inline boaring mains caps

[pad4]

thinking of getting a set of new caps for my s block from swiftys

then where can i get the block in line bored (somwhere within driving dist of mcr woul be good), doesnt matter if not though

Pad

[Rusty old S]

MMM, boar ring .its a ring in a male pigs nose, me tinks dis cite nids speel cheek. seriously , i have done my research on line boring and found many that can take 5 thou off caps and line hone ,some can fit new caps and bore, few can machine correctly the rebates for thrust washers on centre cap, and the quotes i had where expensive, my fix, fit centre strap , and keep under 8000 ,problem then cant keep gearbox under it ,dam chinese gears ! R.O.S

[Spider]

Can't help out with where to get it done, sorry on that, but having done a similar precision machining operation, I'd actually make my own cap (not saying there's anything wrong with anyone's off the shelf caps, just they are already drilled and so don't suit the way I'd go about making it) I'd measure the existing cap (a mill with a DRO is a good way to get the required accuracy), then start off with 2 blocks of get a similar sized piece of steel of the right grade. Get them longer than what's needed and bolt them together at the ends. Drill a pilot hole through the 2 blocks, right in the centre on the parting line. Then mount them in a 4 jaw chuck in a lather, bore them to the right diameter, separate them, mount one cap in the mill, clocking off the tunnel just made as the reference, then drill for the dowls and bolts. You may want to consider boring them slightly in to one side more than the other, so the is 'too much' tunnel in one side. Then when spit and measured, that 'taller' cap can be machined (ground even) back to the spot on depth.

When measuring the original cap, torque it down on the block first, check the tunnel is in fact still round, then take it off again. The other - maybe not obvious - important measurement is the depth of the tunnel in the existing cap, from the parting face to the tunnel, they are rarely centred, close but not right on.

Doing it this way will avoid the need to have the bottom face of the block decked and the subsequent raising of the crank in the block.

Take lots of time at each operation and you'll get it right.

[1071bob]

Try Rob Walker engineering,

http://www.robwalkerengineering.com/lin ... aming.html

Based in Oxfordshire and a real nice 'old school' bloke.
Could also try SMMC
viewtopic.php?f=9&t=31
But I think they don't do them 'in house' and the job is sent out, 251 eng can confirm this.

[mini13]

I got mine done by Rob Walker,

[251 ENG]

Line boring / honing is one of the few machining operations we do not do " in house " at SMMC .

In the past we have used several other companies for this and to be fair I have never been 100% happy with any of them .

There are a lot of people say they do it but just take it somewhere else and put there bit on top .

The size required is 2.1460" / 2.1465" , if it is done correctly you should be able to spin crank with two fingers .

Also bear in mind than any metal removed from the block moves the crank away from the gearbox and nearer the cam .

Last block we had done cost well over £500 including swiftune FJ caps .

[Vegard]

I got a picture of inline boaring at Brands Hatch as a matter of fact.

[251 ENG]

[JC T ONE]

Nice one Vegard

[KJW]

That was funny

[guru_1071]

{david anttnborough voice}


......the male.......approaches the female.....slowley and carefully.....as.....not.....to....disturb her, he....waits, then..........POUNCE.....hes on her!


haha

[sandman]