Hybrid SR Block Swap S13 Head on S14 Block

[ItzGenX]

As some of you may know, I pulled the JGY disaster S13 SR block out of my car and planned to replace the block with a fresh S14 block. Everything about both are the same as far as bolt holes and such go. All is the same except this minor deal on the surface of the block. The S14 block seems to have an extra oil hole with a restrictor that the S13 block lacks. It is probably used for VTC. The problem?--I am trying to throw my old S13 head on this thing. Lets refer to the extra hole as the VTC hole. As for blocking the hole off, it is easy. Most metal head gaskets have that extra hole in the gasket. The S13 head should seal it off nice and fine because the head has a nice flat spot right there with no hole. The thing that bugs me is that the S13 head has an oil restrictor right next to the head bolt passage where the S14 block lacks this restrictor. How would some of you go about tackling this minor difference between the two? Here is a picture I just took to show what I am talking about. The main concern is the hole without a restrictor in it on the S14 block.

[Jesse SR20]

You could always get a threaded plug, drill and tap the un-restricted hole in the s14 block, install the plug and then drill out the center with an approriate size drill bit. Thus creating your own restrictor.

I would plug the extra restricted hole while you were at it. I don't like the thought of a pressurized oil passage going to the head gasket.

[ItzGenX]

Thanks for the reply, but I already have the info I needed. I found it on some australian silvia/180sx forums. A Toda representative said that the cams will naturally restrict and regulate that oil going through the hole. It feeds the cam journals (round part, not lobe part). He also showed many pictures of some Toda built SR's with different heads on them. As for that VTC hole, he said I don't even need to plug it, as it plugs itself (I was right about that). The pressure that runs through the VTC orifice is roughly 10-15psi and will be nice and easy for the HG to hold (he pointed that out). Also, a properly installed head gasket will not leak even if it were 80psi (aftermarket metal head gasket, not stock cardboard).

All-in-all, ANY SR20 RWD head can be installed on an S14/15 block as long as a S14/15 head gasket is used with no modification (just be sure to have the surfaces cleaned and checked for flatness). S13 blocks can only take an S13 head and can never use a VVL head without major modification (external oil feed).