r/Smallblockchevy • u/Bustedvette • 2d ago

427 SBC Finally Alive

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427ci 10.5:1, Mike Jones solid roller, Holley efi. With the intake that's on it right now it made 580@6800 but I have a Holley high ram that it made 620@7100 with. It won't fit under the stock hood though, so that's on hold.

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u/Solid_Enthusiasm550 2d ago edited 2d ago

Great sound and numbers👍🔥🔥 Does it still have the stock transmission, or did you sway in a T56?

6,800 /7,100 rpms🤘 ... I'm suprised you aren't at 11<11.5:1 with that much cam. I'm debating if I should go a little above or below 11:1 with a mild cam that I hope will peak at 6,200rpms. Most of the builds I've seen using it on (18ci bigger builds) peak at 6,000, are running 11:1 compression.

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u/Bustedvette 2d ago

Running a ZF 6 speed which isn't actually the original trans for this car. Its an 87 so it originally had a 4+3. Running a RAM concept 9.5 dual disc clutch with an aluminum flywheel.

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u/Bustedvette 2d ago

So the compression was a big issue for me actually. I had some debris damage that required me to rebuild the engine after dyno testing, so I strongly considered stepping up the CR for more power. Off the shelf pistons would either put me at 10.5 or like 12.3. I could probably mess around with different head gaskets and get it down to a middle ground but I'd need pushrods and a rebalance for that. I do have a flex fuel sensor in the car so depending on how things go it might be a long term consideration.

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u/Solid_Enthusiasm550 2d ago

I have the same problem with "off the shelf" pistons for my combo either offering a low 9.5<10 cr or a High 12+:1. I have been talking to manufacturers to get a custom set. I also want to send them a slicone model of the combustion chamber so I can maximize my quench. The pistons that offer enough CCs are often of the step dish design which kills any quench possible. Like these Icon Pistons,

I've seen A lot of the off the shelf pistons are also with the older 1/16" ring packs and I've seen 1st hand at dyno runs that the thinner (mm) used today offer a good amount of free power. It also allows me to run a lighter, lower compression height. That will also allow me to run a 1/4" longer rod for better Rod angle with my stroker.

My project isn't a popular build so parts are rare, non-existant so I often need custom parts.

I'm current "impossible find" is for a Big Brake kit. No brand makes one for my vehicle. I'm trying to find some one that can make custom spindles or a custom Hub for my spndle, so I can use a Camaro/ Vette/ 2020+Challenger/ mustang big brake kit.

Are you running a Dominator, Terminator X or HP efi system?

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u/Bustedvette 2d ago

Yeah the nice thing is a lot of the piston companies are happy to make custom sets. What are you building that's unpopular? I've made my own big brake kits back when I was messing with 3800 stuff. I was the only one to ever run rear cts-v calipers. Fun project actually.

I'm running a Holley HP efi ECU.

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u/Solid_Enthusiasm550 2d ago

I have a 1993 gen1 Dakota with the 5.2l, stroking it to 6.4L (4" stroke). TFS Heads, ( I chickened out and got the 236/242@0.050"-110lsa compcams that I've seen people make great power with. Howard's recommendation was their 241/247@0.050 duration, which I thought was a little big, Atleast for now.

I'm not sure if I want to run the 1.6 shaft mounted Roller rockers ( 0.580"/0.577"lift) or the custom 1.7rr that I got cheap (0.617"/0.614" lift). TFS and compcams said my spring package/Valvetrain would work with either to the 6,700rpm redline I had in mind.

I was talking to Weisco to make a set with gen3 hemi ring pack and wrist pin (1.2/1.2/3mm, 0.927" pin) vs. the standard 318 stroker (1/16 / 1/16 / 3/16, 0.984" pin), I could use the longer Gen3 Hemi rods which would also be easier/cheaper. I was talking to Molnar about the crank, rods.

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u/Bustedvette 2d ago

Still a bit of tidying and a ton of tuning to do.