E55 Engine Rebuild - Part 3 (Machining Pistons & Ring End Gaps)

[@Conservator.]

I’ll probably never rebuild an engine but I find your video’s fascinating. Love how you show all those details on your rebuild and explain the choices that you make. Thank you! 👏

[@MirchiBoy]

You answered every question I was thinking of as I was watching the video. Just awesome!!!

[@tischlerbmw21]

One thing I recommend is chamfering the inside of the oil holes on the pistons, so the oil will flow better

[@generation4523]

Love all the content and have followed your channel for a couple months since your e55 broke. Glad to see that you aren't giving up on it! You deserve many more views and I'm sure you'll get them if you keep uploading the amazing content

[@ttiization]

The fact that you believe in the precision of a Chinese bench milling machine is outstanding

[@extremguzey1327]

Love seeing the actual results. Great video.

[@LicensePlate]

You are an AMG mad scientist, I love your ideas and thorough effort. Great video

[@ChrisHale0629]

Love these videos. Thanks for going into so much detail.

[@Danialdaneshmand]

Loved this video. especially when you go through details and the basics. Keep going!

[@tyrellboggs2863]

One small problem. The area around the perimeter of the piston is called the quench area and should not have been touched. By removing aluminum from this area can actually increase detonation. You would have been better off taking more out of the center than ever removing anything from the quench zone. If you were to deck your block to gain this quench back it would diminish the amount you removed from the center. Just a bad idea to reduce your compression height by removing aluminum from the quench area. You did not reduce your compression as much as you increased the likelihood of generating detonation. Its the quench ring that extinguishes the flame front and reduces your threshold of detonation. This ring works with as little as 4 mm of radial length but fails entirely when your compression clearance goes beyond .040 inch. You need to have no less than .040 inch quench clearance. I have not done the calculation yet but your .75 mm seems real close to the .040. How far down the cylinder are your pistons at TDC? How thick is your head gasket? In my opinion you are taking some unnecessary risks. Only a person who does not understand quench would play with this quench area. It should be considered sacred especially when you want to run boost. I have been successful burning regular 87 octane fuel in an 11.5:1 engine with correct quench clearances. With out the quench set properly I would have to drop my compression to 9.5:1 to get the same results but with far less power.

[@WookieMonster01]

Awesome videos! Keep them coming. Can't wait for the full step by step rebuild.

[@iDeondrae]

I wish I had a friend like you I’d tune up my RS7 😁you know your stuff sir

[@AbbStar1989]

Wow. I'm liking this series.

[@SupraSmart68]

Tip; always use WD40 or similar when milling aluminium/aluminum to prevent chip welding or gumming up the cutter. Also, remove any sharp corners or edges within the combustion chamber to prevent detonation and stress risers so use a ball end mill to recess or remove material to leave a softer, radiused border, preferably hand blended smooth so there are no abrupt transitions or steps which heat up rapidly and cause knock. Imagine grinding a cutting toolbit for a lathe or a wood chisel and bluing the steel at the corner, drawing the temper. The heat builds up around the edges as it has nowhere to go.

[@smotpoker15]

I'm fairly confident with this gentlemans knowledge and process , doubt he needs first day pointers.

[@anythingbenz4005]

now thats some involved weight reductions hahah

[@marcpollard8792]

thankyou so much.. best vids and commentary ever!

[@azargelin]

Great vid things are coming along but i think u should try to find a shop to coat the pistons

[@samsonn25]

Weekend warrior garage beast!

[@maxfoerster891]

one question: have you thought about litering the pistons? just take a peace of plexyglass withe a whole in it and slowly add colored water drip by drip into ist to see if the macheneing in the middle is equal.. an another one would be to smoothen out the transition between the machened surface in the middle and the unmachened surface around it since sharp edges do lead to earlier detonation...

[@xfmotorsports]

Yes, I did try measuring the compression with a piece of glass. Its hard to get accurate results that way because these are very small changes in volume. And yeh sharp edges are definitely bad. I did sand down the rough edges the machining left but I'll try to do that a bit more before the final install.

[@mrle0719]

you say you don't want to run E85, but have you thought about a flexfuel sensor so that you can have any fuel you want and more ethanol only means more power? (or doesn't it work like that maybe?)

[@psk1w1]

I would expect the outer rim of the piston to be a squish band. It needs to maintain a piston to crown clearance of 0.75 - 1mm, otherwise it becomes ineffective. Losing it will make combustion much slower and less efficient. Better to remove metal elsewhere.

[@builtbyfood]

I have the exhaust stud and copper nut art numbers if you need them still.

[@caba3760]

Thanks for the video!! What place would you recommend for buying gaskets, valves and nuts online??

