Jump to content
SAU Community

Recommended Posts

Hi all,

As you've probably guessed by the title, my car had a heart attack ( oil surge = main bearings go knock, knock ). :D

Anyway, I have a couple of questions for you all that I hope you can help me with. PLEASE keep the answers kinda serious because I need good info quickly.

1. Has anyone used "Pro Flow" located out west of Sydney to build their engine, head work etc ?? Opinions please because I'm considering using their services.

2. Forged Pistons. Looking at "Arias" pistons. Opinions please ?

3. Sump Baffles/Anti-Surge trap doors etc. Best option, who, where, how much etc please ?

4. Anything you think might be relevant while engine is out ?

Thanx :D

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/
Share on other sites

can i ask what the cause of the oil surge was?

If it was launching hard what sort of power are you putting out?

i am concerned because my car squats like a hoe and i dont want that to casue any oil starvation problems with increased power.

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-559713
Share on other sites

Fast31,

Thanks for the feedback. So far so good with my current direction.

Skyrine-Dave,

Track work ! Did it at Eastern Creek either through turn 1 at over 200kph or under brakes leading into turn 2. Not sure which and I guess it doesn't matter. I'm only putting out around 200rwkw.

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-560605
Share on other sites

I'd keep the CR standard 8.5:1 and do as much head work as you can afford. Maybe at the same time slap in a set of NA cam's or even better a decent set of aftermarket cams but that may blow the budget out.

Stroke it out to 2.3ltrs, Look in to using the RB25 conrods/crank, not sure exactly what has to be done.

Baffle the sump. :D

Not sure if you really need or want the motor to be blueprinted.

O-Ringed block and standard head gasket. From memory O-ring is a roughly $33 per cyclinder.

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-560689
Share on other sites

Ah Joel,

If only I had the money.......

I'm just going to fix up the bottom end, put a set of forgies in, get the sump baffled, get the head serviced and some mild porting including match porting the manifolds to the head.

Can't afford to go the stroker and play with cams ect :D

So is the CR 8.5:1 for sure ?? Will help to know this when I go for a head gasket. Not sure if I want to raise the CR slightly and use less boost or continue with 18psi and keep the CR lower or standard.

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-562375
Share on other sites

18psi will be the maximum I would wont to run with a 9:1 cr and a good tune.

Are you going to clean up the head a little?

VRS kits are around $270 which include valve stem seals.

If anything port match the manifold and inlet ports. (Its easy)

and remove the bumps from the exhaust ports.

Depends if you are willing to do bits your self. :D

Stroker would be nice if you came across a cheap stuffed RB25, bring boost on earlier and make more torque when you are on boost :D

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-562384
Share on other sites

Joel,

Yes I'm going to get the head fully serviced, match ported and some minor port polishing. If I do bring the CR up to around 9.1:1 I'll only be running around 16psi boost. I should still get 200rwkw and that's all I need. ( I must be getting old to say sh!t like that ).

Excuse my ignorance but VRS Kit ?? Where does one get one of these to suit an RB20DET ? ( assuming that I'm going to need one ).

If I knew exactly what was invloved in building it into a stroker I probably would but all my engine building knowledge and experience is back in the days when I used to play with my BDA Cosworth Escort. God, I am old!

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-563500
Share on other sites

This sounds familiar, but i still havent had the courage to take my car to a mechanic to find out if the slight cold start knock is my bottom end.

Still has good oil pressure, drives A1 and 20sec after start no noise so i am still living in hope.

Looking at the power you have, and the power you will be happy having, i would consider buying a low kms import engine. With some DIY work you can have the new engine in for les then the cost of forged pistons.

If it turns out the knock is someting terminal in my engine, my heart tells me rebuild with some good internals, but commonsense tells me at the power i will have the expense isnt justified.

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-564859
Share on other sites

Fast31. The simple answer is......so it will last !

Roy, I hear what you're saying and I've had that argument with myself a hundred times but considering what I use this car for ( primarily track days ) I don't want to go through this down time again and at least I'll know what my engine is likely to do whereas a 2nd hand engine is only as good as the last person who neglected or thrashed the arse out of it. I guess the methodology is that a better than stock engine will give the same power with less stress than a stocker.

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-566541
Share on other sites

The more headwork the better. You get more airflow for any given psi. Remember PSI is the actual restriction to air flow.

So reduce that restriction and you get x amount of air in to the pots on less boost. So basically it will make the same power on less boost which gives you more head room and allows you at the end of the day to make more power.

I wouldn't bother with pistons. Keep the stockers.

The RB20 isn't going to make power where it needs them. i.e over 250rwkw.

Spend the money on some major head work.

It will also spool the turbo up quicker.

The VRS kit is a Valve Regrind Kit. It comes with a Headgasket, Cam oil seals, valve stem seals (required for head rebuild), rocker cover gaskets, inlet manifold gasket, exhaust manifold gasket, plenum gaskets. Thats about it I think.. Its a must and its the cheapest way to get out of buying the gaskets individually.

