another Alfa Romeo conversion

[delcowizzid]

how many slots you got in that balancer LOL

[Jayme]

id swap the leads over and try it, it can only go 2 ways we fluked the datto dfi's on the first go

[antus]

@delcowizzid: the 4 cyl dfi uses 6+1 notches, so that looks correct

[festy]

I tried swapping the coil leads over, no firing at all that way.
So checked the cam timing at TDC - looks ok except the inlet is half a tooth retarded.

inlet_cam.jpg (61.26 KiB) Viewed 4342 times

But I have a nasty feeling I've got a pair of exhaust cams in the engine - no wonder it won't run, check out the valve overlap!

cams.jpg (69.7 KiB) Viewed 4342 times

[VL400]

That aint going to be helping things On a side note, thats some serious valve angle. A bit like the old Toyota 18RG design.

[festy]

80 degree angle apparently, the engine remained essentially the same from the 50s to the 90s. It was pretty advanced in it's day.
Here's what the front cam lobe positions *should* be:

lobe_diagram.jpg (13.98 KiB) Viewed 4331 times

As soon as i took he cam cover off this morning I knew something wasn't right, but as the cam markings lined up I wasn't so sure - it didn't occur to me that I might have put the wrong cam in until I was thinking about it later

[delcowizzid]

just turn the exhaust cam 180 degrees a lot of the twin cam exhaust cams have a more aggressive lobe profile and people use 2 exhausts or mix and match to get there desired cam profile

[festy]

The factory inlet and exhaust cams are both identical so I just turned it round. I'd forgotten that they had timing marks on both sides - it's been years since I've played with these engines.
Timing light confirmed it's firing on TDC, I'll shift the crank sensor to give it about 7 deg advance and see how that goes.

[festy]

Somehow, installing the inlet cam upside down didn't bend any valves
I added about 7 degrees of advance by modifying the crank sensor bracket, opened the plug gaps right up, and changed the ref angle in the cal to 70, and kicked it over.















And it started.


Still so much to do, but gotta say i'm pretty happy.

[VL400]

Good stuff hopefully no more manifold busting backfires