Engine bearings for AC Aceca

[MaseratiTMC]

I'm looking into an AC Aceca that needs an engine rebuild.  Are there companies that supply bearings, connecting rods, etc?   I presume any oversized pistons would have to be made, is there someone in the UK that has already done that?

I'm guessing I will have to bore this out at least +20.



Best Regards, Philip

[AEX146]

Philip,
If you are still looking at the Aceca and would like to discuss the engine rebuild: I'd be happy to share my experience albeit from 5 years ago.
Regards,
Ben Morgan

[Big col]

Yes, Philip, there are a couple of suppliers advertised in the owners magazine,
ACtion.
Due to the cylinders being removable wet liners it is not usual to rebore them but replace them and use the original pistons with new rings.
It may be worth using the new style gaskets designed and developed by Rod Briggs.

[Aussie16/70]

Hi Ben Morgan and all I've just started my rebuilding process and down here in Oz there aren't too many prewar AC's left, for support.  I'd really appreciate any help, tips and traps that you discovered during your build.  I'd be very keen to hear about cylinder liner gasket compression measurements, as well as cam shaft lift shape etc. not sure if my cam shaft is worn or the undercut it is part of the profile.
My block is pretty solid apart from one head stud that has a 7" hole down the middle (from the bottom)  I'll extract that, worst case put in a 7/16BSF stepped to 3/8" stud, unless anyone has advice otherwise.

[AEX146]

Philip,
I should start by saying I'm not an engineer. I'm happy to share my experience of a few years ago having my AC engine rebuilt which led me to be current on where to source parts etc.

As regards your specific questions: 1. Head gasket seal. You can find a lot of discussion on this subject on earlier Forum threads. The liners seal at the bottom on paper gaskets and engine builders often use more than one gasket to ensure a good seal. The liners protrude above the top of the block. AC advised a protrusion of 6-8thou but some engine builders increase this to 10thou or more if using the traditional copper type of head gasket used.

[AEX146]

Continued

AC recommended torquing the head bolts to 40lbs ft.

2. Head bolts. Some engine builders advocate drilling through the head stud webs and using a longer stud with a nut at the end rather than relying on the thread. This allows additional head torque.
3. I don't have anything on the cam measurements.

I hope this is helpful. Regards, Ben

[Aussie16/70]

Thanks Ben, do you know if Rod Briggs stock has been taken by anyone yet?  I've tried contacting Richard Woolmer, but his email keeps bouncing. Tony. PS I'm only new at this engine, but I thought the copper figure 8 gaskets go at the bottom of the cylinder liners and the head gasket at the top. I'll check out the other forum info

[AEX146]

The biggest issue for an AC engine is ensuring a good head seal between the aluminium block and cast iron head. Original copper head gaskets crush down considerably hence the debate about the height the liners should protrude above the line of the block.

I have one of Robin Woolmer's gaskets which uses more modern materials which are less crushable so we stuck to AC's 6 thou specification.

As far as I know the liners seal at the bottom with paper gaskets. For the reason above you don't want to allow the liners to sink.

I don't know what, if anything, has happened to Rod Briggs business and stock since his death. As far as I know Robin Woolmer's e mail is Robin.woolmer@zen.co.uk. Let me know if you don't get a reply and I'll call him.

Regards,
Ben

[Aussie16/70]

I am rebuilding my engine now and making new main bearing caps that will suit Mini Shell bearings.
If anyone wants me to make them a set, please let me know.
CNC machined 6061 Aluminium

[Aussie16/70]

I am also about to remake Conrods if anyone wants a set let me know and I can do a group discount.

has anybody used modern pistons, (like a Honda CB900F),  I know they use Kawasaki pistons in Bristols as they are cheaper, strong and have good sealing.