E30 Stroker 2.7L CA Smog Questions

[mkcman17]

What cam are you using?

Regrind ~274. have been running this setup since 2012

[Rockonp04]

I built my 2.7i (88 bottom in 89 body) with a regrind cam, 17# injectors, and a knock off chip and my car has passed bi-annual smog the last three times on its own in socal

What cam are you using?

[mkcman17]

I built my 2.7i (88 bottom in 89 body) with a regrind cam, 17# injectors, and a knock off chip and my car has passed bi-annual smog the last three times on its own in socal

[Rockonp04]

I have had a discussion with Bimmerheads about passing smog with certain pistons and cams. They have a set of pistons with a compression ratio of 9:1 with the 274 cam which they claim will pass smog. I think this will be my current path. No idea what piston shape they have.

[medgingt]

I'd highly recommend going with a piston that uses the OE dome as others have suggested. If you don't want to go with the 2.9, Top End have JEs that fit the bill as Digger pointed out. Especially since you are worried about Smog...the correct combustion chamber will be your friend.

[Rockonp04]

An update on the build. I purchased some 17lb green top injectors from Injector Planet. https://www.injectorplanet.com/produ...mw-13641730060. These, for now, work with my current stock setup and I think will be adequate with the 2.8 stroker.

I am still going to do the forged pistons from Ireland Engineering but had some questions about cams. I really want to pass smog no problem and don't want to have to register my car in Arizona. I've head videos of the 272 cam and it seems lopey and heard about the overlap issues. I am leaning toward a stock cam at the moment just to avoid the hassle. I am not looking for crazy horsepower just something better than stock.

What is everyone's thoughts with a stroker, with a stock cam, 17lbs injectors, and an upgraded chip?

[Rockonp04]

An update on the build. I purchased some 17lb green top injectors from Injector Planet. https://www.injectorplanet.com/produ...mw-13641730060. These, for now, work with my current stock setup and I think will be adequate with the 2.8 stroker.

I am still going to do the forged pistons from Ireland Engineering but had some questions about cams. I really want to pass smog no problem and don't want to have to register my car in Arizona. I've head videos of the 272 cam and it seems lopey and heard about the overlap issues. I am leaning toward a stock cam at the moment just to avoid the hassle. I am not looking for crazy horsepower just something better than stock.

What is everyone's thoughts with a stroker, with a stock cam, 17lbs injectors, and an upgraded chip?

[ForcedFirebird]

Yeah, budget-wise the Mhale are more expensive, but usually cost vs quality is often reflected in price.

[Rockonp04]

You do realize Jeff carries a very specific piston for you expectations, that a "local" member "skifree" did all the research on, and got Mhale to produce a correct piston for you intended use.

Ultimately, it is YOUR engine, this is just a stupid online forum for a bunch or e30 fanatics to hang out and shoot poo.......BUTTTT!!!


Not for nothing, the guys who are having good results, "should" be the guys you are listening to. :p

Jeff is who I have been talking to and he has the exact piston which will work for this stroker kit. I could go with the Ireland Engineering 2.9 Mahle piston kit but I am not pushing my luck for smog and blowing my budget. The custom forged piston Jeff supplies will work perfectly for my application. That's what I am going to do and I am sticking to it.

This is the piston set I am going to use.

https://www.iemotorsport.com/product/custom-forged-pistons-m20/

[ForcedFirebird]

You do realize Jeff carries a very specific piston for you expectations, that a "local" member "skifree" did all the research on, and got Mhale to produce a correct piston for you intended use.

Ultimately, it is YOUR engine, this is just a stupid online forum for a bunch or e30 fanatics to hang out and shoot poo.......BUTTTT!!!


Not for nothing, the guys who are having good results, "should" be the guys you are listening to. :p

[Rockonp04]

After a long think, I decided just to go with the custom forged pistons from Ireland Engineering. Also, when calculating the budget for a 2.9L engine build it was significantly more than the 2.7L build. I respect your opinion on the Mahle pistons but after talking to Jeff I don't see a huge advantage to spending the extra money and also I would like to pass smog in California. Thank you for showing me all the alternatives before jumping into this build. As they say, knowledge is power.

[digger]

I think I understand your point now. You are referencing these pistons.https://www.iemotorsport.com/product...-ie-mahle-m20/

I would be making a 2.9L and not a 2.8 using these pistons. It seems I could use pretty much all of my M20B25 block, rods, and head with this, just only have to buy a M52 crank, right? I think I understand your point about the wear of the piston now.

Any advice on this build? Is it that simple to just throw these pistons and the M52 crank in?

You need the m52 crank and a sleeve / new crank bolt (from24v engine) and thinner washer. Ie probably can sell you or metric mechanic and other vendors

[Rockonp04]

i highly recommend to stick with their Mahle MS ones in that case, the other 2618 alloys wear poorly, rattle when cold etc due to the low silicon content and associated high expansion. They are actually inferior to stock cast pistons in many ways, most forged pistons are. That's why Andrew (formerly IE) worked with Mahle MS to develop them for the street. if you want something for a non street application or very low mileage or very high boost then 2618 will work but don't fall into the trap that almost everyone else does thinking forged pistons are magic and need no engineering.

I think I understand your point now. You are referencing these pistons.https://www.iemotorsport.com/product...-ie-mahle-m20/

I would be making a 2.9L and not a 2.8 using these pistons. It seems I could use pretty much all of my M20B25 block, rods, and head with this, just only have to buy a M52 crank, right? I think I understand your point about the wear of the piston now.

Any advice on this build? Is it that simple to just throw these pistons and the M52 crank in?

[Rockonp04]

i highly recommend to stick with their Mahle MS ones in that case, the other 2618 alloys wear poorly, rattle when cold etc due to the low silicon content and associated high expansion. They are actually inferior to stock cast pistons in many ways, most forged pistons are. That's why Andrew (formerly IE) worked with Mahle MS to develop them for the street. if you want something for a non street application or very low mileage or very high boost then 2618 will work but don't fall into the trap that almost everyone else does thinking forged pistons are magic and need no engineering.

Are you referring to these pistons here? https://www.iemotorsport.com/product...0b25-8-8-1-cr/

If that's the case then I have to find another way to complete my stroker. From what I understand, these are the stock pistons so I would have to find another way to do the stroker. Also, this is just a street car not a performance car and I won't be hauling ass around the track. If I am missing something, enlighten me. I would like to keep the stroker simple with just changing the crank and the piston if possible.

[digger]

I am going to stick with the IE pistons. Best fit for my build. I am interested in the model number for the Bosche Mustang 19 lb V8 injectors. I also found someone selling Bosche Gen 3 19lbs injectors off of BMW v8s. I've also heard the mustang injectors do not have notches for installing clips on. I also heard about the M50 injectors. Would these pop in with the clip as well?

i highly recommend to stick with their Mahle MS ones in that case, the other 2618 alloys wear poorly, rattle when cold etc due to the low silicon content and associated high expansion. They are actually inferior to stock cast pistons in many ways, most forged pistons are. That's why Andrew (formerly IE) worked with Mahle MS to develop them for the street. if you want something for a non street application or very low mileage or very high boost then 2618 will work but don't fall into the trap that almost everyone else does thinking forged pistons are magic and need no engineering.