Your face and voice and that awesome shirt all had me smiling within the first two seconds :) I love the legitimate use of playdough! The smell of that stuff provides a portal back to childhood memories. Thank you for the brilliant guide and the appropriate warnings for some engine types! I still don't understand a lot of engine stuff but you present the process clearly and simply enough for a novice to repeat it.
Re-cutting valve pockets is a very simple operation. You can even do it at home, although getting depth equal on all pistons is a little bit challenging (not too difficult if your doing a full re-build though) All you need is an old valve with correct stem diameter but head needs to be 1mm~2mm larger. Literally, grind cutting teeth into valve head then spin with an electric drill. It's easier than brazing tool steel to an old valve then grinding cutting angles onto that. You can also use same method to mark where pistons need cutting and have them done in a machine shop although very few shops will have a good method of holding pistons, clamping them in vice works but can easily distort them. I make a holder to locate inside piston skirt then use a drawbar onto piston pin.It makes set up very easy
@Brett Collins They don't always fail, right. especially if you chance any tensioners or guides while you're in there. I've also seen timing belts last well past their lifetime, even if a bit more rare. (pretty sure the one on my 208K focus is original, from how it's looking....yeah that's getting changed soon) Just saying timing chains aren't invincible to failure, not to mention more expensive to produce (multiply by mass production) and require lubrication. Mainly depends on what he engine is used for. V8 truck for hauling or racing? use a chain. Little 1.8L four-banger for getting your groceries and hauling the fam around for thousands of miles? A belt will do the job, and still equal a lighter engine overall, which can be valued for fuel economy.
Man this a great and exciting project!! I wish this project came out in 2016 when I was a teen with a ae91 I sold it because I had no idea what I was doing and wanted something “fast”, now that I have the skill and videos like yours I can’t find any ae91, I will definitely want to try a performance 4afe build like yours
I shaved my heads,higher lift cams and higher comp pistons once. I didn't check ptv. This was back in my early days. I actually got lucky and didn't have an issue.
What a coincidence, the day I'm going to install new cams and check valve clearance is the same day you post this. Mine's an interference motor and it's about .080in clearance, but a word of advice. If you find yourself in a situation where clearances are in the thousands of an inch DO NOT use Play-Doh. When smashed it rebounds a few thousands of an inch. So in my case using Play-Doh would make for a very bad day.
I've watched a lot of your videos and thought they were very good, two things you forgot to take into account though. Conrods stretch at high heat/high RPM, and head bolts also stretch. To be measured accurately, this does need done with the right medium, and you need to factor in the "stretch" of the rod and the head bolts, and how much the piston grows due to thermal expansion (to be fair, both figures are usually minimal but need to be factored in for safety). Just don't want to see any young kid go do this, think they are safe with their "checks", then have their motor blow up because they didn't take something into account. Otherwise, I find all your vids to be very informative, well spoken and presented, keep up the good work
Your videos are amazing and very informative! Thank you, can't wait for more, although I have a few days of videos to watch from your channel still haha
i did this sort of job on a interference engine but instead of play dough, i used a probe camera thru the spark plug hole, its super cool watching the valve almost getting to the piston before the piston retreats down its cave
With the cylinder head in place, melt a candle and with the plug hole uppermost, pour the molten wax down it until the combustion chamber is quite full and the plug hole starts filling. Wait about 20 minutes then remove the cylinder head, carefully remove the solidified wax and put it in a 'fridge to harden. You will then have a precise view of the combustion chamber shape and clearances, which are measurable. Weigh the solidified wax and use it's SG to calculate it's volume, alternatively melt it into a measuring cylinder, taking care not to lose any of it.. Supercharged or turbocharged engines normally have lower compression ratios than normally aspirated ones. As the C R is influenced by the shape of the piston crown, it is questionable if pistons for a supercharged engine will be satisfactory in a normally aspirated one.
This will be turbocharged. The wax approach isn't a bad idea, but it's very fiddly. You could do the same with liquid polyurethane. You couldn't melt it afterwards tho.
