gtir water jacket

noriek2003

New Member
didn't get round to looking at my scrap head and block this morning. I'd forgotten it was buried under a pile of evo interior which i couldn't be arsed to move, so i got on with something else on my car instead.

the evo stuff has been moved now so i'll have a look tomorrow
 

fubar andy

Moderator & N/W Rep
Staff member
am in process of lashing it all back together, quick sharpish as ive a trackday at brands booked in just over a week.
i really dont know how long it will last but i only want it to last for 4 events (im asking a lot there lol) then il build another over the next few months.
How come you backed out of TOTB if its going back for a trackday? :sad:
 

takumigtir

New Member
Hi Bobby, I've just read through the last 6 pages and there are some very good points. I'm not sure whether you remember me telling you that I work at the Nissan Technical Centre near Milton Keynes, in the Engine Test section.

I was down, getting a few bits and pieces with Chris that time and what I can do, tomorrow, is talk to a guy I work with, who actually developed the sr20det cylinder heads. I know before I started there, they had been testing the sr20det a few years previously. So I shall see what I can find out for you and hopefully be able to get the answers to all your questions in relation to the problem you have in hand.

From what I know, in past experience of actually testing Nissan built engines, in the most extreme ways possible, which include testing with coolant temps sustained at excess temperatures of 125degrees, also for example trying to keep the engines at a steady temperature of, say, 80degrees+ or -5 degrees at full load steady state.

You would be amazed what a difference something so little like an extra 100 or 150mm of pipe can make to the temperature, just because the volume of extra water, as you already know, now as far as I can see in the cooling side of things your covered, so the problem that remains is, or could be affected by a few things e.g.
The running temperature of the engine can be affected by a number of main things from: Oil which is the main thing in the engine that actually is responsible for how much temperature is generated by the engine in relation to the amount of heat that is developed through friction that is generated by moving components of the engine.

The question being is there another oil that may work better at the higher temperatures and rev range of the engine which again the question could be asked as I don’t know myself is there any more cooling that you can help to assist in keeping oil temps down a slightly bigger cooler or possibly more cooler oil being re directed to the head which is possible and will also help in respects to the thermal hot spots I think possibly you should bare this in mind this along with a couple of other things will I thing sort out your problems or help at least.

The next thing that has also been mentioned is temperatures generated in the combustion chamber keeping these down as much as possible will also help with your Thermal hotspots as you already know but how many ways are there to do this I can think of a few but what needs to be remember is what kind of consequential performance losses you may get which matters.

A few that I can think of off the top of my head are c/r what boost are you running and what head gasket are you planning on using if you can increase the volume of your combustion chamber to drop these temperatures I think you will benefit you have a few options can you run a slightly thicker head gasket then what you are and adjust your mapping to compensate and slightly more fuel is never really a bad thing the differences I see at work in temperatures if the engine starts running slightly leaner can be amazing to stop everything getting to hot making sure there is plenty of fuel will help all this un wanted heat, another thing that will help you ever so slightly on this matter is can you lower your intake temps intercooler wise ????? Or would you be better with a water based cooler??????

Sorry if it seems like I’m rambling but I think all these things combined all together will help!

The last thing that I will talk about is to do with what everyone else has seemed to have hit on which is the consequential result (localised overheating )within reason as a result of the engine as a whole generating to much heat as an entire unit let it be due to c/c temps or oil temps, or as you have said lack of cooling(which you seem to have sorted volume wise but not circulation wise)
If all of the above are as good as they can be and you are left with your present problem still then yes the easiest and probably most affective way of increasing the flow rate of the cooling system is to plumb in an auxiliary water pump which to be honest I think along with plumbing up the rear of the head with an outlet will sort but this is just my opinion.

As I know how much of a difference this makes from doing it at work its simple but very, very effective and I honestly don’t think it will cause you any major consequential damage to the engine as a whole you may need to change what pressure cap you are using on the rad the thing you can remember with this is that by upping the pressure on the cooling system by using this pump then at least it wont be pressure caused by excessive heat and boiling and is pressure caused by increasing the volume of water being circulated at a lower temp which is always better, I would concentrate firstly though on the cause of this heat and where it originates from and you cant go to wrong I hope this is some help to you :)

I think that’s everything , again that’s just my view on it and I will let you know what the guy at work says
 
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pulsarboby

Guest
How come you backed out of TOTB if its going back for a trackday? :sad:

just explained in other thread andy:)




takum.....:shock: thats a long but interesting post.
would be great if you could have a word to see if any alterations are possible to aid block and head cooling (also any known heatspots).
i believe danny and kieron between them have it summed up really with regard to the swirlpot, electric pump and head design, mainly being to match combustion chambers in head to size of rebore.

good point with intake temps though!
perhaps a chargecooler would be an expensive but far better option in keeping the charge temps down, as youve just suggested!

with regard to oil....i use Q8 fully synthetic which is used in btcc so would have thought that would be quite adequate, have also previously used silkolene pro but no difference there so cant see as its an oil overheating prob, plus oil temps on track dont exceed 110 degrees which is within both oils capabilities.

regarding the h/g ive gone back to a 1.2mm from 2mm as i found the 2mm gasket made the car far too laggy coming on boost (that was with 9:1 comp pistons), i was losing maybe nearlly 1/2 a second everytime i changed gear and in a course of a lap that equates to some noticable time difference, plus at circa 380bhp im not really pushing the car to its limits at 1.5 bar so thought the 1.2mm jobbie would be a safe and very usable compromise.

