what to look for in a "GOOD" engine combo

[grumpyvette]

I got asked , "what makes a GOOD vs A poor engine combo?"
and without getting into specific combos , too deeply,
lets look at that question

the first few things I look for in most magazine engine builds, I read about is the use of fairly easy to locate parts, from several known manufacturer's , having a good reputation ,for supplying quality components, and a combo of components that has a semi- reasonable cost to power ratio, and one the average guy can afford to build with easily duplicated parts.
keep in mind theres a HUGE difference in the component selection process and basic goals when building a race engine, where peak power is your main concern, and rebuilds and parts replacement are EXPECTED on a regular basis, vs a high performance engine designed for street/strip use and at least occasional transportation use, where long term durability and rock solid dependability are your main concerns, and you expect to see 100K plus mileage out of any combo, you build
youll also want a parts list from a source that will be around for years, and have access to replacement parts.
Parts that won,t cost a great deal more, than similar components, from other sources, and parts that I can purchase and replace at a later date if necessary.
I also read carefully to see it the articles obviously designed to push or sell particular components , and compare the results to personal experience because , its common for those magazine engine builds to leave out or flat out lie about results at times
I also want to know that the combo will be durable over the long term, and I generally look for a combo that won,t require excessive or expensive custom machine work.A combo that will run on available pump octane fuel,and if the guys building the engine don,t concern themselves with building a stable valve train at the intended rpm range and building very effective lubrication system, and efficient exhaust scavenging , and effective cooling,the combos likely to lack durability!
youll generally find the better engine combos reach peak power about 1500rpm-2000rpm higher than peak torque, but have that peak power curve slightly below critical stress levels (generally under 4200fpm in a chevy V8) and maintain the fairly flat torque curve well over the useable rpm range thus gearing and tire size matching the intended use is also critical

I generally look at the combo , and calculate the peak and average piston speed as its a good indication of stress levels , as anything I'd suggest building should be durable over the long term, if you constantly need to replace components due to wear or parts failure, its not a well thought thru combo.
I want any American V8 I build or recommend duplicating to make or exceed at least 1.2 horse power per cubic inch of displacement, without power adders.
one of the first things youll want to look at is the basic engine block and rotating assembly strength, a bit of research , in the strengths and flaws of each engine family design,the extent of aftermarket parts support, may provide you with info that can save you a great deal of wasted effort
Any good combo should have a torque curve that will be useful in the applications intended rpm range.
On most muscle cars that will place the torque curve peak about 1000rpm-1500rpm lower than the power peak and the peak power a bit below 4200FPM in piston speed
a good many times I see guys build engines that might make very good power , but not in an rpm range that is really useful for their application.
it does little good to build an engine that makes killer power levels at 6500 plus rpms and then stick it in a car with 3.07:1 rear gears and an automatic transmission that shifts at 5500rpm, thus preventing the engine from operating at anywhere near its most efficient rpm band, most of the time!

I get lots of guys who have a 307-350-or 383 in their current car that have developed a taste for performance but want something a bit better that the mildly modified engine they currently have,and once you get serious you quickly find that the stock components won,t hold up, or allow you to produce the power levels you really want.
this almost always leads to the purchase of better quality aftermarket components and the frequent use of local machine shops and a rapid education in the costs involved in engine building, followed quickly by drive train and suspension upgrades.
you know I have similar discussions with the guys around here who want to upgrade from their current 383 sbc engines all the time and I usually break out a catalog and a legal pad and start listing a dream sheet with the required components the costs listed, the likely machine work, and by the time we get very far into it it usually becomes rather obvious that we will be some place in the $8K-$12K or higher dollar range by the time we get into a decent dart block,a decent quality forged rotating assembly,then heads from, afr, or brodix ,or profiler heads, and a decent induction system,rockers, etc.dependent of course on what you can use if anything from the current 383 sbc build.
at that point I generally point out that for the cost they can reasonably expect to have built a 505-650 hp engine.
I then point out that in most cases the combo is unlikely to be extremely street drive friendly, and its most likely going to require rear gears and average operational rpm ranges that will not be ideal for long term street use durability.
at that point I generally point out that a big block engine with significantly more displacement can be built for similar cash outlay , that can produce significantly better power per dollar spent.
think about what your doing before diving in and spending cash!
if a 383 sbc makes 1.2 hp-1.4 per cubic inch of displacement you can expect 460 hp-536hp
if a 540bbc makes 1.2 hp-1.4 per cubic inch of displacement you can expect 648 hp-756hp

HERES A FEW DECENT MAGAZINE BUILDS
SBC
http://www.airflowresearch.com/articles ... 5/A-P1.htm
http://www.airflowresearch.com/articles ... 9/A-P1.htm
http://www.airflowresearch.com/articles ... 8/A-P1.htm
viewtopic.php?f=69&t=4378