@@d4a Rotating camshaft without timing chain/belt? I know it had the disclaimer right after but it instantly triggered my inner "WTF are you doing" voice
Since the higher compression pistons are acceptable, I would go with those, and simply eyebrow the valve relief a little more on the intake side particularly. I'm more a fan of higher compression than I am higher boost, seeing as compression is efficiency. I'd rather hit a higher efficiency 400hp than a lower efficiency 420 horsepower. That's just me tho. Power efficiency is what I desire most.
I am swoping my series 1 piston to series 3 pistons i was told it would be saver to put two head gasket on for the valve clearance? My block got skiemed and my head aswell... But its was still fresh it was only skiemed once
Do you remove your smallport pistons from the mr2? Non interference engine is not a problem with me but is there any other problem other than that? Using smallport piston in a 4afe
If you already answered the question in the video I'm sorry for asking. Are the 20mm wrist pins in the 4afe pressed or fully floating like the later 4age pistons?
Hi, your content is very informative and i love it. Could you please help me with a value clearance query? I have a Mitsubishi pajero gen 2 1998 model with a 4m40 turbo diesel engine. I recently got it rebuilt, replace the head with a brand new one. Everything was replaced with brand new parts but when I check the value clearance with a guage feeler and found out none of them were as per the company specifications which are 0.25mm for inlet 0.35mm for exhaust under warm engine temp. As of now all the value clearances vary slightly from these specified numbers. Could it be a cause of destruction for the engine?
@@d4a okay but if we set it at the company specified specs the tappets would make alot of noise. Right now the engine starts perfectly and there's no missing in the engine but slightly looses power on decent.
I would be more concerned about the extra space from the ge valve cutouts lowering the compression as well as affecting the squish area. Good chance the 4age low compression pistons may lower the compression too much with the 4afe cylinder. 1.6l already being quite torque less combined with no vvti and a low tech decently sized turbo might make the car annoying to drive when off boost 🤔
So I’m Supercharging my 96 corolla 4AFE with a SC12 out of a azge with stock top mount intercooler, at stock boost (for now) would you recommend maybe getting custom forged afe pistons made? I’m looking for 150-200whp
@@d4a In your Iconic Engines #13, around 18:59, you have an image of a guy sitting in a tree using a saw. Maybe you use add-ons or something, but it would take me forever to put together a simple image like that. Anyway, it works for me, love your videos.
Did you lock the crank in place when you did the test? Can you be certain that the opening of the valves did not force the pistons down in the bores a tiny bit?
Nope, didn't lock crank in place. But I rechecked piston height afterwards. No movement. Also, valves are in most cases not able to push the piston down, they would just bend.
The piston dwells at top dead center as the con rod moves from one side to the other of the crank. That’s like trying to turn a door knob by standing on it.
@@d4a Great, just making sure you know. As long as you put the rods straight up the valves would never be able to move the pistons, but even a few degrees could potentially introduce problems.
A very rule of thumb-ish minimum is 2mm on intake and 2.5mm on exhaust. If you plan to rev pretty high or do forced induction a larger safety margin isn't a bad idea, something like 2.5 intake and 3 exhaust.
You can use the 7afe block with 4age 16v crankshaft connecting rods and pistons with 7afe metallic packing. The 4afe and 7afe cylinder heads are the same.
This is not how you check piston to valve clearance. You actually said it - that's just an experiment to see what would happen if the cambelt snaps, but this is not how you check your clearance - you have to do it with the timing belt in place. So this isn't really an instructional video as the title would suggest. Anyways, i watch almost all of your videos and like the content, but in this case i would say that the title is misleading.
Don't use play-doh. It compresses then springs back and will not give you a accurate measurement. A easy find to use is clay bar in the auto parts store in the body detailing section. It holds it's compressed size good
Ikw ima sounds like a noob but I have a blue top 4age on my mr2 is it an interference engine? Cause I have no clue yet how to set the cams on the cylinder head I’m still looking for a big port cylinder head .
I thought every engine is interfernce...good to know. I guess some of the high performance low consumption engines are interference...and the rest are ...nonconflictual ;)
Most modern engines are, but up until the 90s, and in some cases early 2000s, it was not unusual to see non interference engines in mass market cars. For example the 2.0 AQY engine in the Golf IV was non interference and produced until 2003.
