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I need a bit of help here with those two things believe me I have searched and haven't found a definite answer. So the plan is to have use a rb25de head from a r33 and a rb30 block, from what I've found people are saying it doesn't matter what head gasket I use, 25 and 30 will both work. Although I am trying to save money where I can here and would prefer to not have to get the block welded and machined flat again. Some say its recommended to weld the water jacket on the block so that you have more surface sealing the water, but can't I just use a rb30 head gasket and everything will be alright? Going from these pictures that I have found:

30 gasket on 30:

http://www4.wave.co.nz/~lakewood/Skyline/R...s-RB30Block.jpg

25 gasket on 30:

http://www4.wave.co.nz/~lakewood/Skyline/R...-RB25Gasket.jpg

The oil gallery on the head will be seal obviously, most likely by using a grub screw as some people have used and it seems cheaper. So if the vvt feed is blocked on the head is it alright to use a rb30 HG so that the water jacket will seal better?

Thank you

compare both gaskets with the rb25de head, you should be able to see what gasket works best for you.

I used the rb30 gasket with a rb25det head, but i already had to modify the head to block the vct oil feed so i just added some meat on the head while i was at it, personally id make the modifications to the head so that if you ever needed to replace the block, it would be a lot easier

Jarrod

Thanks for the feedback guys, I was under the impression that it was the block that needed to be welded and machined to suit the gasket. Thats what I gathered from this picture anyway.

http://www4.wave.co.nz/~lakewood/Skyline/R...30%20Gasket.jpg

Use an RB30 or RB26 gasket and with 25DET it's the head that needs welded.

Oh thats good, I'll be using a 25DE head so that saves me some hassle. I also have a 25DET head so I can compare the differences when i take the 25DE head off the motor. Anyway using RB30 or RB26 head gasket, I won't have to weld a bigger area on the block? Or is that wrong?

Edited by 30ed32

r33 25de and det heads are the same.

the engine builder we use uses an aluminium mig welder and fills in the front water port a bit and fills in the oil feed then gives the head a skim. Its not very expensive.

By doing that you can fit the head to any unmodified rb30 block and use any rb30, rb26 or r32 rb25 gasket

sweet, I'm in Hamilton btw and only know one engine place here and don't think they will do it and if they did it they would charge a lot. Hopefully I can find another one.. it's not really worth the trip up to Auckland unless i can't find anyone.

the de head doesnt have the vct so it doesnt have the vct oil feed in the head that has to be blocked like the det head, it didnt take long or cost me much to get the head welded, took them maybe 5 mins to weld some metal in.. they let me die grind it abit, they smoothed it up, then the head got deck

Jarrod

sweet, I'm in Hamilton btw and only know one engine place here and don't think they will do it and if they did it they would charge a lot. Hopefully I can find another one.. it's not really worth the trip up to Auckland unless i can't find anyone.

give Dick a call at hytech engine reconditioners in manukau. only an hour away from you. they have done all the heads for me and my friends rb30's. dont remember what it cost, but it was a reasonable price and he has done plenty of them

the de head doesnt have the vct so it doesnt have the vct oil feed in the head that has to be blocked like the det head,

Jarrod

the r33 head does, just not the r32

the de head doesnt have the vct so it doesnt have the vct oil feed in the head that has to be blocked like the det head, it didnt take long or cost me much to get the head welded, took them maybe 5 mins to weld some metal in.. they let me die grind it abit, they smoothed it up, then the head got deck

Jarrod

the r33 head does, just not the r32

R32 RB25DE head is straight plug and play, no modifications necessary.

R33 RB25DE/T heads have to be welded up.

thanks everyone for clearing that up. Maybe it would be easier to pick up a cheap r32 25de head? This is going into an R33 btw, and I have heard something about the intake manifolds not fitting or something? Would the 32 head be plug and play in a r33 using all the r33 parts that attach to the head?

thanks everyone for clearing that up. Maybe it would be easier to pick up a cheap r32 25de head? This is going into an R33 btw, and I have heard something about the intake manifolds not fitting or something? Would the 32 head be plug and play in a r33 using all the r33 parts that attach to the head?

The intake manifold bolt layout is different, the R32 RB25DE head is the same as RB20 and R33 RB25 intake manifold don't fit on RB20 heads.

I am using an RB25DE head retaining the VVT. I understand they have bigger valves than the RB25DET heads. Gasket is a Tomei RB25 item.

+1 for ringing Dick at Hytech engines - he does a lot of RB30 stuff and you can always courier him the head if necessary although its just over an hour's drive away if you need to take the block in.

yeah thanks guys i think thats my best bet is taking the head to hytec and get them to match the gasket.. some people are saying head some are saying block? I guess i'll have a look when i get the heads off and compare gaskets and go from there.

thanks I remember seeing that a while ago i just forgot, it doesn't look like there was any extra welded on... just vvt blocked and the hole reshaped, but thats probably just me not looking closely enough. Thanks for all your help I will take head into hytec and get them to sort it out for me.

definately 100% the head thats needs modifying

awesome.. just hope its cheap enough and i hope this helps someone else out in the future, maybe I'm just a bad researcher but I couldn't find such definite answers anywhere else. Thanks guys should be running in a few weeks hopefully once I have all the parts

  • 2 weeks later...

all rb25's run same size valves, rb26 valve heads are 1mm bigger then the rb25

the rb25's with vvt have an oil return under the intake cam, which fouls with the water jacket in the rb30 which will mix water and oil, dont want to weld it? tap it and lock tite a grub screw in, want to still use vvt or just drain the oil tap the hole in the front

there is no other welding needed

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