Hi all,
I have a 1982 e21 315. I've just fully rebuild the engine. The cylinders were overbored from the stock 84mm to 87mm. The stroke was increased from 71mm to 84mm (s14 crank). It's also got the S14 144mm connecting rods. Both the head and block have been decked 4 thousands of an inch. It has custom forged pistons from IE for 10.5:1 compression ratio. It's got 2 dcoe 40 carbs running an IE intake manifold, Schrick 292 cam, TEP headers Ansa sport exhaust. When it was new it made 74 bhp and top speed was 154 kph, 96 mph. Before the rebuild with just the cam intake carbs and exhaust the power went up to ~ 112 bhp and top speed was 183 kph. Now though it makes no power, can barely get to 110 kph. I've played around with the cam timing and ignition timing to no avail. I'm currently stumped as to why it makes so little power. If anyone has any ideas it'd be welcome.
Rebuild engine
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- Newbee
- Posts: 1
- Joined: Mon Feb 13, 2023 11:39 am
- My E21(s): 79 US 320i manual
- BertjeConti
- E21 Mad
- Posts: 3007
- Joined: Mon Nov 04, 2013 9:49 pm
- My E21(s): E12 520-6
- Location: nederland , Weert
Re: Rebuild engine
I'd suggest to do a compression test at first and go from there
Megasquirted '77 E12 520-6
Aspen Silver '96 E39 523i
Re: Rebuild engine
Yep, compression. Then valve clearance, then cam-timing, then ignition. Not playing around, but adjust it to the base setting.
When that all is ok, check for leaks, lost sparks etc. After that, go to base settings of the carbs and check the CO.
When that all is ok, check for leaks, lost sparks etc. After that, go to base settings of the carbs and check the CO.