They are around $275. The Genuine Nissan head gasket on its own is around $75. If you buy the valve stem seals on their own they are around $300. So you would have to be stupid to buy the parts seperately.

O-Ring the block with the standard head gasket is the best way to go about things if you want to run high boost. Unless you want to buy a big $$ HKS head gasket that has the O-ring built in.

But If you are only going to be running up to 1.1-1.2bar then I wouldn't worry about O-ringing or HKS head gaskets. Stick with the OEM head gasket as they are very good.

Also when running high boosts, if you havn't got a good seal from not O-ringing the combustion chamber gases can some times seep in to your coolant galleries in turn boiling the coolant easier which will apear as the car starts to overheat for no reason. Not 100% sure on that last one but thats the way i understand it.

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-566580
Share on other sites

"This sounds familiar, but i still havent had the courage to take my car to a mechanic to find out if the slight cold start knock is my bottom end.

Still has good oil pressure, drives A1 and 20sec after start no noise so i am still living in hope. "

Now i'm worried about my car (R32 GTS-t)... I did an ECU fault test the other week, and saw that the Knock Sensor was coming up. When the car is cold, it is very hard to start (have to pump accelerator repeatedly) and the oil pressure sits under 4 on the dash nearly at all times... Does this mean i've done a main bearing, blown the bottom end or am i just paranoid?

I'm not exactly a wizz at this whole mechanical side of life, so can anyone please explain to me what is wrong, if anything?

Thanks. Matt.

Link to comment
https://www.sau.com.au/forums/topic/26435-rb20det-rebuild/#findComment-567689
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Lucky man, who owns it in the family? Any pics? 
    • The engine stuff is Greg Autism to the Max. I contacted Tony Mamo previously from AFR who went off to make his own company to further refine AFR heads. He is a wizard in US LS world. Pretty much the best person on earth who will sell you things he's done weird wizard magic to. The cam spec is not too different. I have a 232/234 .600/603 lift, 114LSA cam currently. The new one is 227/233 .638 .634. The 1.8 ratio roller rockers will effectively push this cam into the ~.670 range. These also get Mamo'ified to be drilled out and tapped to use a 10mm bolt over an 8mm for better stability. This is what lead to the cam being specced. The plan is to run it to 6800. (6600 currently). The Johnson lifters are to maintain proper lift at heavy use which is something the LS7's supposedly fail at and lose a bit of pressure, robbing you of lift at higher RPM. Hollow stem valves for better, well everything, Valve train control. I dunno. Hollow is better. The valves are also not on a standard valve angle. Compression ratio is going from 10.6 to 11.3. The cam is smaller, but also not really... The cam was specced when I generated a chart where I counted the frames of a lap video I had and noted how much of the time in % I spent at what RPM while on track at Sandown. The current cam/heads are a bit mismatched, the standard LS1 heads are the restriction to power, which is why everyone CNC's them to get a pretty solid improvement. Most of the difference between LS1->LS2->LS3 is really just better stock heads. The current cam is falling over about 600rpm earlier than it 'should' given the rest of my current setup. CNC'ing heads closes the gap with regards to heads. Aftermarket heads eliminate the gap and go further. The MMS heads go even further than that, and the heads I have in the box could quite easily be bolted to a 7.0 427ci or 454 and not be any restriction at all. Tony Mamo previously worked with AFR, designed new heads from scratch then eventually founded his own business. There he takes the AFR items and performs further wizardry, CNC'ing them and then manually porting the result. He also ports the FAST102 composite manifold: Before and after There's also an improved racing crank scraper and windage tray. Helps to keep oil in the pan. Supposedly gains 2% power. Tony also ports Melling oil pumps, so you get more oil pressure down low at idle, and the same as what you want up top thanks to a suitable relief spring. There's also the timing chain kit with a Torrington bearing to make sure the cam doesn't have any thrust. Yes I'll post a before and after when it all eventually goes together. It'll probably make 2kw more than a setup that would be $15,000 cheaper :p
    • Because the cars wheels are on blocks, you slide under the car.   Pretty much all the bolts you touched should have been put in, but not fully torque up.   Back them off a turn or two, and then tighten them up from under the car with the wheels sitting on the blocks holding car up in the air.
    • Yes. Imagine you have the car on the ground, and you mine away all the ground under and around it, except for the area directly under each individual wheel. That's exactly how it'd look, except the ground will be what ever you make the bit under each wheel from
    • Yes, if you set the "height" right so that it's basically where it would be when sitting on the wheel. It's actually exactly how I tighten bolts that need to be done that way. However....urethane bushes do NOT need to be done that way. The bush slides on both the inner and outer. It's only rubber bushes that are bonded to the outer that need to be clamped to the crush tube in the "home" position. And my car is so full of sphericals now that I have very few that I need to do properly and I sometimes forget and have to go back and fix it afterwards!
×
×
  • Create New...