gtotoocool1

iTrader: (6)

tossing around the idea of entering a motor in the Engine Masters Challenge(assuming they would accept my application).obviously i don't have aspirations of winning or even coming close. goal would be to have an awesome experience and at least have a respectable score for a low buck effort.
anyway,my idea was to put a 4.8 crank into a .030 over iron 6.0 block,with 243 heads.nothing fancy,just good machine work,and a cam spec'd to the required RPM range.
my thinking on this is the 243s should have enough airflow to support 330ci,and the bigger bore to help unshroud the valves.
is my thinking flawed?anybody try something like this?
remember,not trying for an all out effort.i know ported heads/lightweight components would be ideal but not what i'm after.

KCS

iTrader: (20)

I've noticed that the better EMC entries tend to have more "shrouded" valves than what one would expect. One thing the EMC has been great at is debunking conventional wisdom towards how to build high performance engines.

gtotoocool1

iTrader: (6)

yep,ive seen that.i thought the biggest reason was to help control detonation.at least that's the explanation given.
looking at the entries you see a lot of different combos.
or i could just build a 6.0,would probably be cheaper yet.

KCS

iTrader: (20)

I hear rumors of doing separate classes in the future. One for the ballers and one for the budget guys, so you never know. I like that idea since it seems like the same 10 builders win every year, and this may encourage more of the average joe's to participate since we won't be up against the likes of BES, Kaase, and SAM.

gtotoocool1

iTrader: (6)

actually they have that this year.that's what made me think about trying to enter.
a few years ago a guy built a 305 pulled from his back yard.used a basic rebuild kit and honed the cylinders with a block of wood and sandpaper,lol..
made just under 400hp!

ZexGX

iTrader: (28)

I think two turbos would help.

KCS

iTrader: (20)

Thats scary, lol.

LS1Adam84

iTrader: (21)

Yeah this setup would be great with two turbos as well, but the more important issue is going to be an oil pump to support the high rpms as well the valve train, I threw this motor into a program at school (DynoSim5) and it worked out well with boost BMEP was in the 5-600 PSI range and MPS was around 4800 fps. This was on twin t88 turbos and about 14 lbs of boost. The motor reved to like ~9k rpms.

I would love to see how it works out for you, I want to do this as well.

KCS

iTrader: (20)

The EMC only pulls to 6700RPM and turbos are prohibited. It's mostly about overall horsepower and torque per cubic inch, and I'm not so sure a destroked LQ4 is going to do the trick. At least, there really doesn't seem to be a real advantage to it. Similar ideas have been tried already.

gtotoocool1

iTrader: (6)

yeah,no turbos in the EMC..
if you look at the top 10 finishers for 2010,3 of them had big bore/short stroke combos..
the 7th place finish of the Power Shop Racing SBC had a whopping 307ci,with a 4.030 bore/3.0 stroke.
338ft.lbs at 2500rpm,with a peak of 417ft.lbs at 4700rpm is pretty good for that small of displacement..
it's not that i think there is an advantage to a short stroke/big bore combo.it's about feeding enough air to support the engine your building.IMO,it's cheaper to make HP per CI on a smaller motor.i have a set of 243s laying around in my garage. untouched they will flow enough air to support 330 cubes.
plus the biggest advantage is i can get the rest of the parts for dirt cheap,lol.

Grr

iTrader: (2)

I would think you would have better luck since its rpm limited with a 4.8/5.3 stroker myself, with a ton of compression

KCS

iTrader: (20)

I agree for the most part, but as far as the competiton goes, I think the more important question to ask is will the heads feed the engine where you want it to? The 243/799 castings supported the 364ci LS2 in an RPM range similar to the EMC RPM range, and heavily worked over, have supported 427ci engines to 9600RPM. Sure they'll support a 330ci engine, but at what RPM? I would be worried that the power would come in too late in the RPM range to score points in the EMC.

gtotoocool1

iTrader: (6)

i see your point.
but for the most part,the intake and cam will determine the rpm range the motor will make power.
at 210cc intake port volume with the stock valves i don't see a problem making power in the 2500-6500 range as long as it's cammed properly,and of course the right intake is used.(hell,i will probably just use the truck intake!)i would bet you the smaller cube EMC motors ran bigger intake ports then the 243s.
keep in mind the 799/243s are used stock on the later 5.3 truck motors.
like i said,i don't expect to win or even come close,just a respectable finish with the parts i have on hand.

gtotoocool1

iTrader: (6)

the street class is limited to 11.5:1 CR.and i would use every bit of it.of course that is for this years challenge,next year might be different..

