Head Gasket blunder..?

seanmx5 · Postby **seanmx5** » Mon Oct 10, 2016 10:01 pm

Hey so I've made some more progress on the engine rebuild. Had the bp4w head reconditioned and bottom end pulled apart checked and bolted back up. Everything looks in check!
VRS kit installed.
So..... I went to install the intake manifold gasket and realised it was the wrong one! The one received sat too low. So I had my suspicionson that I was sold the wrong kit. A search on VRS kit part number and it came up as the part for a Mazda Mx5 89-98 model.
My Big Big problem is that I have already fitted the new head gasket torqued the head back on with timing belts etc.... Have I installed a gasket totally incompatible with my NB8A...?
Basically I've installed a 89-98 Head gasket to my 98 NB8A bpw4 head.
Is this disastrous or can I run with it.
Would a coolant reroute help with anything?
Thank you in advanced.

hks_kansei · Postby **hks_kansei** » Mon Oct 10, 2016 10:09 pm

As far as I know the head gasket is the same for the 1.8 until about 2000/01 when it went to the nb8b which had diff cooling galleries (double check though, I lmay be remembering by models/years wrong)

Not sure why the listing says 1989 start.... That was the b6, which has diff bore spacing so would have been obviously wrong (if it even lined up at all)

As far as he intake manifold gasket, the nb8a had the intake ports in a higher position than the na8 did.
So yeah, with a new intake mani gasket it should all work.

seanmx5 · Postby **seanmx5** » Mon Oct 10, 2016 10:38 pm

Hey Kansei

That's exactly what I was hoping to here! Thank God!
Yes it all lined up perfectly as I recall. Just some holes were blocked as the old one did.
Only pics I had are the old one and the new one still in the pack.
Ayway.. if all is good I'm confident and ready to transplant this fresh motor back in...
Thanks mate. Happy

seanmx5 · Postby **seanmx5** » Mon Oct 10, 2016 11:00 pm

Here they are

3gress · Postby **3gress** » Tue Oct 11, 2016 1:24 pm

I believe the head gasket design for all model 1.8 bp engines changed after 2001 to block a coolant gallery and even out the heating across all cylinders. Im pretty sure your old and new head gaskets would be the same. Coolant reroute is a good idea though :DIY:

rascal · Postby **rascal** » Tue Oct 11, 2016 2:52 pm

I've had the same issue with a few VRS sets for my NB8A. A few of the vendors just list the same part number for NA8 and NB8A probably because the rest of the gaskets are the same. (just not the intake manifold one) I always check for hi port IM gasket now.

low port gasket for NA8 on hi port NB8A head.

Coolant reroute is a good idea and can be done quite cost effectively if you are even mildly handy on the tools.
I did my complete coolant reroute for less than $50 and I'm hardly a qualified mechanic.
.

seanmx5 · Postby **seanmx5** » Tue Oct 11, 2016 3:35 pm

Thanks for putting me at ease guys.
Yes. I have already purchased the intake manifold gasket replacement.
The re route adapter should be on route to delivery from mx5 plus at.
Did you utilise a specific hose /part number for the hose from back of head to radiator? Or should I go a hard alloy pipe in between as seen on some YouTube vdos?
Thanks