E30 Touring 3.0L M20 Stoker Build

[ForcedFirebird]

The single tang bearings have a 360° oil groove.

I am not sold on the modification, many high HP OEM designs have smooth shells. Having been a beach bum skin boarder for quite some time (many years ago, tho), I feel even the 180° grooves are unnecessary.

[ForcedFirebird]

To add, I have never had any clearance issues with b28 cranks in m20 blocks - even the one I built without turning the crank weights (I modified the piston skirts), the customer car has been daily driving it for over 2yr now (plus the 3yr it was a track car was before cutting the cage out and installing an interior). It's the 217whp/202wtq b28 we did in 2014 and 16 with stock .5mm over slugs, 130mm rods, .5mm off the deck, IE 272 cam, RHD ITB.

[digger]

There is a thread on speed talk about grooves 180, 360 etc. same with the thrust. 360 groove are old school thinking was the outcome. 360 are Rarely if ever needed infact the opinions were they are actually worse (and not from the obvious negatives to the mains which on an online 6 are not an issue)

I thought KS twin tang were 360 but glyco were 180 could be mistaken

[ForcedFirebird]

I love speedtalk! Been a member for many many years, probably longer than here. Curtis, AFR, Vizzard, CamKing, Knight etc are extremely knowledgeable, and so willing to share with competent inquisitive minds. Many if those guys compete in the EMC.

TractorSport waalso an excellent wealth of information, but probably haven't been there in about a decade - the site changed hands and names and is now flowbench.com or something (out of town to attend first born's collegiate graduation, going on memory)
. TS.com /FLB.com was the first group that designed pass around plates so many of us could calibrate out flow benches so numbers are more universal. That's the guys that caused me to learn boundary later, Coanda effect, the importance of shirt side radii and valve angles/back cuts. Mostly just PM on those sites, rarely post.

I use KS bearing often, unless a customer requests OEM shells (stupid expensive and buying one shell per box...), I can say early shells are 360° groove, late is single 180. Assembled enough m20's to know that much. Also in a pinch, you can miss and match the shells for desired results if you have multiple partial sets. ;) All the 24v engines have 180 and work just fine, all the GM and other US domestic stuff we do are all smooth.

However, I do prefer a 360° thrust. Thrust clearance and contact is ignored by many, but even when replacing the bearings in my Ford Excursion V10 haul vehicle ("gasser" we call them in the States, you might call the "petrolers" rofl) I went ahead and purchased a second set of shells just to make it 360° and it's approaching 300,000mi of severe duty. Seemed silly to have the caps and block recessed for a 360, but install a 180 in something that can haul 8-9 tons, and weighs 3.503 tons empty (yes I weighed it, 7,007lb no driver, 1/2 tank if fuel). Thrust bearings don't really rob any power and have the same "skim board" effect referenced earlier. Also fun note, my truck prefers 0-20w oil, 30w or more and I get piston slap at light throttle no load, specially on lower octane (87 vs 91). Heavy loads and high TQ low RPM engines need the thrust as the cranks tend to walk back, adversely cams tend to move forward.

[digger]

the nominal dimensions should be

206.2+84/2-22.5 = 225.7
206.2-84/2-22.5 = 141.7

but the delta is the important part

does it have a machine step for the tooth wheel on number 6 counterweight?

i measured 225.5 and 141.6 with a vernier depth gauge on a b25 block (no HG) obd2 b28 crank which aligns pretty well with the theory

[E30-TourZing]

i measured 225.5 and 141.6 with a vernier depth gauge on a b25 block (no HG) obd2 b28 crank which aligns pretty well with the theory

Sorry for my late response guys. I have been pretty busy with the M6, Christmas and skiing. This evening I had to move my block off the stand to make room for a subaru motor I am rebuilding this weekend, and I was inspired to spend some time measuring the block. I need to get a vernier depth gauge, or atleast borrow one to get 100% accurate measurements on the crank throw, but I feel my measurement is pretty much on-point.

My two block measurements are (from the top of the main bearing cap - Top of block) 172.14mm

Bottom of block - top of block) 263mm

Can anyone tell me their block height for reference. Beyond the crank throw, I am worried my block may be decked to far... I will have to measure everything up, but I hoping this will be the first step.

My block is from a 86' 325E

Thank you!

[digger]

im not sure what you mean for that first measurement

but top of block ( HG gasket face) to bottom (sump gasket face ) is 266.1 to 266.2mm

the main cap part line is 60.0 mm from the sump skirt so add the 206.2mm deck height and that gives 266.2 above.

Measure the deck height (from main cap part line to top) this is the key. Yours looks like it will come out at 203.x in Which case it looks like someone skimmed 3mm off yours