Sr20 oil pump cover not flush with deck

Hi guys,

I'm doing an engine refresh to oem specs on a n15 pulsar sr20de.

The oil pump doesn't sit flush on the exhaust side, but fine on the intake side. Machine shop said my deck didn't require resurfacing and is true. The engine was running and had no issues prior to disassembly. I'm guessing it was distorted when I tried to take the cover off? Anyone know what would be an acceptable tolerance? I'm using a Durapro graphite gasket.

I can't see noticeable cracks or anything on the cover. Should I just get that machine too or replace?

Cheers

The cover is made from cast aluminum so I don't think it distorted when taking it off. If all the dowel pins align and it doesn't sit flush when bolted, I would get it machined as well.

Yep, dowels lined up. That's so weird, nfi why it doesn't sit right when the deck wasn't touched.. groan. Back to the machine shop I go i suppose..

I'm guessing the surface tolerance would be that of the deck surface hey?

If it's just that step you're concerned about, it isn't really uncommon. Its not something caused by distortion on removal, but it was made like that.

If the dowels correctly align the seal, etc, with the crank centre line, then you can simply file the step off, taking it back as far as you feel it's needed. Whether I would bother depends on how bad it is, and the vehicles usage.

I mean, there is no compression pressure at this place on the deck, but if the step is too high, it could prevent sealing of the first cylinder as the head would be lifted a bit. Of course, the best scenario would be that the whole engine deck is flush so the head sits well. If you file your front cover a bit lower than the deck, the head gasket would probably seal it as only oil splashing occurs in the area.

Thanks lads, that is what I wanted to hear. I think I know what to do. I will take to it with a sanding block with some fine sand paper and make it flush. The step isn't as bad as first inspected. I think the fear of being my first build has stopped me from thinking straight. Thanks for the sanity check.