[69Chvll]

Hey guys, I tore down a 427 I purchased a couple of months ago. Time to decide what I can get away with. The goal of the build, budget and repurpose with 500 ponies to play with.

Here’s the details
427 bored 30 over
Forged pistons
4 bolt main
Unknown block: it’s been zero decked
Solid lifter cam, which needs to be replaced
840 and 391 heads, it’s a miss match. Passenger side is the 840 driver side is the 491.

I’m thinking about a hydraulic flat cam, switching out the heads for something with lower compression.

Here’s pictures

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[427L88]

Remember , its a 427, let it breathe! Shrink the port sizes in the new heads, it will breathe better!

 

[Malibu ss 64]

Do you know the dome size or piston part nr?

 

[427L88]

L2288 is a TRW flat top piston #.

 

[Kopfjaeger]

500+ hp is relatively easy to reach. I recently built one 9.33:1 compression, hydraulic roller cam, AFR 265 heads. 534.hp and we weren’t even really trying!

Joe

 

[Malibu ss 64]

L2288 is a TRW flat top piston #.

Ah now I saw the picture with the part nr its L2268 030 so it has 36.3cc domes. With a 118 cc head you will have around 10:1 in comp so maybe some 781/049 ovals.

 

[69Chvll]

L2288 is a TRW flat top piston #.

L2268


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[69Chvll]

Ah now I saw the picture with the part nr its L2268 030 so it has 36.3cc domes. With a 118 cc head you will have around 10:1 in comp so maybe some 781/049 ovals.

That would be perfect for CR


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[69Chvll]

500+ hp is relatively easy to reach. I recently built one 9.33:1 compression, hydraulic roller cam, AFR 265 heads. 534.hp and we weren’t even really trying!

Joe

Yeah, it doesn’t need to be anything crazy, just something to have fun with


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[Malibu ss 64]

If in budget maybe a hyd roller? Maybe one of the clay Smith cams? HR-8800-9-CSR BBC 454 to 470 CID “Old School” OEM 049/781 heads to a max of 5700 RPM
Or a isky Racing Cam [696265275] - $445.00 : ISKY Racing Cams, Do It Right
Or lunati

Voodoo Retro-Fit Hydraulic Roller Cam - Chevrolet Big Block 272/280

Retro-Fit Hydraulic Roller Cam. Great mid range torque and power. Likes 2000 RPM stall converter and works great in towing applications with lower gearing. Largest for inboard/outboard performance marine use.; Advertised Duration (Int/Exh): 272/280;

www.lunatipower.com

Voodoo Retro-Fit Hydraulic Roller Cam - Chevrolet Big Block 282/290

Retro-Fit Hydraulic Roller Cam. High performance street cam. Likes upgraded intake, carb and exhaust. Needs 2800 RPM stall converter in most cases. Requires 9.5:1 compression for maximum performance.; Advertised Duration (Int/Exh): 282/290; Duration

www.lunatipower.com

pretty sure all above will be very close to meet your goal. What car, transmission, stall, rear gear will it end up in? How are you going to use it?

If you are going with new timing set you might as well get the cam on a gen VI core and use the locking plate of your block is drilled and tapped for



or use the form some camcompanies( comp, Howards, bullet etc) have on their homepage to get a recomendation

 

[69Chvll]

If in budget maybe a hyd roller? Maybe one of the clay Smith cams? HR-8800-9-CSR BBC 454 to 470 CID “Old School” OEM 049/781 heads to a max of 5700 RPM
Or a isky Racing Cam [696265275] - $445.00 : ISKY Racing Cams, Do It Right
Or lunati

Voodoo Retro-Fit Hydraulic Roller Cam - Chevrolet Big Block 272/280

Retro-Fit Hydraulic Roller Cam. Great mid range torque and power. Likes 2000 RPM stall converter and works great in towing applications with lower gearing. Largest for inboard/outboard performance marine use.; Advertised Duration (Int/Exh): 272/280;

www.lunatipower.com

Voodoo Retro-Fit Hydraulic Roller Cam - Chevrolet Big Block 282/290

Retro-Fit Hydraulic Roller Cam. High performance street cam. Likes upgraded intake, carb and exhaust. Needs 2800 RPM stall converter in most cases. Requires 9.5:1 compression for maximum performance.; Advertised Duration (Int/Exh): 282/290; Duration

www.lunatipower.com

pretty sure all above will be very close to meet your goal. What car, transmission, stall, rear gear will it end up in? How are you going to use it?

