Chevy Impala SS Forum banner
41 - 60 of 94 Posts

·
Premium Member
Joined
·
8,673 Posts
WOW KW! That's a serious build :eek:

Can't wait to see the power!
 

·
Premium Member
Joined
·
20,398 Posts
KW, why so much quench?
I wanted quench a tad bit lower......bit I figured that extra .003" ain't gonna kill the build.

KW
 

·
Registered
Joined
·
654 Posts
Discussion Starter · #44 ·
Well.....so far......and in my opinion, Jeff, Tad and others have given you some real good info.

As for me......I'm a couple weeks away from completing an engine build that should've been completed a long, long time ago.

Decked 398ci LTx Block (4.040" bore & 3.875" stroke)
12.3:1 Compression Ratio with .043" Quench
Ported AFR 210 racing heads
1.7 ratio Comp Cams shaft mounted rockers
Solid roller cam; 242* intake duration, 110 LSA, .667" Intake Lift
Super Ram Intake w/Monoblade TB & 60LB injectors
No Freakin' Opti.........LTCC ;)
Stock PCM Tuned by PCMforLess......
I may go to a F.A.S.T. system later after I see what the HP curve looks like.
I plan to rev to about 6800 RPMs.

Engine builder believes 575+ HP/600+ Tq at the crank is likely.

Once complete......engine & chassis dyno figures will be posted.

My only concern is the effect the Super Ram will have on my HP curve. I'm hoping that the rest of the combination can 'break through' the HP & rev limitations of the intake. But hell, that's why we do these things......to see what happens :) .

KW
yes i agree you guys have given me some awesome info and to be honest, this response right here is what i was looking for when i originally asked the question of the hp potential of a small block. now this creates another option because your block is going to be making the exact amount of power that im looking for...at least in the ballpark. im guessing you have about 10-15k in this build.
 

·
Premium Member
Joined
·
3,774 Posts
I wanted quench a tad bit lower......bit I figured that extra .003" ain't gonna kill the build.
KW
err...... .008" over ;)
With a super build like that, might as well spring for Cometic gaskets, in ANY thickness you desire, and get it right!
 

·
Premium Member
Joined
·
20,398 Posts
.......im guessing you have about 10-15k in this build.
I'm pretty sure that I'm in the $10K ballpark. Big ticket items:

I bought the block (an Augostino 396) from a Forum Member. Augostino FUBER'ed the machining of the cylinders and it had a lot of blow-by. Got it for cheap and I'm using the rotating assemble in another build. Had the cylinders rebored/rounded to a .040" over.

I figure the block and machine work to be approximately $1500.

Freshning/machining (for the shaft mounted rockers) the heads (already owned) plus new custom length Valves and Valve Springs about $1600

Shaft Mounted Rockers about $800

Custom length Push Rods about $120

Cam was $350 or so......

Solid Lifters about $330

Custom Pistons W/6" Rods about $1900

Monoblade TB was $300 used

Super Ram intake was $350 off Ebay :)

Electrip WP & Housing about $350

Milodon Oil pump.......not so much

Steph's Oil Pan from King Karl about $350 or so.....

60LB Siemans Fuel Injectors about $450

Tuning from PCMforLess will be $100 (Repeat Customer)

Other miscellaneous expenditures (gaskets & bolt kits) plus assembly labor.

So yeah.......$10K plus a few more is about the ballpark I'm in....and that dosn't including break-in/engine dyno or chassis dyno........(pssst, please don't tell the wife cwm6 )

KW
 

·
Registered
Joined
·
4,506 Posts
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.
 

·
Registered
Joined
·
65 Posts
KW, why so much quench?
err...... .008" over ;)
With a super build like that, might as well spring for Cometic gaskets, in ANY thickness you desire, and get it right!


All things being equal on an engine, what difference would one see with say .039 quench, .035 quench and say what KW has.

HO wmuch of a diff does it REALLY make.


ON my engine it has .039 quench on a zero decked block with felpro 1074's i am now wondering if i should have gotten some cometec .035 gaskets.

It is a budget build though....
 

·
Premium Member
Joined
·
3,198 Posts
All things being equal on an engine, what difference would one see with say .039 quench, .035 quench and say what KW has.

HO wmuch of a diff does it REALLY make.


ON my engine it has .039 quench on a zero decked block with felpro 1074's i am now wondering if i should have gotten some cometec .035 gaskets.

It is a budget build though....