[@bozejurenic1582]

Great video,I have sl 500 92 year.326hp what should be done on the engine to raise the power to 380 hp

[@jacustomtuning8008]

Amazing stuff keep up bro

[@ezacher4634]

You will pick up a couple psi with same setup when you open up the exhaust.

[@victornenov5146]

Love your videos keep on 👌👏👏👏👏

[@drunichols7705]

What are your thoughts on the effects of decreasing the perimeter crown height (unless you are also running a thinner head gasket) considering the reduction in quench effectiveness? It seems likely that you would have had a better knock threshold if you had left the crown height alone, and reduced your piston cc's by only machining the reverse dome.

[@xfmotorsports]

It's not that critical in these 3 or 4 valve engines. They have a very small quench area. Most versions of the m113 just had a circular crown with no quench area

[@drunichols7705]

@@xfmotorsports I just watched your head Porting & Polishing video. Those quench pads are small! Makes sense, thanks.

[@Dagowly83]

Why did you sacrifice squish when you could have taken it out of the centre more?

[@ProllyHigh666]

These videos are fuckin Krazy I'm watching this shit high with ah clk500 in mi ebay cart ready to fuck up mi rent Money supercharging it🤣🤣🤣

[@ODMIJ084]

Can you talk about the blue car you mentioned briefly at the beginning of the video? What’s the backstory? What kind of work did you do to it? What happened to it? Would love to see a video on an engine failure

[@xfmotorsports]

It had a minor headgasket leak. I gave it to a mechanic for the repair and he charged for a full head gasket replacement and head resurface, but actually just mixed those leak stop things in the coolant and kept driving the car with a blown gasket. Later we reported it to the dealership. After that he did end up fixing the car as well as all the additional damage he did, so I didn't bother mentioning it.

[@eswatwu9122]

So this engine cannot carry over 14.7psi boost? Which grade of fuel do you use? What if I would like to boost until 14.7psi and go for 9.5 or 10 compression, any comments ?

[@axellludvic3490]

By milling down the piston, does the compression ratio decrease? C.R = T.V/C.V where TV is the total displacement volume= swept volume + clearance volume (CV)

[@xfmotorsports]

Yeh, it increases the combustion chamber volume at tdc. Displacement remains the same.

[@khaldrogo9451]

looking good!

[@tomb375]

DUDE!! Awesome Job! Where are you located?

[@nicd5439]

How did you calculate material removal for desired compression ratio?

[@Mccyh]

Hello, Wonder do you have 8 extra Piston and rods for sell? im planning on S32 AMG upgrade to S37 using S350 Cylinder block which requires E55 Pistons set..

[@anashapaq9779]

Niceee job man i like it

[@Antimatter.]

You and Tasos should open a shop together that would be awesome! Was wondering if the M157 engine has forged pistons/ internals ?

[@xfmotorsports]

Lol I wouldn't mind if we were in the same country. I believe they do as far as I have heard but Tasos would be the right person to ask. I've never worked on one of those

[@CLVannoy]

Aren’t the piston coated from factory?!?

[@classicrestouk]

So what's the new compression ratio?

[@adonisduma7047]

So are you going to remain on the e class chassis? I think the only downsides would be the weight distribution(53/47) and the overall weight.

[@xfmotorsports]

I really want to move the turbos to the front and get rid of the supercharger. Its going to be impossible to do on the E55 because of the small engine bay, so I'm trying to figure something. Weight and high CG is a massive draw back too in that chassis

[@Spangarangg]

There's good research that shows that the piston rings spin while the engine is running so clocking the rings is not important.

[@Mortalomena]

They might not spin if all the gaps are on the same point, escaping gasses can keep them in line.

[@Spangarangg]

If that were true, and the rings spin (they 100% do), they would eventually line up by chance and be stuck that way which doesn't happen.

[@xfmotorsports]

That's a long debatable topic. Most engine builders I've talked to say its worth clocking anyways. I know the rings do spin eventually but other people building racing engines that do engine rebuilds more regularly also say they find them at the same place every time. I dont know which one is true but I would say its worth clocking anyways for at least the initial gain in compression it leads to

[@Spangarangg]

SK8215 The study that I am referring to measured the rate of rotation (which depends on all sorts of variables). It doesn’t hurt to clock them though.

[@HomelabExtreme]

I can say for a fact that they do rotate, and quite a lot, i have worked on a lot of smaller engines primarily diesels in the 200-400 cm3 range, those engines are fast to take apart after a test run and check for things like this, and i find that in just 5 minutes, they easily rotate a centimeter, so this shouldn't be a reason to spread the gaps evenly. however if you are going to do a compression test after assembling the engine, it is a good thing to space the ring gaps, so you can rule out the piston ring gaps from being the cause of varying compression from cylinder to cylinder.

[@jareknowak8712]

You should polish the top surface of the piston!