If you are going with new timing set you might as well get the cam on a gen VI core and use the locking plate of your block is drilled and tapped for



or use the form some camcompanies( comp, Howards, bullet etc) have on their homepage to get a recomendation

Probably a 2200 stall converter. It would be mated with a TH400. The car is TBD. I’ve got some parts laying around I’m going to build something with. Should be fun to see what they end up in!


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[69Chvll]

What do you guys think of these heads? I found them on CL. What type of cam are the springs setup for?

Freshly rebuilt 781 oval port heads with all new parts.
REV 2.19/1.88 x 11/32 valves, Heavy wall K Liners .0015-6/.0018-9 guide clearance
US made 4140 chromoly 10* retainers and locks
Super clean 1.55 dual/damper flat tappet springs installed 135# @ 1.900, 435# @ 1.25, CB @ 1.130
Retainer to guide clearance >.900
4140 chromoly US made screw in studs and guide plates.
5 angle intake, radiused ex valve job, bowls blended.
302cfm @ .600 int, 234cfm @ .650 ex. Ports are as-cast. Decks are fresh surfaced. Chambers measure 122cc


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[-SS454-]

Ah now I saw the picture with the part nr its L2268 030 so it has 36.3cc domes. With a 118 cc head you will have around 10:1 in comp so maybe some 781/049 ovals.

I calculate around 10.5 with a .041 gasket.

 

[Malibu ss 64]

I calculate around 10.5 with a .041 gasket.

I didnt calculate I used info from this

https://static.summitracing.com/global/images/chartsguides/s/slp-l2165f.pdf

 

[427L88]

Hey, thats exactly the kind of head you need! Springs are heavy for a flat tappet, but I'd like to see the psi @ 550-600 lift, no rate is given to be able to calculate. I ran 130/370 and its as heavy as I would on a flat tappet. Those seem adequate for a HYD ROLLER thru maybe 6000, but I;d almost like to see more for those fat arse hyd roller lifters. Plus 427s like to RPM, don't hamper it, spring it up!

PS my 427 swung thru 7000 is why I ran the Isky 8005-a springs and Ti retainers ( and solid flat tappet cam) . Bad boy hit near 8000 on a "stuck clutch once". No float, Sounded super sweet up there.

 

[68Chevele]

Remember , its a 427, let it breathe! Shrink the port sizes in the new heads, it will breathe better!

1/2" of epoxy on the port floor will take car of that and make it a raised runner roval port head.

 

[Aaron]

Study the following link.

Dynamic CR (uia.net)

Study your block and rotating assembly. Figure out your compression with certain cc's. Find what OEM cylinder heads work with the power you want. Oval ports more than likely.
Select cam based off above knowledge for a off the shelf piece or call a cam company and talk with them.

 

[zookpr]

Hey guys, I tore down a 427 I purchased a couple of months ago. Time to decide what I can get away with. The goal of the build, budget and repurpose with 500 ponies to play with.

Here’s the details
427 bored 30 over
Forged pistons
4 bolt main
Unknown block: it’s been zero decked
Solid lifter cam, which needs to be replaced
840 and 391 heads, it’s a miss match. Passenger side is the 840 driver side is the 491.

I’m thinking about a hydraulic flat cam, switching out the heads for something with lower compression.

Sent from my iPhone using Tapatalk

391 or 491, maybe it is really a 291? Many cars came with a mix of 840 & 291. I had one back in the day and thought the 291 was a warrantee adjustment but there was a consensus on here that there are many documented cars with the mix.

 

[-SS454-]

I didnt calculate I used info from this

https://static.summitracing.com/global/images/chartsguides/s/slp-l2165f.pdf

I used the Wallace CR calculator.

How did you figure out the pistons are 36.3 cc when the PDF says .255 dome?

 

[Aaron]

You have homework on your budget and what parts can give you what you want within your approval.

Seek out the old timers who know old setup with old school parts. You can modernize the combo. Cost more money.

I have reposted my previous post.

Pat Kelly was a early member I believe, not sure he around anymore.

Study the following link.

Dynamic CR (uia.net)

Study your block and rotating assembly. Figure out your compression with certain cc's. Find what OEM cylinder heads work with the power you want. Oval ports more than likely.
Select cam based off above knowledge for a off the shelf piece or call a cam company and talk with them.