My 1995 GTR project thread.

[cortexx]

I had the head assembly to drop off this week also , they cc'd the combustion chambers to see if it's ever been machined before ( which it hasnt ) , and so they can work out the compression ratio and decide how much to skim it and how thick the head gasket needs to be to give me 8.5 :1 compression ratio. I'm still a bit indecisive on the head. I want to ditch the sodium filled exhaust valves because they are prone to snapping off using non factory cams.

I thought poncam b's would be ok on the factory valves but the increased trailing angle on the exhaust lobes with apparently add stress to them as them slam shut at a greater rate due to the extra duration so im going solid valves . not sure if i need to change the inlet valves too - they are already solid. I could always order a supertech head kit (phosphor guides , Nitrided inconel exhaust valves , titanium retainers , springs, stainless inlet valves and be done with it and sell the hks step 2 spring kit i have. More research needed ...

I posted elsewhere about oil pump choice , I think i'll probably procure a Tomei pump - it seems like the logical choice - these is so much debate on this subject it's almost impossible to make a solid decision based on any type of reasoning from points of view so i'm going to pay the extra for piece of mind..

I know i said i'm installing this all next winter but i'm excited as hell to get it running ..

[gtrjon]

what size cams do you plan on running? i was so torn during my build if i wanted to spend the 500 bucks on a set of valves but i came to the conclusion that the oem sodium filled valves are strong and will hold up with the proper valvetrain. keep in mind i am running decently large sized pro cams. 270 duration 10.25 lift. glad to see you came around to the tomei a few hundred dollars is definitely worth the piece of mind.

[nimblestix]

I had the head assembly to drop off this week also , they cc'd the combustion chambers to see if it's ever been machined before ( which it hasnt ) , and so they can work out the compression ratio and decide how much to skim it and how thick the head gasket needs to be to give me 8.5 :1 compression ratio. I'm still a bit indecisive on the head. I want to ditch the sodium filled exhaust valves because they are prone to snapping off using non factory cams.

I thought poncam b's would be ok on the factory valves but the increased trailing angle on the exhaust lobes with apparently add stress to them as them slam shut at a greater rate due to the extra duration so im going solid valves . not sure if i need to change the inlet valves too - they are already solid. I could always order a supertech head kit (phosphor guides , Nitrided inconel exhaust valves , titanium retainers , springs, stainless inlet valves and be done with it and sell the hks step 2 spring kit i have. More research needed ...

I posted elsewhere about oil pump choice , I think i'll probably procure a Tomei pump - it seems like the logical choice - these is so much debate on this subject it's almost impossible to make a solid decision based on any type of reasoning from points of view so i'm going to pay the extra for piece of mind..

I know i said i'm installing this all next winter but i'm excited as hell to get it running ..

Any idea how much the supertech head kit you spoke of costs? The only thing I didn't do for my build was upgrade much in the head, and I might pull it apart by mid summer to get it done. Im running first Gen B poncams.

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[gtrjon]

marvin at autodream can hook you up as he is a supertech dealer. dual springs/retainers ~500, bronze guides ~150, valve stem seals ~20, and then if you want to run big enough cams (anything over 10.4mm of lift i think they specify) tomei sells a shimless bucket set for ~ 450 that is nice. add cams on top of that and you can basically have a well put together head for around 2000 bucks with machining.

[evilgtr]

what made you decide on the dual Tial bov's ? I have 3 BOV's that I switch out once in a while just for a different sound (they are all attached to there own I/C pipe so takes less then 5 mins) 1 of them is a 50mm Tial and its loud !! couldnt imagine having 2 of these it would sound like a screamer pipe hahaha what color is the 9lb spring ?

[DJ]

I wasjust about to ask the same question, I would think that 1 would suffice.

[cortexx]

A single tial would be loud , i decided on them because they were for sale NEW from a GTRCer for a good price , they are made in the US and the company is easy to deal with if I need any parts or need to call them ( already had to thanks to canada post losing some of the parts ) . A Pair makes alot less noise than a single one due to the venting volume being evacuated by the 2 rather than 1. And i might go a different route for turbos later some time

The cams i already have are Tomei Poncam B's , im moderately over building everything incase I want more power later

[Phastwon]

Looks good Paul. I have the same ATI race dampner and it is a nice piece. Keeps things running smooth for sure.

[Nathyne]

Love the thread just read it from page one excellent quality of work you're putting into it!

[cortexx]

Small update to the log :-


Active engines called yesterday and gave me a few updates , the block is ready to go together and the head is stripped . They had it xrayed for cracks and found it was a good casting BUT found 4 cracked valve guides. Funny thing is that the head had been rebuilt at some point and the valves replaced but the builder obviously didnt check it properly enough. The valve seats are brand new . He said the previous engine must have had an interference problem , maybe cam belt broken with pistons hitting valves etc. Will be double checking the cam journals to make sure they are not warped and are aligned ok.

They have calculated that the current compression ratio is around 8.2 to 1 so they will be planeing the head down to make it 8.6 to 1 with a 1mm head gasket.

I finally decided on the supertech valves (inconel exhaust and nitrided inlet) along with a complete set of supertech guides . They are ordered and will be in my hands by the end of the week. The HKS step 2 springs are with the builder and I have to make a decision on ordering a new set of oem retainers and collets , or maybe ditching that idea and going with either a supertech spring / retainer or a brian crower spring and retainer kit. Tried looking on the net for info on the limitations of the OEM retainers and didnt find much .. more research needed !

Got a complete OEM nissan heater hose kit this week ( all the rubber under the plenum basically ) , I am considering doing away with the water,oil heat exchange contraption as im sure the HKS oil cooler more than makes it redundant. Would be nice to simplify things a bit.

Also considering my options with the idle valve assembly too , wondering if the vipec can control idle and off idle enrichment without the need for it. Would be great to lose that too. Vlad was telling me they don't use them on their cars , i'll have to pick his brains again!

Word is the tomei exhaust will be here soon , a few words on the tomei facebook page about the wait time seems to have generated a steady stream of personal update messages which is good - nice to see a company stepping up and keeping the waiting informed . Can't wait to install it - pictures will be forthcoming of course ..

[frankiman]

i saw yours and chris' messages on Tomei's post on FB, i keep laughing everytime

[cortexx]

Off to get the emmissions test done - wish me luck guys

[frankiman]

does this mean you have received your Tomei exhaust ?! i wonder..

[cortexx]

not yet frankie but it passed

[1989blackskylinegtr]

nice ride. love the color.