Old SStroker

I would use a 3.90 bore (LS1) and the 4.8 crank for about 313 inches. That is not far from the dimensions of the LS engined Daytona Prototypes (DP). Since block weight is no penalty for a dyno "mule", start with a recycled 4.8 truck engine. The iron block has the same bore as the 5.3 and can be safely bored to 3.90. You can also us some very nice shelf Mahle pistons, or relatively inexpensive slightly specials. Upgraded rod bolts in stock 4.8 rods will be more than sufficient. At the relatively slow acceleration rate used in the EMC, lightweight rotating/reciprocating parts are not a good bang for the buck.

Heads will be the most important issue by far. Ported 243s with stock size valves were used on the DP engines. The latest ones used the FAST LSXRT intake (146602). The 90mm truck intake is a close second and might even be better for the 6500 max speed and it is a ton cheaper. DP engines used the fugly truck intake until the FAST was approved and they went to 7100.

Done correctly, the engine described above could be a contender for the EMC Street Division class win. You would need the correctly ported heads, the correct valvetrain (which could be HR, very lightweight and affordable), and absolutely the correct tuner for the EFI engine. All of those things/people exist, and they are not involved in the EMC as far as I know.

Second point: if a 4.00+ bore was considered (330 or so cubes), you could do better with L92 heads. I suggest that about 98-99% of the folks who read that would either strongly disagree or laugh. Talking with the other 1-2% might prove instructive.

FWIW, it's probably way too late to apply for the 2011 EMC...unless they didn't get much response in the Street Division. I haven't checked recently.

My highly-opinionated $.02


Jon

gtotoocool1

iTrader: (6)

yep,too late for this year.all applications are filled,and the deadline for mailing was the 15th.this would be for next year.
thanks for the advise Jon,i appreciate it.now that you mention it,i was tossing the idea around of using L92s,and i have a small cam that might actually work with those heads on a small cube motor.216/224 112+3 lsa.although probably a little small and i think it would peak a little too early.(maybe if i install it at 112+0?)
i have some parts laying around and not a lot of money.just thinking if i do this,making the most of what i have on hand.and the tuner would be me,so not a lot of help there!lol
but now you got me thinking!

Old SStroker

That was the plan!

Jon

FWIW, a 313 that had a fat torque curve and made 530 hp @6500 would be in the running.

gtotoocool1

iTrader: (6)

Don't think that would happen with my budget,lol.I was hoping for around 450 or so with a fat TQ curve.

gtotoocool1

iTrader: (6)

the more i think about this,the more i like your idea of using the 4.8 block bored to 3.90.since i already have the 243 heads and truck intake,it would be a little cheaper then the L92 combo.
i agree with you about the lightweight rotating assembly,not worth it for the minimal gains.if i was going all out and looking for every last point,sure. i will definately use the truck intake,i've seen a couple drag racers as well use that a few years ago with good results.
as far as the heads,i would just go with a GOOD VJ and bowl blend.that alone should get me to around 280cfm with the stock valves.plenty enough to feed the roughly 313 cubes and attain my power goals.
the key is to get the right cam/intake/exhaust combo(obviously).
the heads,pistons,headers and cam is where i'll budget most of the money,along with the necessary machining.
would be cool to use the GMPP ASA cam,love the thought of using off the shelf parts.but probably not ideal for the smaller cubes.although if i can get my hands on a ASA cam for cheap i might test it just to see what it would do.no matter what i'll have an expert spec me a cam.definately worth the minimal expense.
anybody have a 4.8 truck motor laying around they want to get rid of?lol.

1904gto

iTrader: (4)

i remember i thouhgt of a smilar idea awhile ago and asked the ppl on yellowbullet.
i always say alot of sbc destroked 400s making more power and rpm than 383s
came to the same conclusion..