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I've been thinking about what exactly to do with This over the last month or so. Being the Xmas period and speaking to various people with beer involved I've now decided to pull the block out and put some forged internals (reasonable priced stiff) with an N1 pump and spline drive kit. This way I can wind the turbos up to about 1.5-1.6 bar and not have to worry about it. Pistons I'm thinking 87mm to get the 60cc extra (which I know isn't much but I'm going to get the block bored anyway)
Il be able to paint the block nicely and clean the bay up too. I've not budgeted for this (time or money) so it'll be a project that I hope to get running late summer, and run in ready for mapping. 600+hp flywheel is my goal which is very achievable. The goal is to get as quicker spool and low down torque I can with 2.6L
Sound like a good plan my only advise would be to not focus on capacity for your rebore at this level the extra capacity will make no noticeable difference. These blocks are now getting very difficult to source second hand (read expensive). Therefore if something goes wrong at 87mm your block will be scrap or you will need to sleeve it (again expensive).

Why not go 86.5mm then you have some margin for a future rebuild?
 

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Another thing I did was this... View attachment 247875
Taking away the sharp edge will help reduce hot spots and also will help flow of gasses around the valves. I believe that on the gt500 head they took the lump out all together but I don’t want to kill response off boost completely.
Thats the squish pad and its purpose is to transfer heat away from the piston and prevent detonation, it has nothing to do with flow or response.

Interestingly if you search for pictures of nismo built heads they remove the quish pad on one side of the chamber (exhaust from memory). Other engine builders remove them completely

They will effect how det limited an engine is on a certain grade of fuel and I have never seen any results with/without to prove any benefit
 

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Discussion Starter #44
Sound like a good plan my only advise would be to not focus on capacity for your rebore at this level the extra capacity will make no noticeable difference. These blocks are now getting very difficult to source second hand (read expensive). Therefore if something goes wrong at 87mm your block will be scrap or you will need to sleeve it (again expensive).

Why not go 86.5mm then you have some margin for a future rebuild?
Good advice there. Yes 86.5 might actually be an option. Il have a think about that for sure. It’ll still give me 30cc I suppose too.
 

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Good advice there. Yes 86.5 might actually be an option. Il have a think about that for sure. It'll still give me 30cc I suppose too.
1.15% increase so on your target 550hp, 6.3 hp! :eek: (assuming the turbos are not maxed out), with a corresponding 1.15% reduction the in the point the turbos build boost.
 

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Discussion Starter #49
....so I’ve not been doing too much over the last few weeks. I had some spare time yesterday so decided to give the engine bay, block and gearbox a pressure wash down. 67A29C6C-760A-4BF3-ABF8-4BE85293D164.jpeg
A bit of a rubbish pic but you get the idea!
Some more stuff coming including a supertec spline drive kit and Tomei sump baffle. Engine stand arrived today so il get a pic once the blocks on it.
 

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Discussion Starter #56
29BC471A-DFCC-4F5F-8B97-B02DD3D00F0D.jpeg ...supertec spline drive kit arrived today. Very nice bit of kit and fast delivery. Tomei sump baffle is also here so all I***8217;ve got to do is get a pump to put the spline drive kit in and I will have collected all the engine oiling modifications:thumbsup:
 

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Discussion Starter #58
A quick update

Things haven't really moved on with this a lot, but I have been collecting parts. I've had a couple of hours spare this afternoon so thought it would be a good opportunity to pop a cam in and measure the valve clearances. If I'm honest I've not been looking forward to doing it because I thought it would be boring.
It's actually not that tedious. I just did the exhaust side for now.
As I understand the figures I'm looking for are 0.38mm ex, 0.45mm in. Nissan say +-.03mm on both sides.
It was a little awkward getting the feelers in but much easier after I "adjusted" them. image.jpeg
 
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