free machine work, I am going to aggravated with you. Also, re-ringing is NOT a rebuild.

A rebuild brings the engine back to OE specs. Machine the block, crank, rods, and heads, replace pistons, rings, bearings, timing chain, oil pump, cam, etc. Just because it ran good for 10,000 miles does not make it a rebuilt engine.

380 Racer

^^x2^^

MDchanic

Head / manifold / carb design affects efficiency by providing resistance to the induction and expulsion of gasses.
This does two things:

One, an engine pulling or pushing gasses against restrictions uses energy in order to pull in or push out the gasses. Energy that is used to move the gasses through the engine is lost and cannot be used to turn the crank. While the piston traveling down on its power stroke is providing energy to the system, the other ones that are not on their power strokes are at best dead weight, and at worst are resisting movement (and absorbing energy) through their actions as they pull in or push out gasses. This situation creates more and more resistance (and losses) an the engine turns faster (and makes more power).
This sort of inefficiency actually burns more fuel (uses up energy), and so can introduce an inaccuracy into the fuel consumption vs horsepower comparison.

Two, an engine pulling or pushing gasses against resistance (but especially pulling) reaches a "terminal point" where no matter how hard it sucks, it can get no more gas through a given restriction (sort of a cavitation scenario - instead of pulling more gas, the suction just creates a vacuum, without any more gas being brought in), so the engine can put out no more power, even if it turns faster. The effect is similar to valve float: it reaches a certain output (or speed) and can go no higher.
This sort of inefficiency burns no more fuel, as no more fuel is being brought in, and so fits within the fuel consumption vs horsepower comparison.

Depending on design, an engine may or may not, under the right conditions, be able to conform with one or both of the above scenarios, but this is how head and tract design can affect efficiency.

As far as the cam, "old-style" non-variable camshafts achieve maximum efficiency only within a narrow RPM and throttle band, where the speed of the moving column of gasses in the intake and exhaust tracts matches the demand of the cylinder. Under all other conditions, efficiency is reduced, as is MPG. As with most things in life, this is most clearly illustrated with an extreme example, which is the "full-race" lumpy-idle camshaft, which doesn't even close the valves until the piston is halfway along the cylinder, and which causes exhaust gasses to be pushed into the intake, and unburned mixture to be pushed out into the exhaust pipes at idle, though it creates a "perfect storm" of flow in and out at, let's say, 6,000 RPM. A cam like this under less-than-race condition (ie: partial throttle, midrange RPMs) will be a pig, blowing unburned gas out the pipes and wasting a phenomenal amount of potential power.

- Eric

captjim

Hey Copper, still waiting for your reply. I made a detailed post outlining costs, you tell me I'm way high on the price. You challenge my statement, tell me where it is incorrect. You have been posting here all day.

coppercutlass

ok give me a second.

coppercutlass

ok the shortblock cost me 750 i bought it from a local with a towing cam already installed. The heads where freshened up by rrp for 380. the 100 for the used edelbrock intake and 260 for the new 600 cfm carb . then 165 for the hei . the headers cost me 120 from a local racer . add about 200 for little odd's and ends that is 1975 my friend. I look for deals to have fun for half the price and i know the right people . here it is in my car


he it is in my dad's car.



now you can get off my back .

captjim

Your last post is a friggin joke. I am not getting "off your basck" as long as you call my statements innaccurrate then follow it up with nonsense. That crap you just posted IN NO WAY resembles a rebuiklt engine.

Here is the problem; you continuously spout "my $2500 rebuild engine that runs 13s" and the average guy thinks that you can get a properly rebuilt engine for that, which you can't. So guys ask about budgets, you tell them, "sure, you canm get it done for $2500" then they end up disappointed or grossly over budget. The purpose of this thread was to shop realistic prices to build a 325 HP 355 using NEW parts.

coppercutlass

It was proper it does not smoke it does not make noises it ran 13.86 and it is now in my dad's car after i put 10k on it . My last one died budgets have limits and i pushed that one. Rebuilding that term rebuilding means to refurbish or re use to some extent so me re using what is still good is not wrong you need to use a dictionary more often . Your definition of proper is diffrent than other's That little 2500 dollar 350 still runs with no issues it has for the last 5 years whats wrong with that. Try spell check too

coppercutlass

If you where using all new parts why didnt you also use brand new aluminum heads., to some guys that might sound proper . get where im coming from now. Again if you can quote me where i said you where innaccurate do it. I said beg to differ. as in disagree not that you where wrong.