That's actually very engine specific. You can't really predict which one is interference or non-interference. Every diesel engine will be one, but petrol engines are very different from eachother, all lays on the way the engineers have designed them. You can guess that low compression ones will be non-interference, while higher compression ones will be interference, but that's still just a guess.
@@ptilrem 2.0HDI is interference engine, just designed to have the levers between camshaft and a valve which break to prevent any damage to pistons and valves themselves.
You need to use pistons engineered for the 4AFE head. You are only checking valve clearance; squish is critical as well to reduce the risk of detonation. If you use the 4AGE pistons, the squish is poor for reasons you shred t the beginning of the video.
All the more important. Compression ratio, valve to piston clearance, and squish are all important. The reported compression ratios are incorrect if the pistons from a 4AGE are used with a 4AFE head. And the 4AGZE pistons result in a very low compression ratio even on the 4AGZE. Modern engine management makes running a low compression ratio on a turbocharged engine obsolete.
@@moocow2172 indeed if your not using a good ecu witch he is so it should be just fine with high comp pistons but ya if he wasn't using a aftermarket ecu it wouldn't work well at all
@@tupacisthebomb23 it's not to do with ecu it's to do with the octane rating of the fuel, the temperature of the engine and reliability and safety, high boost engines run lower comp so they can run that high boost with less risk of knock, boosted production cars run less comp You could run high comp and high boost on a re-mapped stock ECU?? with less reliabilty and power than a lower comp higher boost setup and with more cost. Watch a few more vids and get back to me all the higher comp will do in reality is give better response off boost, which is not where we intend to make changes on a turbo car....
Its an engineering preference for failure modes which don't cause secondary damage. A bolt holding an engine mount may fail causing an annoying driveline vibration. Or it may fail and then fall into the path of the cam belt teeth and destroy the valves. Or it may fail and drop into a position where it blocks a critical oil return. Or it may fail by breaking into small fragments that get ingested into the oil feed. Same 10c bolt and the best case scenario is it costs 10 c to rectify the failure and worse case scenario is its repair cost exceeds the value of the car. An engineer will look at every failure mode and act if he's not satisfied with the outcome. Think of every time a factory service manual has a routine task with the bold type heading "failure to do this exactly as directed will result in catastrophic damage". Why design in that level of risk if there's a no cost alternative?
@@stephenbello1081 Let's say you have a semi serious engine. Make pockets for valves that have say 2mm TDC lift, with some room to spare. OR, make deep enough pockets for the whole 12mm of lift you have. Either your pistons are far off the head (low comp) or the valve pockets are pretty damn deep. Can you make them that deep safely? How much worse did the combustion chamber shape become? Did you create hot spots to the pistons? How much did you lower the compression by making extra 10mm depth to the valve pockets? That by the way is a non trivial number of cc's. Not here to be wiser than thou or put anyone down. I have actually had to work on engines a bit and have stood in the pits as a mechanic. My thoughts come from personal experience.
Become a Tuning Pro: hpcdmy.co/dr4a
Support the channel by shopping through this link: amzn.to/3RIqU0u
Patreon: www.patreon.com/d4a
You just wanted an excuse to play with Play-Doh as an adult. 😏 Nice job!
You got me 😉
Your face and voice and that awesome shirt all had me smiling within the first two seconds :) I love the legitimate use of playdough! The smell of that stuff provides a portal back to childhood memories. Thank you for the brilliant guide and the appropriate warnings for some engine types! I still don't understand a lot of engine stuff but you present the process clearly and simply enough for a novice to repeat it.
Re-cutting valve pockets is a very simple operation.
You can even do it at home, although getting depth equal on all pistons is a little bit challenging (not too difficult if your doing a full re-build though)
All you need is an old valve with correct stem diameter but head needs to be 1mm~2mm larger. Literally, grind cutting teeth into valve head then spin with an electric drill. It's easier than brazing tool steel to an old valve then grinding cutting angles onto that.
