Choosing a used engine

[UsAndThem]

Hi,

I am looking into doing a 3.5L swap and have located an engine candidate from (what I have been told) is wrecked 1986 735i. I haven’t gone to see it yet but am planning to sometime in the next week or so. Can anyone lend some expertise on things in particular to look for and check which would raise major red flags in regards to the engine condition? When I am there, at a minimum, I plan to pull the valve cover look at the cam lobes and check the color as well as signs of head gasket failure. The seller has provided these images as an initial look. My Bavaria is currently carb’d and I plan to keep it that way for the time being. Any advice is greatly appreciated.

Brian

btw, thanks to those who provided suggestions after listening to the video I posted regarding the squealing noise. It turned out to be the alternator bearings.

 

[x_atlas0]

Is there a reason why you want the M30B34 instead of the M30B35? If you are going to do all the work, may as well get the best engine for the job, right?

 

[61porsche]

Used engine inspection

From the Firstfives FAQs:

"Pull the sparkplugs.
Are they all the same in appearance. Do the ceramic tips have a tan color.

Pull the cam cover.
What is the general color and texture. Golden glow. Even coating. No deposits.
(Slimy, gunky, dark brown, dark black are signs of poor oil maintenance)

Feel the cam lobes.
With your trusty fingernail, scratch across the high part of a lobe, especially number one cylinder. You should not feel any ridges. If you do the cam is shot.

Look in the intakes.
They should be spanky clean and free from oil. The aluminum should gleam.

Look at the exhausts Should be an even dull flat black. No white powder look. No oil. All even.

Look in the water ports They should be grunge free. Light white deposits indicate regularly changed antifreeze. There should be no traces of oil.

Check head gasket.
There should be no oil oozing from it. Look over starter area.

Check oil pan.
Leakage should be minimal. Check residue at drain plug.

Overall appearance.
The engine should be relatively clean and free from tons of grunge. If not keep looking. BMW’s are being wrecked every day."


Opinion- One reason for using the B34 or at least the head are the shape of the intake ports for the carbs/ manifold. The B35 head is different with larger ports, has a larger combustion chamber which lowers compression, but has larger valves for better flow.

Conversion- you're still going to have to change from motronic back to distributer- conversion nut, old cam cover.

Based on the pictures:

1. Missing injectors- check the plugs.
2. Water outlet missing; use your old one.

Good luck...