EMC 289

General engine tech -- Drag Racing to Circle Track

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Steve.k
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Re: EMC 289

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BILL-C wrote: Thu Oct 10, 2019 11:19 pm
hoffman900 wrote: Thu Oct 10, 2019 10:59 am Bill-C,

How does this engine compare to the road race engines you build with these heads?
The FIA european spec 289's that we build will typically have either production 289 head castings or the better C6FE heads, depending on the chassis engine is going into. We run 11.25 CR compared to EMC max of 10.5. FIA mandates correct vintage heads and blocks, flat tappet cam and lifters,stock type rockers-- NO ROLLERS ALLOWED!The only intakes allowed are the stock Shelby's,performer rpm,or webbers. Obviously, this makes it tougher to make reliable power. Typical output is 380 tq and 450 hp with production passenger car heads and 20+ more with the GT-40 C6FE heads. In USA 289 engines we are allowed to use the better 351W and C6FE heads and high compression ratio.500+ hp common. Some sanctioning bodies like SVRA allow aftermarket iron heads and roller valvetrains.580+ hp achieved with proper budget B production 289's .Performer RPM intake still required.T/A 310 cid versions 600+ with dual plane, 620+ with Vic Jr. Because of the way the rules are written, we never build any 289's with C5AE production heads and roller valvetrains. If we did, power in the 500 neighborhood is possible. Peak hp would occur at a higher rpm than scored by EMC though.
Bill I'm very impressed with the hp of these small engines. With the weight of one of these power plants and in a 2+2 chassis or falcon these cars would be very tough to beat. Not to mention cobra or sunbeam tiger. Wow.
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Re: EMC 289

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Steve.k wrote: Sun Oct 13, 2019 9:45 pmBill I'm very impressed with the hp of these small engines. With the weight of one of these power plants and in a 2+2 chassis or falcon these cars would be very tough to beat. Not to mention cobra or sunbeam tiger. Wow.
Yes, Mummert did an unbelievable effort on the old iron SBF. From a guy who built these iron SBFs for Sunbeam Tigers back in the day, that's why there's an Early Iron class. Today, we don't take on an aluminum LS. That's really tough to beat.
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Re: EMC 289

Post by GARY C »

Mummert wrote: Sun Oct 13, 2019 1:36 pm Years back, we played with perfomers rpm, which I believe are the same as E-street but with better parts, and vic jrs,. I liked the performer rpms pre 2003' before they changed the casting, on smaller engines.
If there is something to be learned from this whole project, what it takes to make 450 hp on a pump gas 289 as far as cylinder heads go is more based on air speed than based on big flow numbers.
Any chance you can share anything here?
This comment comes up all the time and there are countless threads on this subject but few details in regards to technical info of what one should be trying to achieve in this area.
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THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
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Re: EMC 289

Post by Steve.k »

Well I mostly work on cleveland and bbf so im used to healthy flow numbers. When we did this 306 with estreet heads I thought looking at ports it will be a miracle to get power outta this thing. I was pleasantly surprised.
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Re: EMC 289

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GARY C wrote: Mon Oct 14, 2019 3:44 am
Mummert wrote: Sun Oct 13, 2019 1:36 pm Years back, we played with perfomers rpm, which I believe are the same as E-street but with better parts, and vic jrs,. I liked the performer rpms pre 2003' before they changed the casting, on smaller engines.
If there is something to be learned from this whole project, what it takes to make 450 hp on a pump gas 289 as far as cylinder heads go is more based on air speed than based on big flow numbers.
Any chance you can share anything here?
This comment comes up all the time and there are countless threads on this subject but few details in regards to technical info of what one should be trying to achieve in this area.
Its relative to a curtain area/cu.in. relationship. On one end of the extreme you have big bore short stroke 4 valve type engine and on the other end you have a Big Block type engine.

Big blocks can achieve some valve area, but because diameter expands on one plane, the early curtain area suffers ( or exposure area as I refer to it). The throat will usually become the choke point in the port. The entrance to the port and ssr area will be large and funnel it way down to the throat. Because the valve is essentially at the choke point the cam profile will become a huge player in the ports velocity profile.

Modern 4 valve engines are quite different, and seeing how these engines are still evolving at the oem level, they can be tougher to get a handle on.
Many modern powersport engines have bore to stroke ratios in the 65% range, and have valves that are 38-42% of the bore. So imagine a 450Ci v-8 with a 4.8" bore and a 3.12" stroke and a pair of 2" intake valves. Makes the math easy, area is Pi x2 6.28" and circumfrence is Pi x4 12.56". Compare that to a typical 454 with a 2.25" valve, area 3.97" and circumfrence is 7.06"
The point of all this is that the valve area and curtain areas so great that attmepting to port or camshaft them in a typical Big Block method will lead to disaster. Port velocities and valve timing events will be so far out of tram it wont know wether is coming or going.

Modern 4 valve heads are built to achieve greater average port velocity, choke points are placed closer to the port opening. Trying to use the valve diameters as some meaning of port efficiency has just about no meaning. Its even common at times to place strategic shrouds or tumble dams too fool the engine into thinking the valves arent as big as they really are. Unshrouding these areas and adding some extra cam can really screw some things up if your not careful. This is hard for v-8 guys to wrap their head around.

Massive curtain area engines have many advantages, but the door swings both ways, they are easier to screw up, by over camming or over porting.

The 289 is none of these engines, its not an under valved big block and its not an over valved sportbike engine either. Hopefully using two different extremes one can see when you start playing with a very over square 2 valve engine, that the curtain area can exceed what the engine might need, and it may not be necessary to achieve the peak flow potential of the valve if the choke point is properly sized and your average port velocity is up.
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Re: EMC 289

Post by GARY C »

Thanks for the response.
Please Note!
THE ABOVE POST IN NO WAY REFLECTS THE VIEWS OF SPEED TALK OR IT'S MEMBERS AND SHOULD BE VIEWED AS ENTERTAINMENT ONLY...Thanks, The Management!
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