BlownCorona

BlownCoronas 1971 Toyota Corona

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its a different conversation and potentially worth its own thread?

but is there any reliable way to implement decent knock detection without buying high end professional gear? 

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Re your CR issue,

Might pay to see if anyone makes a "head saver shim". ACL used to make them for Datsun A series motors. They're meant to be used to drop the CR after you've had the head skimmed too much/too many times. They came in .030, and .060. (.75 and 1.5mm) 

They do rape your squish/quench though. 

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They are availible for manufacture. And given I'm standing right next to a cnc mill, I could probably make one myself. 

But unsure on their performance with sealant on one side and a std gasket on the other? 

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knock detection is easy enough.    I just use a donut style sensor and a small audio amp and headphones.      Think it was  old mate @Roman dave? that was using laptop mic input then headphones out to do similar thing, via some software.    i kinda like the amp idea since aren't changing from analog to digital back to analog. but may not be an issue. 
biggest thing is knowing what your listening for.  some engines with noisy valvetrain it can be a pain in the ass to catch it early.   quiet engines are easy.

using the ecu to detect knock can be done, but is a pain in the ass to setup and alot of them suffer from false alarms.   you pretty much need to knock the engine to set it up also.

if your octane/knock limited best to go the audio way.  advance timing till  have  light knock. then back it off 2-3 degrees.  thats your timing number.      

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Perfect, this is exactly what I was going to do. 

Have a good quality donut type sensor and was going to feed it into the laptop microphone. 

But I've also been wanting a small headphone amp for my desk at work so perhaps a chance to double down on some investment. 

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Yeah the laptop trick works well, but you need to setup your laptop to have a direct pass through from input to output.

So it basically goes Input > amp > output otherwise its too laggy if it needs to go through any processing on the laptop. 

Cant remember how to do that but its somewhere in the settings for the mic jack I think.
 

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Had to go do stuff... 

Re fuel,  compression ratios etc.  Probabaly noticed have been avioding giving a straight answer; Because to many variables.   95 probably ok going by what you have said. Should be tuneable. But wouldnt expect to get the most out of it. 

Same reasons haven't  posted to many examples. My 4age have run 11.5 compression  on 11psi (turbo) with 98 fuel. But different engine and to many variables to compare. 

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100% understand you can't give a definitive answer,its not even a common engine let alone a common modification to it. 

I'm super grateful for any pointers and prior experience ect. 

 

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Heard back from L C Engineering and they piston kit is indeed availible, so I'll be looking to order this in the next day or so. 

Hopeing I can get it shipped to the American division of my work, and get it drug muled back under the cover of darkness! 

Cheers for the help this far. I'm sure that's not the end of my problems! 

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On 09/10/2019 at 15:16, BlownCorona said:

 

But unsure on their performance with sealant on one side and a std gasket on the other? 

I ran them on a number of engines. Copper head gasket cement between the block and the shim, and a permaseal head gasket on the other. Ran up to one bar of boost. I did suffer s few failures, but they were all detonation related. (Shit fuel, and too much boost/heat)

My last engine now has a turbo on it, and is going strong in it's new life.

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fair enough. im gonna go with the 20R piston kit though. off the shelf parts that dont cost the moon that land me right where i want to be for not too much money seems like the good option, they are an aftermarket kit from a company in the states that specalises in building performance 20/22Rs and states the kits are suitable for mild boost. 

my only real question now is whether i keep the supercharger setup, and run a bypass so i can keep load off the engine at low RPM. as i do wonder if thats what contributed to blowing the first headgasket? though i suspect it was just and engine rebuilt poorly and/or neglected as i know it was sitting in a feild for upwards of 5 years. 

or do i convert to a turbo setup. if i did go turbo id want it to look very retro style, with an old looking (not nessesarly, or idealy acually old though), a bit old finned HKS external wastegate ect. hopefully that kind of paints the picture of the style setup id be interested in. 

 

ultimately its the same core engine and i can decide later on, i think im leaning towards keeping it supercharged. but having a supercharged car, a turbo car and v8 car wouldnt be the worst thing in the world

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should be fine either way, with the engine you're planning.    worst case you will just need to step up to better fuel.  tuning with knock detection  is key.

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oh thats not a decision based on anything other than what id like to own and the different obnoxious noises they can make which are a massive guilty pleasure lol. 

good fuel and knock detection are definitely happening. 

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Can run one of these as an option for bypassing the SC at Idle, another option is running a wastegate in reverse or having a TB open via a vac solenoid. I have also been thinking about a DBW TB to be ecu controlled as a bypass as well (can also tune this or the wastgate to bleed off boost as well) 

https://www.golebysparts.com.au/collections/turbosmart-blow-off-valves/products/race-port-supercharged-applications-black-ts-0204-1107

 

Wastegate wise I would just get a generic ebay one disassemble to remove swaft and reassemble with locktite etc should be fine for the application

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holy shit thats expensive :P what am i, rich? 

but unfortunately that wont work in my setup, my throttlebody is before the blower, so i need a path around the blower, not something that bleeds off its pressure. 

essentially an electric valve. i can actually run the engine with the blower turned off and the engine will suck its air throught the blower spinning the lobes. but i dont know how back for fuel economy that kind of intake restriction would be. guessing pretty significant

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13 hours ago, BlownCorona said:

fair enough. im gonna go with the 20R piston kit though. off the shelf parts that dont cost the moon that land me right where i want to be for not too much money seems like the good option, they are an aftermarket kit from a company in the states that specalises in building performance 20/22Rs and states the kits are suitable for mild boost. 

my only real question now is whether i keep the supercharger setup, and run a bypass so i can keep load off the engine at low RPM. as i do wonder if thats what contributed to blowing the first headgasket? though i suspect it was just and engine rebuilt poorly and/or neglected as i know it was sitting in a feild for upwards of 5 years. 

or do i convert to a turbo setup. if i did go turbo id want it to look very retro style, with an old looking (not nessesarly, or idealy acually old though), a bit old finned HKS external wastegate ect. hopefully that kind of paints the picture of the style setup id be interested in. 

 

ultimately its the same core engine and i can decide later on, i think im leaning towards keeping it supercharged. but having a supercharged car, a turbo car and v8 car wouldnt be the worst thing in the world

Every factory PD blower I’ve seen runs a bypass. Comy v6 tun a small 25mm one built into the housing. Toyota run an external plastic one that works as a wastegate effectively.

 

cheap way of doing one is using a late model VW bypass, in their system they use it as a plumb back blow off valve. Can be bought fit around $25 and work perfect

 

 

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my S4 had those and i was seriously considering that as an option. 

for those that dont know, i believe hes talking about the 710N valve on audis and vws. essentially a vacuum/boost operated valve. its quite likely the option ill take i think. 

Image result for diverter valve audi

it would be a really clean way of allowing the air around the blower. 

i put really expensive 034Motorsport billet ones on the S4 and i regret not swapping them out for standard before selling!

 

 

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33 minutes ago, BlownCorona said:

my S4 had those and i was seriously considering that as an option. 

for those that dont know, i believe hes talking about the 710N valve on audis and vws. essentially a vacuum/boost operated valve. its quite likely the option ill take i think. 

Image result for diverter valve audi

it would be a really clean way of allowing the air around the blower. 

i put really expensive 034Motorsport billet ones on the S4 and i regret not swapping them out for standard before selling!

 

 

Yup that the one 

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