Thread: Just scored a 427 tall deck want to stroke it out

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Just traded my 454 block for a 427t out of a dump truck. Motor has just been rebuilt from gm with 4.310 bore. I want to put a 4.5= stroke in it with 6.7 rods. I heard its possible to do, any one have any tips? Im thinking maybe small rod journals for less block clearancing, or is that even necissary?
Any help would be greatley appreciated!!!

Here's a 505 budget build that I was playing with a while back. I didn't check with Pat McCarthy yet to see if he would put his blessing on it. Maybe he'll let us know if it would work as presented or not....

Cheapo BBC 505 tall deck grunt motor

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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/trwchevyspecial.html
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....
Bare heads....
http://www.summitracing.com/parts/RHS-11301/
Assembled heads, max valve lift 0.600"....
http://www.summitracing.com/parts/RHS-11301-02/
Assembled heads, max valve lift 0.750"....
http://www.summitracing.com/parts/RHS-11301-03/
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

I had a little time this evening, so I put this motor back in the DynoSim and tried two dozen different solid roller cams in it. Here's the winner....
http://www.compcams.com/Cam_Specs/Ca...?csid=511&sb=0
Used 1.7 rockers. Everything the same as the above Sims....
RPM HP TQ
2000 195 513
2500 250 525
3000 319 559
3500 404 607
4000 487 639
4500 560 654
5000 615 646
5500 643 614
6000 643 563
6500 593 479
Peak volumetric efficiency 96.9 @5000
Peak BMEP 195.1 @4500

Thanks Tech Ya your rite thats definetly a lot cheaper and pretty much bolt on to with no clearancing issues like with the 4 1/2 or 4 3/8 stroke.

I left out some info also. I have solid roller comp cam with .622 lift 110 lobe and 238/246 duration at .050. My heads are iron gm heads ported and polished 106cc with stainless manley valves oval port. I was wanting to go with the 4.5 stroke for more torque along with my oval port heads and longer rods for less wear on the cylinders and longer life.

Originally Posted by yblow

Thanks Tech Ya your rite thats definetly a lot cheaper and pretty much bolt on to with no clearancing issues like with the 4 1/2 or 4 3/8 stroke.

I left out some info also. I have solid roller comp cam with .622 lift 110 lobe and 238/246 duration at .050. My heads are iron gm heads ported and polished 106cc with stainless manley valves oval port. I was wanting to go with the 4.5 stroke for more torque along with my oval port heads and longer rods for less wear on the cylinders and longer life.

What's the casting number on the heads? Any bowl work? "Ported and polished" is such a hackneyed phrase and means nothing to me because any jackleg with a Dumore could have cut into 'em and screwed 'em up. Have you had the heads flowed on a bench?

For what its worth---I had a 10.2 truck block at 4.280 bore, 400 long rods(alum) with some 454 deck ht pistons, stock 4.0 in stroke crank, The C exhaust port heads, bowl work, minor clean up of ports, NO cutting of the heads at all, .760 lift mech rollar cam--ran 8.002 at 169.99 in the monza in my avatar---

[QUOTE=jerry clayton;381140] bowl work, minor clean up of ports, NO cutting of the heads at allQUOTE]

Thats pretty much all i did to them, cleaned up the bowls gasket matched and cleaned up the intake, reamed the guides a little for the valves and seated em. Pretty much a polished tird, the casting is 10114156 just a set of heads i had sittin around at the time. Like i said a polished tird. I can post some pics of the head work tomorrow if you want to see it.

[QUOTE=yblow;381141]

Originally Posted by jerry clayton

bowl work, minor clean up of ports, NO cutting of the heads at allQUOTE]

Thats pretty much all i did to them, cleaned up the bowls gasket matched and cleaned up the intake, reamed the guides a little for the valves and seated em. Pretty much a polished tird, the casting is 10114156 just a set of heads i had sittin around at the time. Like i said a polished tird. I can post some pics of the head work tomorrow if you want to see it.

Couldn't find much about the heads except that they probably won't work for any kind of performance application. Here's a comment stolen from Camaros.net....
"I am assuming by L-29 you are using GM head number 10114156 '91-'01 Gen. V & VI 454, "round port" (195cc intake ports ); Open style 115cc chamber; uses adjustable 2.06" intake valve and 1.72" exhaust valve (as opposed to the newer '96 up "Vortec 7400" 10141279 heads with non-adjustable rocker stud nuts). This 156 head is a truck head designed to build torque, not horse power. These heads will fall on their face at 4000."

