Had a chance to drive the car this past weekend before all the little final touches had been completed. Besides, I had to Aircare the car before I can re-insure the vehicle so it’s roadworthy. Aircare is our province’s way of addressing smog emissions. I think it’s more a government cash grab myself but oh well…
Started up the car and it idled smooth. The typical characteristic lumpy idle in our S38’s is not noticeable. Idle was smooth and flat, better than stock. You wouldn’t think there was anything done to this car. Honestly, I was worried that the Schrick 280’s would produce a really rough idle. But this wasn’t the case! Farrell’s engine building experience (he’s built Cosworth engines as well as motorcycle racing engines) and his meticulous attention to detail putting together this engine really paid dividends here. Throw in Dan’s customs tunes and you’ve got something special in this seemingly normal sounding S38.
Brody and I drove around to warm up the engine to get it to its optimal operating temperatures so that it’ll hopefully pass Aircare. It’s been awhile since driving this car and forgot how tight and short the action of the UUC EVO3 shifter/DSSR setup was on my car. I let up the clutch and barely touched the throttle and the car just started to move. Ok, this is different, I remember I had to give it a little bit of throttle to get the typical heavy mass of steel the E34 was. Not this time. Shifted easy into second gear at 3000 rpm and the throttle drop off was not as apparent as before. Shifted to 3 rd gear and took it easy, had to fight back the temptation to bury the throttle, especially when the oil temps were only about 75 degrees. Coolant temps barely went past halfway. Weird, it use to be a little higher, just slightly past middle. Oh yeah, did I mention it was like 31-32 degress C (90 F) in Abbotsford.
Ok, finally got the oil temp up to 95 C. Let see what Mr Knight will do…
Slipped it into first gear and proceeded with a rolling launch…
Mashed the throttle (but not fully pegged to the floor) and let up on the clutch and took it to 6000 in first gear (yes, it’s a little low as I wasn’t as confident to push it too high, sort of like a pro athlete returning from an injury and doesn’t want to push it too hard on the first time back out). Crap, that went too fast, quickly dropped the clutch and pulled back the gear shift into second and quickly eased the clutch back up and mashed the throttle again (still not fully pegged to the floor). Holy Crap, looked at the speedo, WTF, I’m already doing 120 kph. Damn. The engine didn’t want to stop building rpms…had to let up to third gear and finally coasted into fourth gear as we eventually ran out of road. Wow, I almost forgot how nice the S38 felt and sounded, but this time it just felt much stronger. There was definitely more torque than before. Guess almost 0.4 L’s more of displacement really helps?
I had to catch my breath.
Time to take it to Aircare and have the emissions tested. Brody directed me to the closest Aircare station and we hopped out for the tester to take the readings. They put the car on the dyno and inserted the exhaust probe and proceeded to take the readings. No sooner did Brody and I see the tester put it into 2 nd and finally into 3rd gear did the testing end. Man, that was fast! Brody and I took guesses at what to expect when the tester proceeded to print out my results. Will I get the little “booklet” or won’t I (the “booklet” would normally signal I had failed emissions and the information in this book would tell me what I should do next time to pass Aircare)…
The tester tore off the results turned around and passed the printout to me, “Congratulations sir, you passed”….
Woohoo! Boy was I relieved! The emissions numbers were better than before the rebuild (I forgot to mention that we reinstalled the original stock exhaust system back onto the car). So I guess my OEM cats are still in good working order!
We decided to head back and find a place to park and take pictures of the car. On the way to there, I decided to do a run in 2 nd gear to see how it feels maintaining a steady speed starting at 2000 rpm and accelerating from that point forward. I firmly pressed the throttle and the engine started to build revs. As soon as I hit 3400 – 3500 rpms, something happened. It felt like something really opened up and all of a sudden there was just gobs of torque, as the revs climbed it didn’t seem like the torque would left off. This continued right to 6600 rpm’s before I shifted up to 3rd. I don’t recall feeling this in the stock system before! I like it! No, I love it! I have a feeling the resonance flap action in the S38 with the larger displacement is now making it more pronounced than ever before! Maybe someone more technical might be able to explain this. But for now, I’m absolutely lovin it!
Here are a few pictures we snapped before returning back to the shop.
There are a few little things that needs to be worked out with the car but the majority of the engine rebuild work is complete. I’ll follow up with some more detailed updates when I get the car back.
Aside from using Schrick cams, what other upgrades did you do? Did you port or just polish your head ports? The JE pistons were stock compression ratio or increased? Stock rods? Any other head work. How much did you bore out the block?
I am planning on buying a s38b36 or b38 engine and slowly building it over the years until i find a suitable donor. Just wondering what you did to yours.
The bore was enlarged to 94.5mm and we also went with a slighter larger stroke as well, I can't remember the exact stroke but it's definitely over 92mm. Farrell port matched the manifolds but I'm not sure if he went as far as polishing them. We had to shave a bit off the piston as the high duration of the Schricks was too close to the crown. It was something Farrell was not very comfortable with having tolerances so tight, especially trying to maintain streetability of the engine. The JE pistons were suppose to bump the compression a bit but with the slight shaving of the pistons, he brought it back to stock compression ratio. I know we put slightly larger injectors as well but can't remember what we finally decided on. Right now, we're just waiting on a few more maintenance items to fix up the little things.
I'm hoping to get the build list soon from Brody and once we've itemized all the things, will we'll try to post what we had done for this build.
Do you know if he ported or polished the cylinder head at all? Or did he just match the manifolds?
I'll find out this weekend when I pick up the car.
Originally Posted by Lantz
Fantastic results, congratulations!
So you are basically driving a 4.0L S38B36 now?
Also this thread is useless without videos
Yes, just barely 4.0L but close! Don't worry, will be working on some videos. Need to figure out how to mount my Playbook in the car to record in HD...
Originally Posted by mottati
Perhaps i missed it in the thread, but is the builder "our" m5board member Farrell, from the UK, who used to post frequently on the board?
And yes, more pics, i'd like to see the paint work on the plenum!
No, but maybe long lost brothers? Honestly though, they definitely share the same work ethics when it comes to rebuilding these engines. From what I was told, Farrell absolutely loved building this engine. He had nothing but praise with how the BMW engineers designed this engine. I think he built up the engine and tore it apart again several times just to get it the way he was satisfied with it. Definitely a great guy to talk to, especially over a pint to discuss philosophy!
Originally Posted by Luxauto
Beautiful project, I'll have to look you up next time I'm in town!
I really hope those AFRs aren't accurate- at 13.4:1 (MINIMUM?!?) and those power levels you're asking for another melted piston, IMO.
Did you already take it through a proper break in period before dyno, etc? Did you take it past 6500RPM on the dyno?, the power is still climbing on the chart!
Definitely, we can compare cars!
The high AFR was on the original stock engine before we rebuilt it. This is identified as Run #2. Run #1 was the rebuilt engine.
Dan went with a conservative tune after the rebuild so the AFR's are where they should be in run #1.
Everyone has a unique way of breaking in the engine after the rebuild. As long as it's done consistently and works, they will stick with this method. I'm getting the car back so I can put a little break in mileage on the car, especially before our late summer ends. The power does taper off at around 6100 rpm so I won't be going past 6500 rpm that often . Then it's heading back to Miller for some followup work that I'd like to have done.