Turbo M20 2.8L Stroker w/ 135mm rods

[ForcedFirebird]

No, just trying to deliver the obvious commonsense to the regular user.
You might have built a lot of engines but it doesn't mean that you built them right, no? It is a great mistake to deck the block and I am sure a lot of people will regret your advice at a later stage when they decide to go after a bigger displacement after finding that there are better options than 2.8L.
With regard to Digger, are you his assistant/secretary? I don't mind talking to the "staff" if the "boss" is alright with it.

Dude, if my engines are winning races, WTF more proof do you need? You think the work load would be what it is here if they didn't last? Proof is in the pudding, I have thousands of dyno graphs to proof my ideas, whereas you just have keyboard diarrhea.

Digger and I have been conversing about these engines for a decade, it's only natural for two people who approach things scientifically to come to the similar conclusions.

Exactly have many m20's have you built? I'm sure I could look at shop records and site a number.

BTW Just went and measured the "0" punched in the block. Difficult to measure so I pressed a piece of tin solder in it and came up with just over ~.010 (2.5mm). So, an extra shave is not going to be the death of the OP's block - specially if he was to take the max .010 and take the rest off the head. I rather leave the heads as full height as possible, though, since shaving it removes the quench band.

Man this is getting way over my head, but I'm glad that you guys have responded so I can learn a little bit.

I took my block to the machine shop today. He is going to acid bath it and mic it this week. Once he measures the bore I will order the proper sized pistons, hopefully I can stick with the standard 84mm bore, as I'd really like to have a square engine.

According to you guys there is so much more that goes into this however, and quench/swirl and Deck height in relation to the pistons are something I am not too familiar with.

What do I need to do as far as quench/swirl? Just tell my piston manufacturer I am using an 885 head and they will handle it? Do they need to know my deck height or something?

Also, I think I'd like to go with 9:1 compression, being that I will be full time E85 and can take advantage of the higher compression without worrying about too much detonation. Do you guys see any downsides to this? Or suggest a better ratio?

If I haven't mentioned it before, I will be attempting to make 500-600whp on this engine, and It will be used in a car that will see a few drift events a year.

Thanks again guys!

A basic stock b25 rebuild with factory matching forged pistons, Bimmerheads dual pattern regrind, and a p6267 just pulled 518whp/550tq at 19psi locally, so don't sweat obtaining those numbers with your stroker.

As far as quench, with a boosted engine, it is more important than N/A as it reduces hot spots and potential detonation. To get a good quench, square and deck the block, bore it, replace the intermediate shaft bearings (be cautions and make sure your machinist understands the procedure). Then you will fit your pistons/crank/rods. Finally you will want to use a sacrificial head gasket (only thing VR gasket is good for lol) and torque it down with used bolts, but before mounting it, place a pieces of solder on the angle part of the piston. Some people like to use clay, but I find the solder is easier to measure (not a bad idea to also do the piston to valve clearance at this time). If the solder is more than .037" by a good margin, shave the head to match.

For pistons, just use the factory style with the raised wrist pin to compensate for the longer rods, and factory dome, you won't need anything special. Many piston MFGR's already have the files to avoid a custom piston fee.

Did you have a MFGR in mind already?

EDIT: Missed the part about compression. Go with as much as your tuner feels comfortable with, but I haven't had an issue going as high as 10:1. Local here has an e39 m5 with stock compression (never opened, 11:1), and is making 780whp @1bar with only meth for charge cooling (no FMIC).

[MrBurgundy]

Right. But you should have addressed this to the EngineBuildingBird, not to me. I am on your side on this issue.

This apostate dude has always been a D bag. IDK why you keep combating the most knowledgeable people on this forum... Seriously, you're so fucking annoying dude.

[apostate]

Just a note.

An American "engine builder" tried to educate me.
Pathetic.

"Dude", what I have built you cannot even imagine.

Good night. I will bother no one no more.

[MrBurgundy]

Just a note.

An American "engine builder" tried to educate me.
Pathetic.

"Dude", what I have built you cannot even imagine.

Good night. I will bother no one no more.

You've said that before, yet here we are. You buzz around people like an annoying mosquito.

[ForcedFirebird]

This apostate dude has always been a D bag. IDK why you keep combating the most knowledgeable people on this forum... Seriously, you're so fucking annoying dude.

You've said that before, yet here we are. You buzz around people like an annoying mosquito.

Glad I'm not the only one.

Just a note.

An American "engine builder" tried to educate me.
Pathetic.

"Dude", what I have built you cannot even imagine.

Good night. I will bother no one no more.

Good. Maybe you will come back with some real info, rather than just arguing with everyone. And please by all means, entertain my curiosity of these imaginable things.

BTW you are also in America, we live in the USA.

[apostate]

Have a good time.
I will get out of the way, so you can discuss all this nonsense you discuss anyways in this thread.

By the way:
Real info is on the 402 meter strip.

[digger]

Right. But you should have addressed this to the EngineBuildingBird, not to me. I am on your side on this issue.

I'm not on anyone's side other than the engine, keep the engine happy I say. There is more than one way to skin a cat.

If I was doing the budget 2.8l I would deck the block as it's the best way with parts at hand , if I wanted to build a 3.1l I'd get a different block as option 1 mainly to build it in parallel and keep car on the road, option 2 would be a thicker gasket. Others may choose other options it's their perogative

[ForcedFirebird]

Have a good time.
I will get out of the way, so you can discuss all this nonsense you discuss anyways in this thread.

By the way:
Real info is on the 402 meter strip.

...and? I was building muscle cars before I got an e30, hence the ForcedFirebird (aka turbo Firebird). You think I have no 1/4mi experience? lol.

It's just more fun to have three of four "402's" in every lap for hours on end, rather than 2-3 runs all night.