You can also use same method to mark where pistons need cutting and have them done in a machine shop although very few shops will have a good method of holding pistons, clamping them in vice works but can easily distort them. I make a holder to locate inside piston skirt then use a drawbar onto piston pin.It makes set up very easy
Awesome! Im currently build my first race engine and you ALWAYS give me the content i need.
timing belt *breaks*
valve :
Piston:
now kiss
By kiss you mean someone grabbing a hand full of hair and smashing your face against a rock.
@Brett Collins Til the tensioner lets go. Happened to my friends' explorer recently.
@Brett Collins Timing chain tensioners do exist, ya know.
@Brett Collins both chains and belt use tensioner
@Brett Collins They don't always fail, right. especially if you chance any tensioners or guides while you're in there. I've also seen timing belts last well past their lifetime, even if a bit more rare. (pretty sure the one on my 208K focus is original, from how it's looking....yeah that's getting changed soon) Just saying timing chains aren't invincible to failure, not to mention more expensive to produce (multiply by mass production) and require lubrication. Mainly depends on what he engine is used for. V8 truck for hauling or racing? use a chain. Little 1.8L four-banger for getting your groceries and hauling the fam around for thousands of miles? A belt will do the job, and still equal a lighter engine overall, which can be valued for fuel economy.
Man this a great and exciting project!! I wish this project came out in 2016 when I was a teen with a ae91 I sold it because I had no idea what I was doing and wanted something “fast”, now that I have the skill and videos like yours I can’t find any ae91, I will definitely want to try a performance 4afe build like yours
7afe maybe lol
This is one of the most useful videos on your channel....
And that's already a high bar
i watched this video yesterday and tonight i dreamt of checking piston to valve clearance...
You could also use checker springs on your heads, and different sized shims between the cam/rocker to valve butt
I shaved my heads,higher lift cams and higher comp pistons once. I didn't check ptv. This was back in my early days. I actually got lucky and didn't have an issue.
When you were opening the PlayDoh, l was thinking of smelling it myself if l were you. And you did just that. Nice.
What a coincidence, the day I'm going to install new cams and check valve clearance is the same day you post this. Mine's an interference motor and it's about .080in clearance, but a word of advice. If you find yourself in a situation where clearances are in the thousands of an inch DO NOT use Play-Doh. When smashed it rebounds a few thousands of an inch. So in my case using Play-Doh would make for a very bad day.
Great explanation, very clearly explained. I'm really enjoying this engine swap/build project. Thanks for the extremely well detailed videos.
I've watched a lot of your videos and thought they were very good, two things you forgot to take into account though. Conrods stretch at high heat/high RPM, and head bolts also stretch. To be measured accurately, this does need done with the right medium, and you need to factor in the "stretch" of the rod and the head bolts, and how much the piston grows due to thermal expansion (to be fair, both figures are usually minimal but need to be factored in for safety).
Just don't want to see any young kid go do this, think they are safe with their "checks", then have their motor blow up because they didn't take something into account. Otherwise, I find all your vids to be very informative, well spoken and presented, keep up the good work
You earn a sub ! I have a corolla 97 with a 4afe with a vent valve that I want to rebuilt and turbo so the motivation begins and the trucks for it.
what a great idea, simple methods are often the best. thanks for sharing man
VERY well illustrated and great presentation! Thanks for sharing!
This is pure knowledge. Keep those videos going!
Your videos are amazing and very informative! Thank you, can't wait for more, although I have a few days of videos to watch from your channel still haha
I’m seriously considering pulling the engine out of my 92 geo prizm and do the same thing after watching this.
Awesome video again. Hope you’re doing well during the pandemic
Doing ok! Hope you're well too
I don't even own a car nor know how to drive, but I want to build my own project in the near future too.
thank you man you make my day best day ever
couldn't watch, hypnotized by shirt :D
Good info as always!!!
Me too!
Who are the characters on his shirt?
@@flyonbyya Street Fighter II
Thank u. Greetings from Sweden.
i did this sort of job on a interference engine but instead of play dough, i used a probe camera thru the spark plug hole, its super cool watching the valve almost getting to the piston before the piston retreats down its cave
Love watching your videos very helpful tips I will be using many for my 9agze build
I'm really enjoying the videos, thank you for making them!
Thank u so much for the explanation bro.
Really good stuff man! Dropping a comment to help out the algorithm.
