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There is no way you can bore a stock block to 4.125". Even a 4.060" bore requires sonic testing. $15k may not be enough to have a 409+ ci deep stroker to rev to > 7000 rpms reliably.

For 600+ hp a big cube LSx engine is a much better value.
 

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Kevin,

That's a very interesting engine build.

Like Mike said, I would keep quench closer to .035" with that kind of compression. What does the dynamic compression comes out to? Mine was 8.9:1 with 12:1 static compression - with a 238/250/110 LSA SR cam.

I do not think you need the monoblade because SuperRam has a lot of plenum volume. It might be difficult to tune it at idle/very low throttle especially considering the injector size (they are still high impedance, right?)

P.S. I think you forgot to add the 3.875" crank to your list of high $$$ items.
 

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Dmitri,

My dynamic CR should fall right in the 10.3:1 range; a bit high.....thus the need for a very conservative street tune. My race tune will be for 105 Octane fuel. I'm not to concerned about detonation.

...

Less quench will result in more compression and will (depending on quench) result in detonation regardless as to how much timing gets pulled. Going below .030" quench opens the door for engine/heads moving parts to meet in a rude manner.

KW
There is no way the 10.3 number is correct. Are you using advertised IVC number to calculate it? 9.3 is probably more like it. The problem with too much DCR is the engine is more likely to detonate at part throttle so the timing must be very conservative. It can make the engine less responsive on the street.

Reducing compression by increasing head gasket height (or deck height) is counter productive.
 

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Got with my engine builder yesterday........this is what we have going:

Head Volume CC:.... 56cc
Flat-top Pistons:...... 5cc valve reliefs
Deck Clearance:...... .004"
Gasket Thickness:... .030"
Quench:............... .034"
Cylinder Bore:........ 4.040"
Gasket Bore:.......... 4.110"
Stroke:................ 3.875"
Rod Length:............... 6"
ABDC @ 0.050 Lift....... 64*
Plus 15 Degrees

SCR 12.91:1
DCR 10.36:1

Using the calculator at the below link:

http://www.kb-silvolite.com/calc.php?action=comp

If anyone has a "better" calculator.......push it my way :) !

KW
I like this calculator:

http://www.not2fast.com/turbo/compression/compression.shtml

I got 13:1 static compression and 9.1:1 dynamic compression. It is slightly on the high side but can certainly be tuned for.

The assumption, however, is that the seat-to-seat IVC value equals tot he .050" lift IVC + 15 degrees. It may not be true with solid roller cams as they are more aggressive. So the dynamic compression would end up higher due to a smaller IVC angle.
 

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Are 18* heads more expensive to top of the line 23* heads?
When buying new, an 18* intake cost right about as much as a high end 23* intake. Same for the rest of the parts in an engine.
You would also need different pistons (most of the time), custom headers, offset shaft-mount rockers and lifters....
 

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Following the same logic I can't understand why so many 383's are build when a 409 cost the same. The only difference is notching the blocks for the rods to clear and I have never hit water yet with an LT iron block. Really I do know the answer to that question and it's because a 3.75 crank will bolt in without notches, I don't know why notching blocks scares people. I have never built a 383 to date, every thing that comes from me has been a 409 because it was cheap, almost free, extra torque and HP over the 383's.
A 383 can be built with off-the-shelf parts without compromising compression ratio, etc. It has a higher reliability than a 408 due to a slower piston speed, more static piston height as well as reduced cylinder side load.
 

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Way off topic and I have to stop but good sharing on the block issues including LS engines. I still think too many people think they can bolt an LS engine in their car and make big power they see in the mags they read. I can already smell the antifreeze coming out of the heads!!
I have an LS1 in my Mazda with lightly ported heads and a small cam (220* intake duration) and it makes as much power at the wheels a 383 LT4 stroker with LE3 heads and a solid roller cam.

Granted, the drivetrain losses are not the same between an RX7 and a Caprice. But considering the huge cost difference between the engines, LS1 is a much better deal. Now a 6.2L LSx with L92/LS3 heads is a whole different ballgame. I do not see any reason for building an 18* headed gen-1/2 SBC unless you are racing in a specific class.
 

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Sooo after I blow the doors off these lsx turbo implals on the forum with my LT1, then what???
Numerous people on the forum tried to build a turboed LT1 impala. Most of them never finished it or had issues and sold the car. Good luck with that.
 
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