[MrBurgundy]

Have a good time.
I will get out of the way, so you can discuss all this nonsense you discuss anyways in this thread.

By the way:
Real info is on the 402 meter strip.

lol

digger and forcedfirebird talking about built m20s is nonsense?

GTFO brah

[SLEEPYDUB]

A basic stock b25 rebuild with factory matching forged pistons, Bimmerheads dual pattern regrind, and a p6267 just pulled 518whp/550tq at 19psi locally, so don't sweat obtaining those numbers with your stroker.

As far as quench, with a boosted engine, it is more important than N/A as it reduces hot spots and potential detonation. To get a good quench, square and deck the block, bore it, replace the intermediate shaft bearings (be cautions and make sure your machinist understands the procedure). Then you will fit your pistons/crank/rods. Finally you will want to use a sacrificial head gasket (only thing VR gasket is good for lol) and torque it down with used bolts, but before mounting it, place a pieces of solder on the angle part of the piston. Some people like to use clay, but I find the solder is easier to measure (not a bad idea to also do the piston to valve clearance at this time). If the solder is more than .037" by a good margin, shave the head to match.

For pistons, just use the factory style with the raised wrist pin to compensate for the longer rods, and factory dome, you won't need anything special. Many piston MFGR's already have the files to avoid a custom piston fee.

Did you have a MFGR in mind already?

EDIT: Missed the part about compression. Go with as much as your tuner feels comfortable with, but I haven't had an issue going as high as 10:1. Local here has an e39 m5 with stock compression (never opened, 11:1), and is making 780whp @1bar with only meth for charge cooling (no FMIC).

Wow that is impressive for an otherwise stock B25. I was running 25psi on my B25 and my B27 on a 6266 and E85 using the Bimmerheards 280/274 dual pattern, Id like to assume I made close to that same power. My engine held the power fine, but it let go while riding the limiter, so I'm assuming that is the reason for the damage...I hope...

As for quench, my machinist shouldn't have a problem with squaring, decking, and boring the block.

As for the intermediate shaft bearings, these are the ones that the oil pump shaft sets into, and where the snout of the crank and the rear of the crank set into? Is this the part you said to make sure the machinist understands the procedure?

So when I fit the rotating assembly, I need to go ahead and buy a VR gasket just to use for this procedure, set the cam and bottom end to TDC, torque the head down with the solder, and that pinch in the solder will give me my measurement. I think we can handle that part.

Piston wise, I've had good luck with JE and was going to see what they have to offer. I am also open to suggestions on MFGR and CR.

Thanks again

[apostate]

lol

digger and forcedfirebird talking about built m20s is nonsense?

GTFO brah

Absolute nonsense.
Believe.
Goodbye.

[ForcedFirebird]

It has upgraded rods as well. Sadly, though, he thought my engines were too expensive, so he purchased a rotating assy elsewhere and it's already pressurizing the crank case after a month of daily driving. I have a feeling the builder set the ring gap too tight since his previous engine (also from same builder) chipped the ring lands. We put a 3.15 from a z3 in it so top of 3rd is 120mph, and boy does it get there quickly. Forgot to mention it does have a t4 back housing and ball bearing journals.

Yes, the intermediate shaft bearings are what the oil pump shaft rides on in the block. They don't press in like standard cam bearings in a pushrod, they need to be pressed in square, then burnished to size as not all pump shafts have equal diameters, and the beatings themselves collapse during installation. Don't forget the needle bearings in the distributor dummy and block.

Use the solder method, yes, simple. Don't even need to be at TDC when you place the head. If you rotate the crank 20° clockwise, all the pistons will be below the deck. As mormal, put the head on the mark, mount it, then you can back the crank to TDC and it will mash your solder. I personally prefer to put the belt on and check them all as I have found many heads that were not heat-straightened before they were shaved and the chambers will vary on the quench band. These ~30yr old heads have gone through a lot lol.

[apostate]

"Use the solder method, yes, simple. Don't even need to be at TDC when you place the head. "

And scrap everything.

[ForcedFirebird]

"Use the solder method, yes, simple. Don't even need to be at TDC when you place the head. "

And scrap everything.

Yes, prostate, that is correct except for the scrap part. I don't know about you, but every in-line engine I worked on the last 22 years, you set number one to TDC, then rotate the crank an extra 20° and all of your Pistons will be far below the deck. The only way the valves would touch them would be if you took the retainer off and drop them through the guide.

[SLEEPYDUB]

It has upgraded rods as well. Sadly, though, he thought my engines were too expensive, so he purchased a rotating assy elsewhere and it's already pressurizing the crank case after a month of daily driving. I have a feeling the builder set the ring gap too tight since his previous engine (also from same builder) chipped the ring lands. We put a 3.15 from a z3 in it so top of 3rd is 120mph, and boy does it get there quickly. Forgot to mention it does have a t4 back housing and ball bearing journals.

Yes, the intermediate shaft bearings are what the oil pump shaft rides on in the block. They don't press in like standard cam bearings in a pushrod, they need to be pressed in square, then burnished to size as not all pump shafts have equal diameters, and the beatings themselves collapse during installation. Don't forget the needle bearings in the distributor dummy and block.

Use the solder method, yes, simple. Don't even need to be at TDC when you place the head. If you rotate the crank 20° clockwise, all the pistons will be below the deck. As mormal, put the head on the mark, mount it, then you can back the crank to TDC and it will mash your solder. I personally prefer to put the belt on and check them all as I have found many heads that were not heat-straightened before they were shaved and the chambers will vary on the quench band. These ~30yr old heads have gone through a lot lol.

Well that sucks about the rings, do you have a specific gap that should be used for this application? Do you have any links on how to proper install the intermediate shaft bearings?