OH MY GOD! You commented on almost every video I made recently. Thank you!
Awsm....explanation...keep it going...brooo..!!! Lots of love and support frm India...
With the cylinder head in place, melt a candle and with the plug hole uppermost, pour the molten wax down it until the combustion chamber is quite full and the plug hole starts filling. Wait about 20 minutes then remove the cylinder head, carefully remove the solidified wax and put it in a 'fridge to harden. You will then have a precise view of the combustion chamber shape and clearances, which are measurable. Weigh the solidified wax and use it's SG to calculate it's volume, alternatively melt it into a measuring cylinder, taking care not to lose any of it..
Supercharged or turbocharged engines normally have lower compression ratios than normally aspirated ones. As the C R is influenced by the shape of the piston crown, it is questionable if pistons for a supercharged engine will be satisfactory in a normally aspirated one.
This will be turbocharged. The wax approach isn't a bad idea, but it's very fiddly. You could do the same with liquid polyurethane. You couldn't melt it afterwards tho.
Awesome explanation.
cant wait to see this thing run #projectunderdog!
Quick and easy to understand thanks man
Thay do, do a early 4AGE a piston with a slight dish in it some of the first AE82
Your video i awsome! I have learned so much!
The kweblkop of mechanics
Suggestion for a video: Explanation of piston squish.
Yes!
Great video!
4:52 I got instant mini heart attack when I saw what he was doing.
?
@@d4a Rotating camshaft without timing chain/belt?
I know it had the disclaimer right after but it instantly triggered my inner "WTF are you doing" voice
Since the higher compression pistons are acceptable, I would go with those, and simply eyebrow the valve relief a little more on the intake side particularly. I'm more a fan of higher compression than I am higher boost, seeing as compression is efficiency. I'd rather hit a higher efficiency 400hp than a lower efficiency 420 horsepower. That's just me tho. Power efficiency is what I desire most.
Nice video content very informative thanks
Thanks for the video man! I got question tho. Whats the inteference/ non inteference engine mean?
Can you make a video about piston pins and con rods small ends?
Great content over here 👈 keep going
very nice
5:10 I was about to say 😬
Quick question, where did you get the pistons from?
Nice shirt, tho bro!! Street fighter!
I am swoping my series 1 piston to series 3 pistons i was told it would be saver to put two head gasket on for the valve clearance? My block got skiemed and my head aswell... But its was still fresh it was only skiemed once
What you think about turboing a 5afe engine
What if you put 4age itbs on the 4afe? Will that improve flow?
I use soft solder.
Quick knowledge
Non-Interference and Interference is a different words for VVT and Non-VVT engine
Not always. You can have non-VVT engines that are interference engines.
would a 4AGE piston work just as well for this build instead of the 4AGZE?
Do you remove your smallport pistons from the mr2? Non interference engine is not a problem with me but is there any other problem other than that? Using smallport piston in a 4afe
If you already answered the question in the video I'm sorry for asking. Are the 20mm wrist pins in the 4afe pressed or fully floating like the later 4age pistons?
Pressed like in older 4ag
@@d4a could you convert to floating?
Hi, your content is very informative and i love it. Could you please help me with a value clearance query?
I have a Mitsubishi pajero gen 2 1998 model with a 4m40 turbo diesel engine.
I recently got it rebuilt, replace the head with a brand new one. Everything was replaced with brand new parts but when I check the value clearance with a guage feeler and found out none of them were as per the company specifications which are
0.25mm for inlet
0.35mm for exhaust under warm engine temp.
As of now all the value clearances vary slightly from these specified numbers.
Could it be a cause of destruction for the engine?
It can't destroy the engine but it might increase wear and noise
@@d4a okay but if we set it at the company specified specs the tappets would make alot of noise. Right now the engine starts perfectly and there's no missing in the engine but slightly looses power on decent.
Hey, when can we expect the next Project Underdog Video ? 👍🏻
Very soon I promise
Are you going to change the cams?
