Wtb m20 b27 euro spec pistons

[Ceeker]

Looking for 10.2 : 1 or 9.7 : 1 compression pistons.
i have a super eta which id like to put these into.

pm is best thx

warning: those with nefarious intentions who message with remote emails will be ignored.

[ForcedFirebird]

The seta didn't use the flat pistons like the eta did. The '88 seta was unique in that it used the same piston dome shape and 885 head as the b25 did. If you put flat pistons (even the higher Euro spec 11:1), your compression will be much, much lower with the 885 head.

I have access to a few sets of leaded fuel (9.4:1 early Gulf spec) pistons that we have been using for strokers. When using them with the eta rods/crank and shaving 2mm off the block, they make a 10.5:1 2.7 that utilizes the proper 885 dome.

[Ceeker]

Hey thanks for your reply. Ive read that if u use the seta crank 130mm rods and b25 pistons they will protude 2.5-3.0mm from the block. This would require shaving the piston? I have two complete motors. What compression would i get if using that set up?
looking at most practical and cost saving configuration.

[AWDBOB]

If you’re using an 885 head into a SETA bottom end, you already have the right pistons (but lower comp than ideal if running n/a)

If you don’t have a SETA already, you can use the 2.7L crank and rods with late model “I” pistons and shave 2mm off the deck of the block and get a 9.4:1 2.7l meant for an 885 head

[ForcedFirebird]

^^^you can't shave the block with seta pistons, they are already ~.050" from the head at TDC (you need at least .040" for rod stretch).

If you use 130mm rods and 81mm crank with "i" pistons, the compression height will be 2mm below the deck -

+6mm difference in stroke (3mm up, 3mm down), then using 5mm shorter rods leaves -2mm compression height, so shave the block 2mm. We run this combo in our race cars and they make 180whp/180wtq. The new engines will be using the early Euro (Gulf/leaded spec) 9.4:1 pistons, 84mm m52 crank, 130mm rods, -.5mm block to get ~10.4:1 2.8l. I was able to source a few sets slugs from Europe. My contact still has a few sets, but this last shipment has been tied up in customs for over a month due to covid19. If you want a set, and you don't mind waiting, they have more in both .5mm over and stock 84mm. $550 shipped in conn US.

[LateFan]

FF - your shop's links aren't showing in your sig anymore. Are you allowed to post your contacts here for us?

[Ceeker]

^^^you can't shave the block with seta pistons, they are already ~.050" from the head at TDC (you need at least .040" for rod stretch).

If you use 130mm rods and 81mm crank with "i" pistons, the compression height will be 2mm below the deck -

+6mm difference in stroke (3mm up, 3mm down), then using 5mm shorter rods leaves -2mm compression height, so shave the block 2mm. We run this combo in our race cars and they make 180whp/180wtq. The new engines will be using the early Euro (Gulf/leaded spec) 9.4:1 pistons, 84mm m52 crank, 130mm rods, -.5mm block to get ~10.4:1 2.8l. I was able to source a few sets slugs from Europe. My contact still has a few sets, but this last shipment has been tied up in customs for over a month due to covid19. If you want a set, and you don't mind waiting, they have more in both .5mm over and stock 84mm. $550 shipped in conn US.

Ok so ..i do have the seta bottom end..since i cant shave the block to increase my comp. Can i deck the head without risking any interference?
i will be using a 272 cam chipped 173 dme.
and all 325i related components. What would my comp come too?

for the latter set up aside from using the m52 84mm crank but using my 81mm 130mm rods
using the golf lead fuel none dome pistons. Decking the block 2mm will provide 10.5 compression? Using a 272 cam or something higher like 284
180 whp??

[ForcedFirebird]

FF - your shop's links aren't showing in your sig anymore. Are you allowed to post your contacts here for us?

You have to manually turn signatures "on" with the new site.

Anyone is free to email me: John@m20guru.com or call the office 954.786.3100 (you'll get VM most of the time, though). Also have been better about keeping PM box cleared out lol.

[ForcedFirebird]

If you do the 2.7 crank/rods and 2.5 pistons, shave the block 2mm, the compression naturally goes up to ~9.4:1 from the stock 8.8:1 just from the stroke (180whp engine).

So, if you start with the early Euro pistons (9.4:1 on a stock crank), it would bring you to 10:1.

Unsure what this would net in WHP, haven't dyno'd one yet.

[LateFan]

You have to manually turn signatures "on" with the new site.

Fixed it. Thanks.

[Ceeker]

If you do the 2.7 crank/rods and 2.5 pistons, shave the block 2mm, the compression naturally goes up to ~9.4:1 from the stock 8.8:1 just from the stroke (180whp engine).

ok..thanks for clarification..

lets say im not changjng the seta bottom end

can i shave the head if using all the stock seta bottom end to increase compression?
and ur saying using stock components stock cam will yield me 180 whp thats like 200+ to the crank?
this must be inclusive of a chip and headers?

i am going to be using a 272/272 cam with matching turner chip 17.5 injectors and shniedmann headers. And anything else 325i b25
Related thrown at it.

[ForcedFirebird]

Stock seta is only 8.5:1, even lower than b25. If you shave the head to the max limit (if you go too much, the pistons hit the head), you MIGHT see 8.7:1.

I have a lot of info in this thread: https://www.r3vlimited.com/board/for...hread?t=421924

[Ceeker]

Wow..a debt of gratitude for all that info..took a while..impressive on many counts.

those 9.4 : 1 gulf piston stock bore or over sized?

So.assume: (hate using that word)

if i used ALL stock 325i b25 components - no mods -no throttle boring or extrude honing of intake
your golf pistons and 81mm crank 130mm rods
(Seta bottom end)

i should easily get 180whp

will i need a 272 cam with the 10.4 :1 comp pistons
To achieve the whp?

[ForcedFirebird]

+.5mm and on-sized. Yes, at 10.4:1, should do better then the 9.4:1's did. ;)

[Ceeker]

• Hey So I finally got around to my build..I found some 9.4:! M20 84.5mm pistons and had the block decked 70 thou. Using a 81mm seta crank and rods.
  
  I have about a 1-2mm piston to block deck overlap... The valve reliefs are bigger on these pistons over factory..
  
  Question: will I have interference between valve and piston with a stock head gasket?
  
  Should I get a adjustable cam gear?
  
  thanks for your time.