FAQ For Twin Cam Cylinder Head

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Revised 6/24/2022

This is not now nor will never be an open box, install head affair. The head casting is just the staring point for a competent engine builder to put their “mark” on the head. I feel this is the best way forward so that you are not tied into purchasing parts that are not appropriate for your build.

I’m constantly updating this list.

1)What’s the price?


The head comes loaded with valve seats and guides. Some of the things needed for completion are porting, valve job, cam lobe grinding and head assembly.  The best thing to do if you are truly interested in a head is to start a dialog with whomever will be building the head and work outward from there.

2) Will it have VCT and variable valve lift?    It won’t have variable valve lift but it can have VVT. I have it running on my head and I seem to have all of the bugs worked out. I personally feel the money would be better spent elsewhere but from a technical standpoint nothing is standing in the way. As of now I have no plans of offering this since I personally don’t have time to make it happen.

3) What alloy is the head.  The head casting is A356 aluminum heat treated to T6.

I4) What will it flow? I had the prototype Flow Tested     This is with minimal porting done. Here are the flow test results on V2 after Rebello did some port work on it. Rebello figures that the ports can easily support 600 HP normally aspirated.

5) Any provisions for coil on plug ignition scenario?  Yes. The valve cover has bosses on the inside so you can point the wires towards the front or towards the rear. It is pre drilled to point the wires to the rear.

6) What are you planning for intake and exhaust manifolds?  I’m casting a single DCOE manifold and that will be used 3 times. The inner ports are formed with 3D printed sand so there isn’t a part line to deal with. For now headers are custom for each build and has been handled by the builders.

7) How much horsepower is it putting out?  SN/004 was built by Rebello along with a 3.5L engine. It produced at the crank 492 hp at 8000RPMs and 360lbs of torq at 6000 RPMs.

8) Why didn’t you use the Honda timing chain?  The crank gear was too small to fit over the snout. single chain was my preferred route but there was just no way to make it happen. At least not with off the shelf components.