I would be more concerned about the extra space from the ge valve cutouts lowering the compression as well as affecting the squish area. Good chance the 4age low compression pistons may lower the compression too much with the 4afe cylinder. 1.6l already being quite torque less combined with no vvti and a low tech decently sized turbo might make the car annoying to drive when off boost 🤔
The 4AFE has smaller combustion chambers than the 4age. The low comp 4agze pistons actually result in a 9.5 or so static compression ratio in a 4afe.
Sniff* ahhh.... childhood! 🤣👌
So I’m Supercharging my 96 corolla 4AFE with a SC12 out of a azge with stock top mount intercooler, at stock boost (for now) would you recommend maybe getting custom forged afe pistons made? I’m looking for 150-200whp
I'd like to know the software you use for your graphics. Images look fantastic on all your videos.
You're kidding right? The graphics are really amateur-ish. I use paint.net to draw 😊 and premiere pro to edit
@@d4a Cool. Well, I like them. I also use Paint.NET for images, but don't have any video-editing software. I do make lots of animated GIFs, though!
@@d4a In your Iconic Engines #13, around 18:59, you have an image of a guy sitting in a tree using a saw. Maybe you use add-ons or something, but it would take me forever to put together a simple image like that. Anyway, it works for me, love your videos.
Did you lock the crank in place when you did the test? Can you be certain that the opening of the valves did not force the pistons down in the bores a tiny bit?
Nope, didn't lock crank in place. But I rechecked piston height afterwards. No movement. Also, valves are in most cases not able to push the piston down, they would just bend.
The piston dwells at top dead center as the con rod moves from one side to the other of the crank.
That’s like trying to turn a door knob by standing on it.
@@fastinradfordable Exactly!
@@d4a Great, just making sure you know. As long as you put the rods straight up the valves would never be able to move the pistons, but even a few degrees could potentially introduce problems.
Hello! Do you know your engine deck height specs? I went rogue and did manual surfacing ... And I don't know if I went too much
Is there any engineering data that specifies general or specific clearance minimums for this motor?
A very rule of thumb-ish minimum is 2mm on intake and 2.5mm on exhaust. If you plan to rev pretty high or do forced induction a larger safety margin isn't a bad idea, something like 2.5 intake and 3 exhaust.
Quick question can I swoop my 7AFE engine head for a 4AGE hea
From the sounds of it no different valve angles
You can use the 7afe block with 4age 16v crankshaft connecting rods and pistons with 7afe metallic packing.
The 4afe and 7afe cylinder heads are the same.
What is high compression pistons and what are low compression pistons and how can you tell them apart
Lower comp pistons will always have more dish
How much horse power do you think you can make with the same internals and no turbo... plz thank u
The low comp pistons fits to the maxpeeding rods?
Yup
This is awesome : )
This is not how you check piston to valve clearance. You actually said it - that's just an experiment to see what would happen if the cambelt snaps, but this is not how you check your clearance - you have to do it with the timing belt in place. So this isn't really an instructional video as the title would suggest. Anyways, i watch almost all of your videos and like the content, but in this case i would say that the title is misleading.
Don't use play-doh. It compresses then springs back and will not give you a accurate measurement. A easy find to use is clay bar in the auto parts store in the body detailing section. It holds it's compressed size good
That's definitely a shirt ;)
Ikw ima sounds like a noob but I have a blue top 4age on my mr2 is it an interference engine? Cause I have no clue yet how to set the cams on the cylinder head I’m still looking for a big port cylinder head .
Why that engine block is still so dirt?
I use this trick years ago but I used plasticine
Am i the only one wandering what would've happened if soneone leves playdough inside engine and fire it up ?
Great video btw ;)
Now I'm curious too 😂
You should tip Project Farm about that I think.
@@ptilrem good point
@@ptilrem or *our* Russian friends at Garage54, but Lada engines might not care.
Holy overexposed, Batman! (Still amazing content though)
Yeah.. I need a better camera
Let's hope this doesn't take as long as Binky.
Great video but I hate interference engines
With horses comes problems..
4:19 Clay left in the gasket area. No good.
Anyone else hear the truck passing sound or whatever at 2:12?
Now do it for the 5 valve head...
I thought every engine is interfernce...good to know. I guess some of the high performance low consumption engines are interference...and the rest are ...nonconflictual ;)
Most modern engines are, but up until the 90s, and in some cases early 2000s, it was not unusual to see non interference engines in mass market cars.