[@HaloHamstur]

Jarek Nowak, needs a nice coating

[@johncrowley5612]

Possibly a bad move removing material from the squish area of the piston-if the squish clearance is too great you will lose the squish effect that concentrates the mixture in the centre of the combustion chamber. That leads to "end gasses" being trapped thus promoting the detonation which you are trying to avoid.

[@xfmotorsports]

I talked about it in the video. Its a very small effect because those heads don't have a big enough quench area anyways. The N/A models of this engine don't even come with pistons with that area at all. Even with heads designed for quench they only provide 4 or 5 extra hp so its a very small effect. Probably worth having the lower compression than keeping the quench in this application

[@johncrowley5612]

SK8215 Thanks- when I get a moment I ll finish watching the video.

[@alexanderfoti]

Great video! Are you running stock ecu?

[@WookieMonster01]

A H watch his other vids

[@xfmotorsports]

Was running stock with AEM FIC. Might go stand alone on the fuel because the stock ecu does give trouble sometimes

[@shahabuddin099]

Have you checked out vrpspeed yet?

[@shahabuddin099]

Yes. Make another video about it.

[@Rafymon98]

Just out of curiosity, if you are planing to raise your boost, meaning more horse power as an objective, why are you not using carillo I beam rods.

[@xfmotorsports]

Depends on your power goals really. I've been told the stock rods can hold up to 20psi. I know beyond that other things will become an issue anyways so I'm planning to stay around there. If it was an engine intended for drag racing maybe I would have made the extra effort, but this is going to be good enough for time attack anyways. Temperatures get really hard to manage for higher boost levels on a time attack setup

[@EuroE55]

Out of curiosity, why didn't you use a thicker head-gasket rather than milling the pistons?

[@xfmotorsports]

There's not too many aftermarket options and also because of the additional risk of the gasket failing. If it was something tried and tested on these cars then I would have possibly gone for it

[@777MAV]

Also while you probably might be fine with mild gasket thickness increase, on V-shaped engines increasing gasket thickness spaces heads not only further from the block but also further apart from each other and in some cases it can introduce problems when you will be putting intake manifold back on. so you might need thicker gaskets there as well...

[@jth1987leb]

I want to know what happened

[@theone3473]

Would it not have been better to machine the whole top of the piston. then you could have left the crown thicker?

[@xfmotorsports]

I could have machined more if I had a CNC, but would have been hard to machine more by hand and still keep it precise

[@0-60STYLE]

Dude wtf was in your oil????

[@Henr1k]

Are you not able to buy custom pistons from CP fex ?

[@marcin1069]

make a separate videa about this guy pls and another car

[@xfmotorsports]

Lol, lets see what he does with the car this time. If he screws up again I definitely wouldn't mind posting

[@joyroc885]

So if you buy a used E55 tear the engine a part and change all the oring or you will be doing a rebuild like this. LOL

[@aaronroberts3848]

Learn how to use a milling machine ! My god haven't u ever heard of an edge finder ? How about a fly cutter ?

[@tischlerbmw21]

Check out a guy named Tasos Moschatos on KZbin he rebuilds all AMG’s. He might be able to tell you where to get some aftermarket rods

[@LukeSportsman]

Pankl and Carrillo both show part numbers

[@tischlerbmw21]

The bearings are so overpriced, what a rip off! I spent $300 for main bearings and I have an account with mercedes.

[@Webrexxx]

Accually, running it on E85 would mean you could get more power on way leaner mixture. Also, E85 produce way more power on same boost, so you could go with lower boost. = less fuel. Also when you lower compression you decrese efficency, by a segnificant amound. So you should really have gone with E85, and left the pistons alone. It would probobly have been a very small difference in milage with E85. if any. Also the risk of detonation is completly elimminated. Not running E85 on a track, when you can, is just foolish.

[@alexstromberg7696]

You do know that you need to pump more fuel to make the same power on e85?

[@Webrexxx]

Yes, isen't that obvious? Thats why I commented. SK8215 probobly knows, just like you, that Etanol has lower energy content than gasoline. About 40% less when its in E85 form. But, that number is not true in real life when you consider what I just commented. Lower compresssion thats atleast 15%, leaner mixture 10%, power gain = less boost = atleast 10%. So now you are down to a 5% difference. And if you go the other route, with higher compression, thats 5-10% more. Now the milage on full power will be less than on gasoline. The only downside is wear on the fuelsystem and you need to change oil more often. But fuel usage on track, with high power output in high boosted application, E85 can be on par with gasoline. Trust me, I tune cars for a living and have raced cars on E85 for 10 years.

[@alexstromberg7696]

@@Webrexxx my dad also works at microsoft

[@Webrexxx]

To bad you're not as smart as him then.