BBC
http://www.airflowresearch.com/articles ... /A-P1.html
http://www.airflowresearch.com/articles ... /A-P1.html
http://www.airflowresearch.com/articles ... /A-P1.html
http://www.airflowresearch.com/articles ... 3/A-P1.htm
http://www.airflowresearch.com/articles ... 6/A-P1.htm


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[87vette81big]

I like the idea of having multiple engines and cars Grumpy.
Build each to meet different needs & requirements.
One has to be a Secret weapon racing machine.
Don't have to follow others leads that way.
Open to Prototype engine builds no one else has or dares to build.
I don't follow.
Do what want.
High octane 110 motor Octane gasoline non blended ran straight.
Static cranking compression ratios & camshafts chosen to deliver 310psi pressure on 2-3rd crank revolution.

[87vette81big]

Makes for a Beast on the street unleashed in my experience.

[grumpyvette]

one factor in building a performance car, or potential mistake!, Ive seen repeated over and over during my life, and watching my friends build and swap cars over the years, and while enjoying or cussing at times about this rather addictive at times hobby,
or obsession many of us have ,of trying to build or at least own an impressively fast car, is that many guys seem to assume that the only option they have is to start the process,with the car they use for transportation,and while being limited to the original engine, the car they own came with.
when you first start out most guys seem to be unable, to step back mentally and picture clearly what they really want to build and they just seem to concentrate on swapping out a few components.
now there's little doubt you can increase a cars stock level of performance with minor upgrades to those components like swapping to a more performance oriented intake manifold or more aggressive cam, tuned headers,or swapping to a low restriction exhaust or similar parts, but at some point they eventually realize the basic engine compression ratio, displacement and more major components like the block, rotating assembly and cylinder heads are a big limitation, and the more astute thinkers usually realize that there may be a much more effective route to building power or a totally different engine family that can potentially provide a great deal more brute torque or hose power than the stock engine ever can.
example
lets say you start out with a rather typical mid 60s-1980s camaro, nova, dodge dart, mustang or an older muscle car like a chevelle, or GTO.
At first its got rather impressive performance and once you throw a couple hundred or thousand dollars into the engine compartment you arrive at a point where you might have knocked a second or too off the cars original E.T. and added several miles per hour to its 1/4 mile trap speeds.
but at some point you'll look back and if you bothered to keep all the parts costs listed and total them up you-ll usually find you could have built or bought a far more impressive car, with what you've spent at that point.
what Im trying to point out here is that a few days of research and planing can go a long way to reducing mistakes and wasted money, in your quest to build an impressive car. and you might find that building a separate spare performance engine or in many cases a dedicated weekend toy over a longer time frame will result in a much more impressive car that you might eventually build if limited to swapping out parts on that original 307 sbc, or low compression,350 sbc that came in the car.
I don,t know too many guys that stuck with this hobby that would even think about building the car they first started out with in this hobby and even fewer that would select the same engine they started with.
, yes I know your funds are limited and you might not have the skills to do much at first , but if you join several performance car clubs and make the necessary contact youll find you can gain the skills and make better decisions, as to what you want to build and how youll go about it!

A FEW VIDEOS TO HELP YOUR ASSEMBLY

http://www.youtube.com/watch?v=eSxjI6BxgpI

http://www.youtube.com/watch?v=PXFT4ShDryk

http://www.youtube.com/watch?v=PbbPXuwDYfE

http://www.youtube.com/watch?v=rXp1vVtsp7s

http://www.youtube.com/watch?v=xQFlaDhWsck

http://www.youtube.com/watch?v=r1PO26ZqUEs

http://www.youtube.com/watch?v=sQhNIiPyTB4

http://www.youtube.com/watch?v=iuj9nfQ-LRY

http://www.youtube.com/watch?v=HrtQVhcTPFc

http://www.youtube.com/watch?v=ypQwgm1H2NU

http://www.youtube.com/watch?v=-VwsbEg7Z4I

http://www.youtube.com/watch?v=bcMuttJ9RFc

http://www.youtube.com/watch?v=1LcYEZwOIQQ

[grumpyvette]

