Piston rings and rod bearings sizes, part numbers etc.

[digger]

The reason I say oe bolts is you are supposed get them resized with ARP or if you use a different preload to ensure the rod bore is round after tightening Otherwise they might go out of round. The bolt gets taxed more by rpm ( tension inertia loads) than compressive cylinder pressures

[The Red Baron]

I hear you guys, I will be using OEM bolts for the mains, but I am absolutely going to buy arp for the rod ends, so I will be buying the 53mm arp bolts unless anyone else can chime in that these are not appropriate to use.

[ForcedFirebird]

^^I agree with Digger. OE bolts are pretty stout, run them up to 7500 RPM no problem, and you really should have the big end of the rod resized when changing fasteners.

[digger]

Standard bolts for stock m20 rods are are 53mm according to realoem. I'd probably stick with oe bolts

[The Red Baron]

im stuck on arp rod bolt part number not knowing whether to get:
ARP 201-6301 - for m50\m50tu -or-
ARP 201-6303 - for m52\m52tu\m54

I believe the specs im looking for are M9x53mm correct? because that would then mean I need the 201-6301's, the 6303 are M9x47mm

[The Red Baron]

11 24 1 284 849, Rod Bearing Set
11 21 1 706 849, Main Bearing Set






11 24 1 713 342, Connecting Rod Bolt

awesome, thank you..I did find the main and rod bearing sizes to use. ive ordered the glyco ones, although I appreciate your suggestion forcefirebird. as for the rod bolts, do you happen to know the part number for the ARP ones? being boosted id like that added security. I don't mind paying the extra buck.


I will need the part number for new Main bolts, I forgot to mention. will I need an alignment hone for using OEM main bolts? is that hone for the cylinder? or the threads for the bolts themselves? I was alittle confused on reading that topic earlier.

[ForcedFirebird]

the lower rod bearings are single tang.
the main bearings are double tang.

11 24 1 284 849, Rod Bearing Set
11 21 1 706 849, Main Bearing Set

I need to know which rod bolts to order.. can anyone help me with that? Perhaps a part number?

11 24 1 713 342, Connecting Rod Bolt

[The Red Baron]

I need to know which rod bolts to order.. can anyone help me with that? Perhaps a part number?

[The Red Baron]

^^^those are the wrong rings. Thge seta pistons use the same rings as the other eta motors.

Been using kolbenschmidt bearings in builds for years without issues.

Providing you with a part number for main bearings won't be much help since there were 2 different style bearings and you don't know what you have until you open the block. Some have 2 2mm locating tabs, later blocks have a single 2.9mm tab.

All m20 and m/s5x (except s54 and s50b32 euro) use the same rod bearing shells.

The m20 engine will handle 400whp no problem so long as you use head studs and either an MLS head gasket or o-ring the block.

I have used stock rods and rod bolts to 7500rpm, 200+whp N/A, and 400whp with boost in previous builds, many of them are daily drivers.

the lower rod bearings are single tang.
the main bearings are double tang.

[TobyB]

Whups, you're right, I used the wrong year.

t

[ForcedFirebird]

^^^those are the wrong rings. Thge seta pistons use the same rings as the other eta motors.

Been using kolbenschmidt bearings in builds for years without issues.

Providing you with a part number for main bearings won't be much help since there were 2 different style bearings and you don't know what you have until you open the block. Some have 2 2mm locating tabs, later blocks have a single 2.9mm tab.

All m20 and m/s5x (except s54 and s50b32 euro) use the same rod bearing shells.

The m20 engine will handle 400whp no problem so long as you use head studs and either an MLS head gasket or o-ring the block.

I have used stock rods and rod bolts to 7500rpm, 200+whp N/A, and 400whp with boost in previous builds, many of them are daily drivers.

[TobyB]

https://www.autohausaz.com/catalog/c/bmw/1990/1011700-325i_e30_sedan/20-engine_parts_seals_gaskets/10312-piston_ring_set?s=d&page=1

https://www.autohausaz.com/catalog/c/bmw/1990/1011700-325i_e30_sedan/20-engine_parts_seals_gaskets/10300-connecting_rod_bearing_set?s=d&page=1

for starters.

I would use ARP rod bolts.

Beyond that, everything's pretty understressed,
if you keep it below 6500.
And keep your a/f ratios good.

I don't buy critical car parts from eBang.
And how a rod from Hong Kong gets genuine
ARP bolts in it is a bit of a mental stretch for me.

hth

t

[The Red Baron]

I am currently building my IX motor with a SETA crank, rods and pistons. I've got everything super cleaned and ready for assembly but I need to purchase rings, and bearings first.

1)First question is about rings. I know they're 84MM Bore.. but I want to buy GOETZE rings, and I cant seem to find a part number. Can anyone give me a number, or a place i can buy a set of 6 for a really good price?

2)Second question is about rod and main bearings. I've been reading that glyco bearings are what I should be using. Again I cant seem to find a part number for either ros or main bearings. Anyone able to source these in sets for a good price?

3) I am running boots on this setup, so I was curious about whether or not to upgrade the rods, rod bearings, and rod bolts to ARP. Then I came across these for sale, and read that in Europe, alot of people are using them with good success.

Maxspeeding forged h-beam connecting rods.
https://m.ebay.com/itm/Connecting-Ro...-/222006533776
The reviews are good and the price is surprisingly outstanding and they come with ARP bolts.

I also never heard of these before either but for connecting ros bearings, they seem affordable and are suppose to beat coated and of better material. CATUNED is selling them, so I dont think they can be that bad... anyone have any input on these?
King rod/main bearings

https://catuned.com/king-race-performance-bmw-engine-rod-bearings

Anyway, I need to know where I can also source main studs, and whether i should be just going with OEM BMW main studs, or if I should use ARP. the maximum HP this motor will ever see will be about 400WHP, but probably more like 280 - 340 for majority of its life. I'm running megasquirt with 93oct. And only between 12 - 18psi.

Any input and direction would help me greatly.. I'm hoping to start buying parts within the next day or so and want the best bang for the money. Hoping to find out what's going to be more cost effective.. and if those performance parts are worth it, I will gladly buy them over OEM parts.