captjim

Once again, not accurate. Be careful calling me names son, I will bury you. Spell check? Really? Every post you make has words mis-spelled. Can you read? try this,
http://www.timscbx.com/Adobe%20folder/eng_rebuild.pdf
The defintion (not MY definition, industry standards) is to replace all wear parts and machine the other parts. Machine the block, crank, rods (since new ones are not available). When done the engine will be to factory specs on clearances with new wear parts. That is not my interpretation.
What you did are upgrades or repairs. Not even close to a "rebuild".

captjim

Once again, you are wrong. You machine castings and replace wear parts. I had the heads pressure checked and resurfaced, new valves, new guides, new seals. Those are the industry standards for cylinder head work on a rebuilt engine.

coppercutlass

Yes and for some rebuilds you can re use pistons, rods, even cams if the wear pattern is correct. Im sure you know as i know the industry standards are not always followed. Sometimes a good call can be made if someone decides to say hey the piston skirts have minimal wear they can be re used. Not all egines get 165k and sludged up you know. I did body work for 7 years and let me tell you there could be a text book telling you how to straighten a frame but not all accidents are the same so having to do diffrent methods than those of books sometimes is called for.

coppercutlass

Yeah but you said a rebuild w/ NEW parts you can buy new heads instead of using 40 year old castings.

coppercutlass

Just like when rocket racing freshened those heads up john made the call. He said the heads look like great low milage heads just freshen them up . That was a good call that saved me money that is where someone who is truly experienced can say what you can and cant re use. That 73 350 was rebuilt/freshened up it was in good shape didnt need anything major.

captjim

Is "diffrent" a word?? Better try Spell check

The last SMW 350 was made 36 years ago. The chances of finding one where the pistons and cylinder walls are in spec it very small. If "industry standards" and not followed, it is not a complete rebuild. Same with rods. If the parts are in spec, fine, but if they are then chances are the engine is still in the vehicle and running good. You keep making things up to suit your statements.

coppercutlass

Look i didnt make anything up . When i rebuilt my last 350 i measured the piston skirts, rod and mains and cyl. walls . Everything was withing factory low and high limits just not the strongest parts to use for what i did. There is a reason why companies like lkq sell salvaged engines to shops., because not everyone can afford a new engine . Just like them i cant afford alot of expensive stuff so i make do with what i got and take my chances . When my 350 gave up i admitted it i said how i built it and how long it lasted and what it did. To some that might appeal to them becasue they might not have 5 k now but in a year they can save that and keep their car on the road. Which is the same reason i have a 307 in my car now. I spent an extra 200 to keep it on the road. because i know i could build the engine i wanted in a year. I just like to give people other options im honest about my failures and when im wrong i admit it . My low 13 sec 350 had parts fail. My high 13 sec 350 is still strong and running. I gave you the proof i put up a vid and posted the $ what more do you want. You know you gotta crawl before you walk. Well im willing to make a few mistakes before i do it right why? Becasue if you have nothing but success then when you fail you will not know why . Making mistakes is a chance to learn. I spent my money on things i could re use and spent close to nothing on my shortblock because i knew it was not going to last very long . I had every intention to build a better shortblock and i am now.

coppercutlass

The industry standard is the industry standard. I would love to meet some machinist as see if they all follow the "standard". Everyone has their own way of doing things. Just like some guys swear by restrictors but btr say's they aren't needed.

coppercutlass

I work in a machine shop machining ring gear and pinons for heavy duty machines and i can tell you., you can cut the same gear twice and have to use diffrent settings to get the right finish and size. Just like every engine is diffrent everyone has a diffrent budget mind set and goals. You just need to respect that . I respect the fact that you built a great engine . I build a strong little runner that is still running today with not alot of money . You are just so hung up on following the standard and doing it by the book . Let me tell you soemthing., guys have built 6 k engines that died on initial start up i buil my junk ran it beat the crap out of it and it finally gave up a year later. I like to do things diffrent and taking risk's even if it means spending a little extra. You can say i built a junk engine that lived a year but it beats the guy's who have had their engine die within 300 mils or start up so i did something right to make that junk live that long. There is always two way to look at things. The glass can be half full or half empty .

captjim

So then stop saying you rebuilt your engine for $2500. say that you did a re-ring freshen up with some used parts. .0025 is about max for cast pistons. Hard to imagine that after all those miles and a clean-up hone it is still in spec.

coppercutlass

yep still within spec i have good sources for parts. Most guys will generalize re ring with a rebuild like i do.

captjim

Not the guys I know.

cutlassefi

Dude, be real careful telling people to use spell check, you're one of the worst, as I've pointed out above. When you first started posting here I distinctly remember calling you out on your horribly constructed posts. Everything ran together and you had really bad spelling and punctuation.

