defrag010 Posted October 2, 2006 Share Posted October 2, 2006 I am about to buy a set of VG30 heads, and was wondering if there is any difference in the n/a VG30DE heads and the TT VG30DETT heads ? Quote Link to comment Share on other sites More sharing options...
LordZ Posted October 5, 2006 Share Posted October 5, 2006 Yes, they are different. Russel from Z1 sums it up nicely with this: I have been studying the differences in NA and TT heads for years with no great revelations until last week. The castings are the same externally, except for the fact that the TT has 40P stamped on it and the NA has 30P on the side. I knew the TT had a different alloy exhaust valve and that the Auto TT cams were less aggressive. Valves are all the same size. Lifters, springs, retainers, valve seals, guides, etc are all the same. I had heard that the thickness was different above the combustion chamber, but after measurement it isn't. Nothing explained why Nissan would actually make seperate castings for NA and TT. I had taken some heads to my engine builder for some radical port work a few weeks ago. We decided to get the best port work out there that we would slice some heads into sections to see just how much porting can be done without getting into water or oil jackets. Then we would flow test different designs. After slicing a few heads apart we found that the intake runners on the TT heads are of a different design, corresponding to the different needs for a Turbo application. So the casting is actually different. It is a noticable difference once you start getting deeper into the head and comparing between the two. Some of you may have already figured this out but I figured I would pass along the info. Russell Floyd Z1 Motorsports Quote Link to comment Share on other sites More sharing options...
datsunscom Posted October 6, 2006 Share Posted October 6, 2006 After slicing a few heads apart we found that the intake runners on the TT heads are of a different design, corresponding to the different needs for a Turbo application. So the casting is actually different. What kind of tease is that? While yes it answer the question of if they're different it's vague as to the exact differences. What does "corresponding to the different needs for a Turbo application" mean? It's like saying "the cure for cancer is in this foreign language answer: 'pollyimainint frishet ben colqurir' " but not telling us what the translation is. Pictures would be great for those of us now knowing what that means without pictures and arrows.. Even w/out pictures this is better info than I've seen previously though, thanks! Quote Link to comment Share on other sites More sharing options...
LordZ Posted October 6, 2006 Share Posted October 6, 2006 Got me. Can always give John a call. All us Z32 guys normally just get a pair of used TT heads for the swap. They aren't that expensive. I use the NA blocks for the build up and slap on some TT heads and call it a day. Need to watch out for the oil squirters too if you run with stock TT pistons in the NA block, they are designed to flow through the piston, now if you go with forged, the na squirters should be fine. I've never heard of any failures on this, just an FYI on block differences. A search on tt.net might dig up the detailed differences though. That was just a post I recalled from memory over there. Quote Link to comment Share on other sites More sharing options...
datsunscom Posted October 6, 2006 Share Posted October 6, 2006 Thanks for that info. My DETT is tired and needs a rebuild, I do have an NA VG30DE and should pick up some TT heads so I can have a rebuild under way while keeping the current TT in the car. I have seen the TT.NET write up on NA/TT differences and it's a good one. Quote Link to comment Share on other sites More sharing options...
defrag010 Posted October 6, 2006 Author Share Posted October 6, 2006 hmm, I was just wondering because I was given some VG30DE n/a heads for free, and I was going to rebuild them and sell them. Quote Link to comment Share on other sites More sharing options...
tlmaniac Posted October 8, 2006 Share Posted October 8, 2006 the heads that go to my vg30det from a cima are way different that the tt heads.port entry is a lot different and larger and a true oval port i fi knew how to upload pics here i would up load some pics of the port entrances. Quote Link to comment Share on other sites More sharing options...
260DET Posted October 9, 2006 Share Posted October 9, 2006 the heads that go to my vg30det from a cima are way different that the tt heads.port entry is a lot different and larger and a true oval port i fi knew how to upload pics here i would up load some pics of the port entrances. Thats interesting, I've got a VG30DET which is being rebuilt, using a GT35R. Have been told that its block is stronger than the TT block but thats hard to believe. What gasket set are you using? Quote Link to comment Share on other sites More sharing options...
tlmaniac Posted October 28, 2006 Share Posted October 28, 2006 i am working on getting the gaskets imported i have the part numbers and a screen shot from a jap market FAST on my comp at home.unfortunately im in mobile alabama and my comp is in fl.when i get home i could send them to you or you could comtact beck at z31.com he is the one that sent the pn to me.hope it helps.also cometic said they could reproduce them for me if i send them the old gaskets.so you have 2 options Quote Link to comment Share on other sites More sharing options...
260DET Posted October 30, 2006 Share Posted October 30, 2006 Thanks for the offer, the local Nissan dealer is chasing up the info for a gasket set, wait and see how they go. Quote Link to comment Share on other sites More sharing options...
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