427 SBC

[87 supreme]

Thank you... and mid to high 10's are my goal. I went with the dart block for more reliability with the 4in crank. I wanted a engine that puts a smile on my face everytime i stab the pedal. Anyone on here have a similar build that could share some personal experience.

 

[565bbchevy]

Looks good and I think you picked the right heads for you combo, do you plan on installing lifter valley screens in your block as a safety measure?
I plan on buying those same valve covers off Ebay when I get farther along in my sbc build but I will strip and polish them like I did with my big block.
I have also been running aluminum heads on the street for about 15 years now with no issues first Darts and now AFRs

 

[87 supreme]

Thanks for the vote of confidence, I'll look into the valley screens. I ordered the whole top end from whites performance and machine they have great prices on those valve covers. The finish on the valve covers is actually pretty nice and the welds are well done. I went with a single plane intake as per AFR they said a 427 wouldn't mind missing a few foot pounds of torque down low and that to take full advantage of the heads they really need a high flow intake. Looking into the intake its a wide open straight shot to the runners, intake ports line up well too the ports. This is the baddest engine I've ever built and I'm trying to put some thought into it rather than just throw parts at it and hope for the best. I added a pic of the conversion kit I installed on the 406 no more thrown belts.

 

[86judge]

Just stummbled across your build. Looks awsome. I've been researching the same idea. Did you have to clearance the block for the 4 inch stroke or dose it drop right in. I was going to build a 400. But I figured by cutting out a lot of the machining cost it wouldn't be that much more to run the dart block. I've been wanting to build a big inch small block for years, and its my next project so any insight on problems would be apreciated

 

[87 supreme]

To be honest with you I had the shortblock fully assembled, But I can tell you the dart block needed to be clearanced to fit the 4in stroke. Not by a whole lot but it needed to be done. I used a callies compstar crank with eagle 6in stroker rods. This allowed me to use a regular base circle cam without problems. Every crank/rod combo is different so you may end up using a reduced base circle cam. I was going to use my 400 block at first too, but was told by my local machine shop(who builds a lot of 427 434 dirt track engines)that it would work it would be on borrowed time.

 

[Fox80]

Looks good, your machine shop gave you good advice on the stock 400 block. They are a hope and a prayer at best, with circle track stuff I always ran a Dart little M block, before we had a 410ci limit the 434 ci configuration is a tight fit to maintain a stock circle cam, like you said every combo is different but with a Callie's Stealth crank and Oliver rods it still worked with minor machining, however I ran a roller cam bearing block with a raised circle cam. That should prove to be a very stout motor

 

[BuWaGone]

Wow, sounds like you're gonna have a beast! One question though, why only 10 to 1? With that big of a cam bleeding of cylinder pressure and aluminum heads I would go for mid-upper 10s. for compression.

 

[87 supreme]

Well in the one horse hick town I live in we only have 91. I'd rather be on the safe side of detonation issues. 20cc dish pistons .005 deck clearance .039 head gaskets 65cc chambers I should be right at 10.25 to 1, I worked with bullet racing when they ground the cam and it,ll work with 10 to 1. I do agree with you though I would of liked to be close to 11 to 1 just with the quality of gas I,m easily able to obtain I went conservative.

 

[BuWaGone]

On my 91 octane gulping daily driven 383 I was at about 10.5 according to summit's comp. calculator. 2 VR(+5cc) flat tops, .025 in the hole, .039 gaskets and 64cc chamber aluminum Patriot heads. But yeah, better to be safe. But my next engibe is gona be 9 to 1, can't have too much compression....

 

[87 supreme]

Well its ready to install and fire up, Just have to finish my garage its about done and time to move everything out of my shed. TOO many projects started on a Power company Lineman's pay scale. Any ways I've changed a few things for the better.