When you post what you feel people can do for $2500.00, be specific right away. Don't mislead people. There's enough bad info on the net, don't add to it.

coppercutlass

I know im not perfect and type too fast for my own good. Im not saying my info is correct im just putting out there what i have done and my success and failure if it does is told. I am specific on my builds my., 2500 dollar engine still lives and my 3500 dollar build bit it .

cutlassefi

Wait 2 seconds and then type. You tend to spew at the mouth and have some of the worst grammer period. That's pretty rich calling someone else out on that. It's almost as bad as "my dad can beat up your dad". I was waiting for that to come next.

Post facts not bullshyt. You'll get much more civil responses, I promise.

coppercutlass

I never posted bull. I post stuff based on my experiences .Didn't really care about his grammar . I posted my facts no bull. I posted the prices i posted the vids yet again repeating my self If you guy's want to come down and see the damn thing run come on by that's the next step. How did i post bull . people just need to get of their damn high horse and admit there are other ways to do things and it does not make them wrong.

cutlassefi

Maybe so, but you have a habit of not posting all the info right away.

And you still need lessons in grammer and writing so don't go there. Quite frankly I think in that respect imo you owe Captjim an apology, because you are consistantly one of the worst.

Done.

coppercutlass

Nope. Not gonna happen . You guys sit there try to make it work for your benifit on calling people out so what if i didnt fill in all the info., if some asked i would gladly put it up. I always do. There is no point in posting the detail unless some cares enough to ask. Im not gonna waste my time and the o.p.'s thread space. Im just tired of people giving me crap all the time for stupid crap. certain people need to come around and admit not everyone had/has the money to do it right down to a tee . I atleast give an alternative to just no it cant be done. Im tired of it. People dont see two sides they see one i respect peoples opinions but like to give them another option or road that might work with their budget. In aother post he say's no one makes good cast units i give him a company and he craps all over it and bases it on price when price was never spoken about. It was just about how he said no one makes a 14cc or 7 cc dished cast piston. REALLY. Thats about as bad as me calling his grammar.

marzgtp1

Coppercutlass,
I understand your point.

olds 307 and 403

A re ring should only cost $500, mine did. Is it right? No, my car has been slower than it should be. Somehow it has been reliable, engine wise. I rejetted the carb and got my timing under control with a $400 Mallory ignition. Just a start but I need to start somewhere. DoubleV did a proper engine build by pros who build Olds engines. His compression numbers are awful, just like his luck. You can get bit either way, difference is he may have some coverage on the work to be fixed. Remember Mark and Jim build engines for a living, they do it properly or they get bit.

coppercutlass

I did mine simple and they ran great. I must be that special person that gets lucky. Either that or I use common sense and take my time even when I built a junk bottom end use used parts and I managed to run 13.3's . Even when builders cover themselves it's bound to happen ask mark. It's happened to lots of guys who spent big coin on engines. You can do a proper re ring and bearing deal and not loose power. Re ring with cam, and bearings, and good timing set and new freeze plugs will run more than 500 depending on what you want. I don't buy rebuild kits or re ring kits I pick my parts carefully.

olds 307 and 403

I guess it depends on the definition of re ring. I did mine because of little $$$. I slapped my truck's 350 together even cheaper. Uses and leaks oil, annoying. Still equal to a 5.3/4L65E combo with the same gearing but worse mileage.

ah64pilot

You guys ought to keep this civil. There's more than one way to skin a cat...and everyone is going to have a different opinion of what a rebuilt engine is...despite what the "industry standard" is. Whether you do it all or do the bottom end or whatever, the main goal is to keep the thing running.

Both of you have shown you can do that, and while I err to Jim's figure of $4,000...I would be lying if I said I hadn't ever built a $2000 engine before. Your experience, and your budget will be the determining factor for what you "shortcut".

And in the end, the money you spend is in no way a guarantee that there wasn't a mistake made along the way. Even high end engines fail on the dyno

J-(Chicago)

I must agree with Jim on this one. In fact, he is on the LOW side for HALFWAY decent parts.
Can I slap together a bbo that runs high 12's for $1200......yes. Is it a complete rebuild?......heck no.

Jim's post emphasizes ZERO corners cut on a rebuild start to finish. Everything back into its proper tolerance. There ARE some corners that can be cut.....but they are usually out of your control.

If your block has no wear, hi comp pistons, perfect crank journals, and already had roundness in everything that needs it, you can save a few bucks, but that's about it.