ricardo.benin

Appreciate it, the head was welded by one of the best aluminum welders is the states for head and block welding. And I think what happened is I must of got valve float or something along those lines. When I bought the car the seller said car is ready to make serious power which it wasn’t, had a rebuilt short block with tomei pistons and a Cnc ported head. and stock everything else, so not sure what was going on in the sellers head but it was my fault for taking his word. I bought mahle pistons, darton sleeves, oil pump drive kit to fix the oil gear, and carillos top of the line rods with there super rod bolts that are supposed to be better than arp. Still not sure on what springs and retainers to run. I’m not sure if I want to run a dual springs because of the added seat pressure and valve train wear.

So my rb26 has an issue where it ate up two valves, damaged piston and bore and damaged head chamber. Anyways I need to figure out what to do. I have a full set of darton sleeves and was thinking of using them and wanted to know what everyone’s thought is on running them. Also my head is Cnc ported and was thinking of welding chamber up and digitizing a clean chamber and milling it out at work. What’s your thoughts. Thanks Richard

What turbo would you recomend. Thanks

Hi I am building up a rb25 and my goal for now is for 450hp and maybe 500 rwhp in the future so will a holset hx35 be ok for that power also I plan on using the stock exhaust manifold as I am going to mod it to suit what I need. Thanks Richard

OK great. Appreciate the help

Hi GTRPSI should I also make the transition from the seat to bowls better or would you just leave that alone. Thanks

Hi guys thanks for all the info. Btw I forgot to mention that I do not have e85 were I live, we only have 92-93 octane fuel so I was thinking of maybe running water/meth injection. I was also planning on putting valve springs and retainers in as well and keep every thing else stock. Thanks

Hi I recently have started my build on my rb25det and the block is at the machine shop. But I am now onto the cylinder head and that is were I am having problems, basically I am trying to find out if I should port the cylinder head. I want to make 450-500hp and I was wondering if I can do without porting. I was thinking about removing the humps in the exhaust ports but what about porting the bowls, should I leave it or make a better transition from valve seat to casting. Btw the machinist is going to use a 3 axis valve seat grinder. Also I found some engine manuals for the cylinder head but non of them for the rb25det has any info on valves and valve seat clearances just a basic cylinder head disassemble that does not include removing valves, so if any one has any tech sheets that would be great as the cylinder head is next to go to machine shop. Thanks Richard

Hi I have to buy a rb25det crank shaft and my question is this the standard rb25det crank part number. Thanks Richard

I am probably going the route kiwi mentioned using 2 x 1mm restrictors instead of blocking off the one port.

Oh ok

Hi KiwiRS4T I plan to run the car street only but I do want to try and make 500hp. Btw what is a external supply to the vct also I will buy the restricts from you once I find out exactly what size the restrictors I have right now are.

Hi KiwiRS4T do you have hydraulic lifters, BTW I like your idea on running 2 x 1.0mm restrictors, so do I put the 1.0mm restrictors in the middle and rear oil feeds. BTW when I looked at the restrictors on the tomei website it says do not use restrictors in conjunction with the hydraulic lifters which seems not to be correct. Thanks

I have read the oil control thread but blocking one feed and restricting the other does not sound like a good idea to me as I am running the car as a street car and hydraulic lifters. People say well the rb26dett has smaller restrictors and one oil hole blocked off but the 26 had solid lifter and not hydraulic lifters like the series 1 and 2 rb25det which means the lifters need a lot of oil. I am thinking of running a line from head to sump but not sure about the restrictors or blocking off a oil hole. Hi Ben C34 I was using a vernier calipers. Thanks Richard

Hi I was looking at my rb25det block and I tried to take a measurement on it any way my micrometer is is to big to measure the oil restrictors. So my question is I am trying to find out if these oil restrictors are stock or after market I came up to a number that seems to small to be stock, the measurement is around .055 which is about 1.40mm so I am not sure if these are stock or not. The number I came up with is probably off as I can not get a accurate measurement. Thanks Richard