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Old 08-26-2009, 06:49 PM
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Cheapo BBC 505 tall deck grunt motor

I'm always interested in researching street/strip combinations that are easy on the budget. This is a combo based on the tall deck 427T block. The block deck height of this block is 10.200", 0.400" taller than a regular production 396/427/454 block. The total combined stack measurement of parts I've used here is 10.185", leaving 0.015" nominal piston deck height on a virgin block. I'd check the decks for being square with the centerline of the main bearing bore and if they were, I might leave them alone and use a gasket such as this for a squish of 0.056". You can put this same motor together using a standard production 427 or 454 block, you just use 6.135" rods instead of the 6.535" rods used in this build and forget about the spacer plates.
http://www.summitracing.com/parts/FPP-1071/
Scat cast steel 4.250" crank....
http://www.summitracing.com/parts/SCA-945420/
Eagle 6.535" rods....
http://www.jegs.com/i/Eagle/356/CRS65353D/10002/-1
TRW H112CP+.100 hypereutectic pistons...
http://www.flatlanderracing.com/
Read across the chart for effective static compression ratios with different chamber volumes....

This makes a 505 in a tall deck block for cheap.

Continuing with relatively cheap....
Racing Head Service cast iron heads, 119cc chambers for 10.2:1 static compression ratio....
http://www.summitracing.com/parts/CCA-11301-02/
Published head flow factored by 0.90...
.100 68 56
.200 149 106
.300 221 144
.400 278 176
.500 306 206
.600 324 223
.700 338 239

Use these Moroso rectangular port spacer plates between heads and intake manifold, using Edelbrock #7202 intake gaskets on each side of the plates....
http://www.summitracing.com/parts/MOR-65090/

Edelbrock RPM intake for rectangular ports...
http://www.summitracing.com/parts/EDL-7163/

Or this RPM Air Gap for rectangular ports....
http://www.summitracing.com/parts/EDL-7562/

Or this Weiand Stealth for rectangular ports....
http://www.summitracing.com/parts/WND-8018/

The following DynoSim pulls were made with large-tube, equal-length headers through mufflers and an 850 carb....

More than one professional engine builder has advised that big block Chevies eat flat tappet camshafts, so be aware. I have composed three different pulls, with the only changes being the cam. One hydraulic flat tappet, one hydraulic retro-fit roller tappet and one solid flat tappet combination. I didn't build these to be race motors, but rather low-buck street/strip grunt motor combinations that nose over at 5500. I went through about half a dozen cams on each combination and am publishing the best results here.

I'll run the retro-hydraulic roller motor first. I used 1.8 rockers with it for a new lift of .552"/.572"...
http://www.compcams.com/Cam_Specs/Ca...?csid=445&sb=0
RPM HP TQ
2000 193 508
2500 245 515
3000 311 544
3500 386 579
4000 455 600
4500 508 593
5000 546 573
5500 555 530
6000 490 429
Peak volumetric efficiency 97.6% @5000
Peak BMEP 178.2 @4000

This combo uses a hydraulic flat tappet cam with stock 1.7 rockers...
http://www.compcams.com/Cam_Specs/Ca...?csid=397&sb=0
NOTE: when Comp says "9.5 compression", they don't mean that it specifically needs 9.5 exactly, they mean that it needs AT LEAST 9.5 and could use more.
RPM HP TQ
2000 198 520
2500 251 526
3000 316 554
3500 391 587
4000 460 604
4500 514 600
5000 555 583
5500 558 533
6000 517 453
Peak volumetric efficiency 98.7% @5000
Peak BMEP 180.4 @4000

Now here's one for those of you who don't mind checking valve lash maybe twice a year, although you could probably stretch it to yearly with the technology used today. Back in the day, this used to be a frequent chore, but not so much today. See, the thing is that once you get the lash set properly with the motor hot, you allow it to cool and check where the lash is. Then you can set it cold from then on and encounter no muss or fuss.
http://www.compcams.com/Cam_Specs/Ca...?csid=482&sb=0
Used stock 1.7 rockers....
RPM HP TQ
2000 200 526
2500 255 535
3000 323 566
3500 403 604
4000 478 628
4500 540 630
5000 584 613
5500 600 570
6000 567 496
Peak volumetric efficiency 94.4% @5000
Peak BMEP 188.0 @4500

Last edited by techinspector1; 08-27-2009 at 05:15 AM.
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