reading a few dozen, links and sub links can go a long way to help you figure out what you want to accomplish, and how you might go about doing it efficiently at the lowest cost.
DECIDE what you REALLY WANT and build it, driving a car with a enhanced 383 sbc engine because its what you could afford immediately, when you really REALLY! want a 540 bbc in the car eventually gets VERY DEPRESSING
make the contacts in the hobby, join a few clubs and help others on their projects it always results in your gaining skills and a better understanding of how components fit and function.
yes I know 90% of the people reading this will read at most one or two links, but youll save months of effort and thousands of dollars if you read all the links and sub-links...simply because youll have a better grasp on what your doing and what to avoid doing.
most guys will find buying a decent spare performance engine, part by part and assembling it, having machine work done and researching what they need, slowly over time , and building with exactly the components they want and once its complete spending a weekend swapping engines has huge advantages, one is limited down time and the second is having the option to swap back to the know working dependable stock engine should anything happen to the weekend toys power plant.
now you can swap in some components you might need well before the actual engine upgrade like a bigger radiator, better brakes , etc. but the idea here is not to be in a position where your primary daily transportation's screwed up, and your both broke financially from parts purchases and have to get the car up and running. Its far better to pick a long weekend or a weeks vacation to do the engine swap, then test drive it a few days and not have huge expensive surprises, this route is far better than tearing the engine down, ordering parts or waiting on a machine shop to complete work while your cars not drivable, it also allows you to keep your pride and joy engine and sell the car with its original engine once your tired of the car rather than being forced to take a huge financial hit buy including an engine that the new owner surely won,t pay you full value on when you sell the car, after your done playing with it!

What I like is, building cost effective,easily duplicate-able engines, from off the shelf components if what I need is available, if not I have zero problem fabricating some components or modifying whats available if required,engines that use mostly built from well matched correctly fitted components. I like having total predictable control on a valve train components and long term durability, with low maintenance and in most cases large displacement high compression engine combos
I prefer to keep the piston speeds under 4300feet per minute , and Id prefer to keep the compression as high as I can , simply because its generally going to make for a more responsive combo with higher torque in the useable rpm range.
now in most cases thats engines of 400 cubic inches or larger displacement, and when I can 11:1 or higher compression, so 7000rpm is about where Im comfortable limiting valve train speeds, and I have zero issues building bigger displacement combos that might never see 6500rpm.
given the choice Id gladly give up that last extra 2%-5% of potential horse power in exchange for an added 20%-to-50% greater engine life expectancy, which is in many cases a choice you ARE forced too make
.

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[87vette81big]

Being a Pontiac, Corvette, and Oldsmobile, Ford, & Mopar Fan I have found only 2 clubs that like me & accept me Grumpy.
The Chi town 5.0 Renegade Ford Mustang Racers.
They ask me how to fix. Go faster.
Your Club here.

I have owned the TA since 1994.
Filling the 18 gallon tank with 110 octane s a pleasure.
Does not bother me.
Have done it many times.

I read many of your links.o
Give me ultumate Race Fast.
Thanks.

BR
.,

[grumpyvette]

I got asked why I seem to have a marked preference for building big block engines VS the far more common small block,
think of it this way, your average street driven performance engine designed to run pump octane fuel will produce about 1.1-1.2 hp and about 1.2 ft lbs of torque per cubic inch of displacement, if you select a reasonable list of components.
yeah! we know you can exceed that power, but on average thats a reasonable expectation.

so lets say you build a 383 SBC vs a 496 BBC

lets assume 1.2 as a factor for both, ignoring the fact the BBC has far better flowing heads and stronger parts

383 x 1.2= 459 hp/tq
496 x 1.2 =595 hp/tq
but you say what about the BBC weight? well its usually about 100 lbs heavier, so lets look at that factor

your average corvette or camaro probably weights 3300 lbs MINIMUM

if we divide 3300 lbs by 459 hp we get 7.19 lbs per hp with that 383

if we divide 3400 lbs by 595 hp we get 5.71 lbs per hp with that 496 BBC

if we assume 20% less rear wheel hp, the 496 BBC makes 476hp and easily runs mid to low 11 second times if properly set up and tuned

http://www.race-cars.net/calculators/et_calculator.html


if we assume 20% less rear wheel hp, the 383 makes 367hp and easily runs mid to low 12 second times if properly set up and tuned


you don,t need to get exotic for decent street performance, theres dozens of potential choices, but Id certainly think seriously about a big block with 480 plus cubic inches
and yes as usual reading the links and sub links will provide you with a ton of additional related info


http://www.chevrolet.com/performance/crate-engines/big-block-502-ho.html

http://www.vortecproperformance.com/engine_combinations.html

http://www.ohiocrank.com/enginespage1.html

http://www.herbertcams.com/dhp-482-new-custom-big-block-stroker-engine-600-hp/

http://www.proformanceunlimited.com/spe ... roker.html

http://forum.grumpysperformance.com/viewtopic.php?f=69&t=5123

http://forum.grumpysperformance.com/viewtopic.php?f=69&t=8383

http://www.westcoastengines.com/383-stroker/

yes its true that you can generally build a SBC engine for less money,
but once your done
WILL YOU BE HAPPY WATCHING THE TAIL LIGHTS OF THE GUYS THAT WENT THE BIG BLOCK ROUTE?
yes theres plenty of fast SBC cars , but its POWER TO WEIGHT that mostly determines your potential, and as long as the cars are fairly heavy the BBC has advantages