Hmmm, doesn't sound pretty. 195cc intake ports would be expected to do a good job on a 383 cubic inch small block.

funny your hyd roller with the 1.8 is about the same cam i used from Erson with 621/621 lift 238/246 comes in 108 and 112 . as for a bore 100 over thats ok but i just do not care for the KB hypers seen to many fail . but i do like the new forged line. i would look in to them or a speed pro hyper for low buck build the 4.500 crank works with a cap screw rod bolt rod less work to the block .the 4.500 is the way to go it wil not cost any more and with added deck + more stroke so you at lest want to run a 6.536 rod and SRP make a shelf piston with the right CH for this build

Originally Posted by pat mccarthy

funny your hyd roller with the 1.8 is about the same cam i used from Erson with 621/621 lift 238/246 comes in 108 and 112 . as for a bore 100 over thats ok but i just do not care for the KB hypers seen to many fail . but i do like the new forged line. i would look in to them or a speed pro hyper for low buck build the 4.500 crank works with a cap screw rod bolt rod less work to the block .the 4.500 is the way to go it wil not cost any more and with added deck + more stroke so you at lest want to run a 6.536 rod and SRP make a shelf piston with the right CH for this build

The rods i want to run r 6.7 but i might go 6.536 depending on the price of the pistons between the two. Can you find pistons with a 1.24 ch i need them with at least 10:1 compression with the 6.7 rod i can go with a flat top or small dome. What do you think about running smaller rod journals for more clearance? I can find 2.1 rods and cranks turned down to that, but not sure if its worth it.

[QUOTE=techinspector1;381144]

Originally Posted by yblow

Couldn't find much about the heads except that they probably won't work for any kind of performance application. Here's a comment stolen from Camaros.net....
"I am assuming by L-29 you are using GM head number 10114156 '91-'01 Gen. V & VI 454, "round port" (195cc intake ports ); Open style 115cc chamber; uses adjustable 2.06" intake valve and 1.72" exhaust valve (as opposed to the newer '96 up "Vortec 7400" 10141279 heads with non-adjustable rocker stud nuts). This 156 head is a truck head designed to build torque, not horse power. These heads will fall on their face at 4000."

Hmmm, doesn't sound pretty. 195cc intake ports would be expected to do a good job on a 383 cubic inch small block.

Just found a set of these heads 3931063 with manley stanless 2.19 1.88 valves. The guy wants $500 for em. There closed chamber head and oval port but used in high hp engines. These have got to be better than the 10114156 heads i did all the port work to rite??? Are they worth buying and selling my other ones?

That post is rite on at around 3500 rpm those heads fall flat, ive been having that problem and it ran better when i shifted manualy.

[QUOTE=techinspector1;381144]

Originally Posted by yblow

Couldn't find much about the heads except that they probably won't work for any kind of performance application. Here's a comment stolen from Camaros.net....
"I am assuming by L-29 you are using GM head number 10114156 '91-'01 Gen. V & VI 454, "round port" (195cc intake ports ); Open style 115cc chamber; uses adjustable 2.06" intake valve and 1.72" exhaust valve (as opposed to the newer '96 up "Vortec 7400" 10141279 heads with non-adjustable rocker stud nuts). This 156 head is a truck head designed to build torque, not horse power. These heads will fall on their face at 4000."

Hmmm, doesn't sound pretty. 195cc intake ports would be expected to do a good job on a 383 cubic inch small block.

What about these heads casting 3931063. I found a guy who has these for sale for 500 bucks they have stainless manley 2.19/1.88 valvles no port work.

Just got my parts in cant wait to assemble. Check em out:

Looks like Christmas came early!

Originally Posted by Wayne Gilchrist

Looks like Christmas came early!

Yes it did

So im picking up my block tomorrow from the machine shop and going to start clearancing my block for the 4.5 stroke im know ive got some grinding to do. Does anyone have any advice or a slick way to mock it up to start my grinds? I know ive got to watch out for water. Any help is better than no help

yep i have cut blocks out for 4.750 for alum rods there no ez way .i set the crank in with a piston wipe the wall down good .i put some lube on the skirts so not to mark up the pistons or bores as well as the crank/rod bearing s. you do not need to put all of them in number 5 and 1 will work i have old set up bearings for this job as you do not want any iron dust on the bearing s if so they will turn in to a file and trash the crank .you will have to trim the bottom of the bore cam side and oil pan rail side i turn the crank by hand till it hits then use a big tip marker they are about 1/4 tip .mark out all bores .you want to grind 1/2 of the mark off so about 1/8 of the mark still should be still there . when you grind all the bore s you need to take a 80 grit flap wheel and roll the bottom of the bores if you fail to do this you will trash out your new pistons and bores and have nice new junk . if you want to P.M me i can talk to you on this. if you want. when you get this all done wash your marker marks off the bores clean the block so no iron dust will not hurt any parts , put crank back in the block rod and piston turn by hand. i make up long card boad feeler gages to check for any thing hitting you need about 060 for room. if you do not have that but will roll thru then i mark the spots with a thinner tip marker. take all parts out grind and roll the shape spots off the bottom of bores wash good and check it till it rolls and you have 060 .if you have a older 427 block and you grind to much you will hit water