How much difference it makes depends on how much detonation/spark retard due to detonation is acceptable for you. .035 is the recommended number, but .030 I think is the magic number. :)
 

·
Registered
Joined
·
4,532 Posts
err...... .008" over ;)
With a super build like that, might as well spring for Cometic gaskets, in ANY thickness you desire, and get it right!
+1 agreed

my quench is set on kill
I can cruise with the ac on in LA / OC weather and trafic at 16.5:1 AFR 46deg adv on the hwy
freakish MPG!!

also have a buddy who made a hell of a running 355 gen1 SBC
stamped /transfered the TRW PN#s on to the heads
ran single digets on a home brew carb / NA / 355 with a TH350 elco

compression and quench is great combo

wifes elco!
*if the video does not show click the title
Rosie Cranking Compression Video by Rosie - MySpace Video
 

·
Registered
Joined
·
65 Posts
How much difference it makes depends on how much detonation/spark retard due to detonation is acceptable for you. .035 is the recommended number, but .030 I think is the magic number. :)

So more quench equals more chance of detonation correct? Would that little amount of quench be good fornitrous use as well? Would it help cut down on the amount of detonation?
 

·
Premium Member
Joined
·
20,398 Posts
Kevin,

I would keep quench closer to .035" with that kind of compression.......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.
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.

Yes.....the Siemans injectors are high impedance. http://www.bmotorsports.com/shop/product_info.php/products_id/448

And yes.....I did forget about the crank. It was the crank originally in the motor when built by Augostino. I've since bought a Drangonslayer for $500 (from a Forum Member) to go with the original pistons and rods from that engine (for the next build), so I guess that $500 can be applied to this engine build.

So more quench equals more chance of detonation correct?.......
Everything I've read says that the SBC 'likes' .035" to .040" of quench for best power output.

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
 

·
Premium Member
Joined
·
3,198 Posts
[B said:
Less[/b] 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
Less quench does yeild marginally higher compression but reduces detonation by a multiplied factor. In other words, the trade off of higher compression is well worth the added protection against detonation. e.g. High quench area equals high detonation area, and that's a fact.
 

·
Premium Member
Joined
·
8,673 Posts
All this talk of quench has made me thirsty for a cold beer :D

BTW, Karl zero decked my pistons (0.000") with 16cc dished pistons and .039 Fle Pro gaskets. CR is 10.8:1.
 

·
Registered
Joined
·
4,506 Posts
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.
 

·
Premium Member
Joined
·
724 Posts

·
Premium Member
Joined
·
20,398 Posts
Decked 398ci LTx Block (4.040" bore & 3.875" stroke)
12.3:1 Compression Ratio with .043" Quench
Ported AFR 210 racing heads
1.7 ratio Comp Cams shaft mounted rockers
Solid roller cam; 242* intake duration, 110 LSA, .667" Intake Lift
Super Ram Intake w/Monoblade TB & 60LB injectors
No Freakin' Opti.........LTCC ;)
Stock PCM Tuned by PCMforLess......
I may go to a F.A.S.T. system later after I see what the HP curve looks like.
I plan to rev to about 6800 RPMs

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.......
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
 

·
Registered
Joined
·
1,798 Posts
Well.....so far......and in my opinion, Jeff, Tad and others have given you some real good info.

As for me......I'm a couple weeks away from completing an engine build that should've been completed a long, long time ago.

Decked 398ci LTx Block (4.040" bore & 3.875" stroke)
12.3:1 Compression Ratio with .043" Quench
Ported AFR 210 racing heads
1.7 ratio Comp Cams shaft mounted rockers
Solid roller cam; 242* intake duration, 110 LSA, .667" Intake Lift
Super Ram Intake w/Monoblade TB & 60LB injectors
No Freakin' Opti.........LTCC ;)
Stock PCM Tuned by PCMforLess......
I may go to a F.A.S.T. system later after I see what the HP curve looks like.
I plan to rev to about 6800 RPMs.

Engine builder believes 575+ HP/600+ Tq at the crank is likely.

Once complete......engine & chassis dyno figures will be posted.

My only concern is the effect the Super Ram will have on my HP curve. I'm hoping that the rest of the combination can 'break through' the HP & rev limitations of the intake. But hell, that's why we do these things......to see what happens :) .

KW
Come KW you should go for the NA record...that way Mike can get off his azz and hit the 9's...I know Mike wants to just no motivation...give it to him ;)
 
41 - 60 of 94 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top