For example the 2.0 AQY engine in the Golf IV was non interference and produced until 2003.
That's actually very engine specific. You can't really predict which one is interference or non-interference. Every diesel engine will be one, but petrol engines are very different from eachother, all lays on the way the engineers have designed them. You can guess that low compression ones will be non-interference, while higher compression ones will be interference, but that's still just a guess.
@@XStuntManiac I had the cambelt snap on a 2.0HDI from 2004 several years back. No damage on the engine.
@@ptilrem 2.0HDI is interference engine, just designed to have the levers between camshaft and a valve which break to prevent any damage to pistons and valves themselves.
@@ptilrem It isn't always fatal for interference engines. Unless you are on a fast road and somebody hits you.
under 100 view gang where u at?
Easy if engine is out
You need to use pistons engineered for the 4AFE head. You are only checking valve clearance; squish is critical as well to reduce the risk of detonation. If you use the 4AGE pistons, the squish is poor for reasons you shred t the beginning of the video.
Turbo
All the more important. Compression ratio, valve to piston clearance, and squish are all important. The reported compression ratios are incorrect if the pistons from a 4AGE are used with a 4AFE head. And the 4AGZE pistons result in a very low compression ratio even on the 4AGZE. Modern engine management makes running a low compression ratio on a turbocharged engine obsolete.
Why not use the stock pistons with higher comp ? More power na makes better turbo power
higher comp = increased chance of knock wih less boost??
@@moocow2172 indeed if your not using a good ecu witch he is so it should be just fine with high comp pistons but ya if he wasn't using a aftermarket ecu it wouldn't work well at all
@@tupacisthebomb23 it's not to do with ecu it's to do with the octane rating of the fuel, the temperature of the engine and reliability and safety, high boost engines run lower comp so they can run that high boost with less risk of knock, boosted production cars run less comp
You could run high comp and high boost on a re-mapped stock ECU?? with less reliabilty and power than a lower comp higher boost setup and with more cost.
Watch a few more vids and get back to me all the higher comp will do in reality is give better response off boost, which is not where we intend to make changes on a turbo car....
You don’t have to lube the piston
Would have thought any engine with cut outs in the pistons would be interference. Evidently not.
Well some high comp engines have them to allow for a sharper lift cam. And low comp to make it non interferece.
Well.. not really relevant unless the pistons actually have tdc att deck.. most turbo conversions dont...
Why not just use a cheap usb endoscopic camera with a mirror down the spark plug hole ?.
Why should one aim to build a non interfering valvetrain/pistons? I see no reason to.
Its an engineering preference for failure modes which don't cause secondary damage. A bolt holding an engine mount may fail causing an annoying driveline vibration. Or it may fail and then fall into the path of the cam belt teeth and destroy the valves. Or it may fail and drop into a position where it blocks a critical oil return. Or it may fail by breaking into small fragments that get ingested into the oil feed. Same 10c bolt and the best case scenario is it costs 10 c to rectify the failure and worse case scenario is its repair cost exceeds the value of the car. An engineer will look at every failure mode and act if he's not satisfied with the outcome. Think of every time a factory service manual has a routine task with the bold type heading "failure to do this exactly as directed will result in catastrophic damage". Why design in that level of risk if there's a no cost alternative?
@@stephenbello1081 it is NOT a no cost alternative. Planning for failure is planning to fail
I now see the reason why "you see no reason to".
@@stephenbello1081 Let's say you have a semi serious engine. Make pockets for valves that have say 2mm TDC lift, with some room to spare. OR, make deep enough pockets for the whole 12mm of lift you have. Either your pistons are far off the head (low comp) or the valve pockets are pretty damn deep. Can you make them that deep safely? How much worse did the combustion chamber shape become? Did you create hot spots to the pistons? How much did you lower the compression by making extra 10mm depth to the valve pockets? That by the way is a non trivial number of cc's. Not here to be wiser than thou or put anyone down. I have actually had to work on engines a bit and have stood in the pits as a mechanic. My thoughts come from personal experience.
Children. Subaru is interference.
Firstt...
tid[