as just said would appreciate if you can get any further info on this subject, theres been some very good points made by various people so ive got a few things to consider when building the next engine, but obviously my immediate concerns would be if any improvements can be made to the head and block water passages before i commence the build, the rest can be taken care of at a later stage.
 

noriek2003

New Member
i'd stay away from a charge cooler if iwas you bob, to much extra weight and probably not as efficient on a track car as a 'decent' intercooler.

still not looked at that head and block yet....think i've got swine flu as a feel abit stranger than normal
 
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pulsarboby

Guest
i'd stay away from a charge cooler if iwas you bob, to much extra weight and probably not as efficient on a track car as a 'decent' intercooler

how much do they weigh then? cant be as much as my fat gutt:lol:


still not looked at that head and block yet....think i've got swine flu as a feel abit stranger than normal

ive had that for the last year or so then, its good to feel strange it makes you kinda different:lol::lol::lol:
just when you get the chance will be grand kieron;-)
 

noriek2003

New Member
pulsarboby said:
how much do they weigh then? cant be as much as my fat gutt:lol:
you've got the extra weight of the pump, rad, height exchanger, header tank, water in the system, feck knows what that weighs in total buts it got to be heavier than an intercooler
 

PobodY

Moderators
Staff member
It would probably be easier to put a spray bar on your intercooler.
Why not remove a window washer bottle and nozzles from another car; then you've got a resevoir, a pump, and the sprays... and you know it'll run off a momentary 12V feed. That can't weigh as much as a charge cooler, and you could feel special like the EVO and Imprezza boys.

The best thing would be to get reticulation fittings and use them intstead, but there's not much call for reticulation in the UK (whereas in Australia I could probably get 180 degree spray heads from the supermarket).
 

takumigtir

New Member
I think the weight of a charge cooling system is a small price to pay for the benefits and efficiency for example say you are running a front mounted intercooler with all its piping now the time it takes to fill the entire boost system with the amount of air adequate to achieve your desired boost lets say 1.3 bar is time lost so if you want to reduce this as much as possible by putting a charge cooler with a much shorter route will already have big benefits, secondly the capabilities of a charge coolers cooling and efficiency of its cooling is in my eyes much better then that of the intercooler the reasoning behind this is that a charge cooler will not be affected say for example on a slower section of a racing circuit where the front mount wont get the enough air passing over or through the core to cool the boost air as much as would be liked resulting in a loss of performance again due to higher intake temps, as for the charge cooler I would think that you would see intake temps anywhere in the rev range or at any speed over 35degrees this makes me say the improved and constant power and running gains would be much more of an advantage especially on a track you could also take into account the fact that its much less likely to be damaged if you did come into front end contact with someone during a race and it also gives your rad abit more room to breath, but this is only my opinion. As for the other conversation regarding info on thermal hotspots in the sr20det ive talked to the guy at work and during testing of the engine the only damage due to overheating was sustained between exhaust ports as a result of basically no cooling at all, the reason It got to this stage was actually due to where the coolant temperature sender is located in the block so it did not pick up on the head basically being dry until the level of the water drops down to the temp sender level or the remaining waterand build up of air in engine heats enough to give you some warning by this time im sure the damage would be done.
I personally Bob would think about using a second temp sender located on the rear outlet of the head so that you have an accurate head temperature reading and coincide this with an auxillery water pump that isswitched on when say your head temp reaches 105degrees to sort out the circulation and then maybe a secondary small fan of the rad that also kicks in maybe this will solve all of your problems but again its only my opinion :)
 
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pulsarboby

Guest
the temp senders already located at the rear of the head though (not on block)

but fair point with regard to charge cooler, a few more pounds isnt gonna make a great deal of difference if i can run at 1.5 bar which would put car around 380-390bhp

definately seems that everyones in favour of electric pump though over underdrive pulley.
 

Trip

New Member
This is maybe bollocks, but can the radiator of the charge cooler sit at the rear instead of the original backbox. This will put the weight at the back.
 

takumigtir

New Member
bob just out of interest what pulley do you use to underdrive your waterpump is it possibly off a sr20ve or sr16ve which has a higher power band by any chance ???? and have you had any problems at lower engine speeds using it?if you dont want to broadcast it thats fair enough :thumbsup:
 
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pulsarboby

Guest
its a gsport pulley which was ordered from the states, around 10mm bigger radius over standard.

in all fairness the cars never really at low speed or idling for any period of time so cant really answer that question but ive had no probs with it and it does definately help with cooling when cars flat out, but only upto around 350bhp once you step over that line then temps start to rise again.
but as i said previously....the car was detting its tits off last time out so to be fair the temps are gonna rise through the roof.
il find out for sure next week (if my lashup engine runs that is) at brands hatch because thats one circuit which is very tough on a car with constant gear changing the cars under a lot of stress there especially if its a hot day.
 

gtirx2

Active Member
Do you know what size belt you are using with the gspec pulley Bob?

Also here is a couple of pics i saved from when looking for information about big bore kits.
Think it was in a for sale ad on the sr20 forum and i think he had the work done by mazworks?



 
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pulsarboby

Guest
same size belt rich, theres enough adjustment to take the bigger pulley.
that block looks interesting seems as though the waterways have been opened up on that aswell
 

Matt Evans

Member
Looks like the water ways have channels running between them. Would that effect the water circulation in any way?
 
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pulsarboby

Guest
theres nothing you can really do regarding the channeling unless you have some kind of very small flexible dremmel on a wire.
im sure something probably does exist but ive not got one, im sure just opening up the galleries slightly and matching them to the head will help a lot.
 

Matt Evans

Member
What I meant bob is there seems to be a shallow groove ground out running between and connecting to each water channel. I'm sure its not like that as standard, is it?
 
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