Line Boring Head

[TriniGT]

Is there any local shops that do line boring of engine heads? Reason being I have a project that I am working on the side and the head that I acquired did not come with cam caps nor cams. I sourced a used set of caps and cams from Japan and have them in my possession. Things is cam caps are specific to heads so I need to have the caps and head matched by line boring them so that there are no clearance issues with the cams. Anyone can point me or am I wishing on a star? Failing that I will have to mount the caps and cams and check clearances issues and check with my FSM for clearances to see if I am lucky. I have done quite a bit on the head already so don't want to get a next head now, so far spent about $3000 in headwork and that does not even include parts or porting. Still have to get the guides replaced and reemed and then reinstall everything and wrap it up for a later date.

[DIESELTRINI]

Does that engine use replaceable cam bearings? If it's a late model japanese engine, probably not, as their journals are machined for the cam to run directly on them. In that case, you are right in that the bearing caps are not interchangeable.
I don't think you can do much here. I wouldn't try it with the other caps you got, I think it will seize up very quickly.

[TriniGT]

Yes they do not come with cam bearings but it is a common practice to line bore the caps and cam seats when different caps are used. I need to know who locally does this. When can we get half decent shops that can do a good job down here. Is there even a flow bench locally for porting of heads or is it all guess work, grind something and look at it and say yeah that looking like it will flow good. Most shops don't even gap pistons rings when new forged ones are bought, they just install them and say hey it was made for this application. Bearing clearances, what's that, just buy a set of ACL bearings and yuh good. This place is so backward when it comes to building a reliable engine, when you go for a simple engine rebore for bigger pistons and you enquire about torque plates the machinist is like torque who. It just sickens me that things that are common practice abroad are not even considered locally, things like crank snouts for RB engines, torque plates fro boring, oil restrictors, baffle kits, ring gapping, bearing clearances, proper clearance measuring tools, torque wrenches even, torqueing sequences for specific engines, high-end flow benches for thos high HP or high response people that are willing to spend the extra dosh, proper alignment shops. Can someone bring RIPS or Mazworx to Trinidad please for firetruck sakes. Sorry for the rant just feddup up local dodgy shops claiming to know what they are doing.

[DIESELTRINI]

Yeah that is scary... especially when you spending so much on parts. I guess that is why everybody just swaps complete engines or heads.

[Sanctifier]

What about MIC?

[TriniGT]

They have stopped doing private jobs but I am going to have a look around.

[Sanctifier]

Post when you find a shop please.

[Conrad]

I'm sure if you paid one of those established machine shops like Ziigs in Aranjuez they'll at least be able to do the boring. The cost however....

[TeamH2O]

give me a call if u want me find out from MIC, i know someone working there and does do them ting for me.

[TriniGT]

Yeah I know some guys at mic but tryignt o explain it to them is the problem. The head already has made many a trip to MIC already but if I can get someone that knows exactly what I am talking about that would be ideal. This is cam cap boring we are talking about eh not cylinder boring.

[TriniGT]

I will mock up the head with cam caps alone and once again I need to get an inner micrometer to measure the ID of the cam caps and also measure the OD of the cam shaft itself and work out my tolerances to see how off it is then form there I can see if I can use them or if I need the machine work, I am wishing but let's see.

[cacasplat3]

go to one of the industrial firms with a good machine shop like gulf engineering or IAL, talk to some ppl and see what can be done....dont limit yourself to shops that usually "specialize" in automotive work......u'll be surprised at the kind of machines some of those firms have or the knowledge of some of the persons working there.........not everyone is a quack......i just wish it had less quacks

[zaxxon1]

A couple of years ago, a friend came from Canada and set up a precision machine shop in the Gulf City area. He had all the equipment and knowledge for this kind of work, unfortunately, he said he was not getting the work to maintain the shop so he sold out and returned to Canada. Maybe the people he sold out too can help, only thing, I never went to see his shop but I think it was in that complex next to sting in gulf or the one down by the traffic lights.

I know long ago the motorcity guys used to line bore their 'mini' blocks for circuit racing, (dont know by who), Zigs used to do lots of cams and head work. I think the problem would be the cost to set up the jig to do a job like that and the time involved. They may not think it is worth the effort. I will ask around and let you know if I hear anything positive too. Its nice to hear someone actually doing this sort of build here. Hope you succeed.

[DIESELTRINI]

Agreed. The setup for that job would take alot of time and probably cost quite a bit.
Here is my question... If you line-bore the cam bearing surfaces, won't the dimensions be oversized for the camshaft journals? The cam just rides on the alloy head machined surface right?

Or does the new cam have oversized jounals?

[Monk BANzai]

if A1's link does not go through I know a director at MIC who i channel my technical work through (they did the work for the Medussa Head for the Vr4...)

[Sanctifier]

... If you line-bore the cam bearing surfaces, won't the dimensions be oversized for the camshaft journals?...

AFAIK, the mating surfaces on each journal have to be milled/ground perfectly horizontally first.

That reduces internal journal diameter... then mount... mark (i.d.)... torque... and line bore to spec.

My $0.02¢

[Monk BANzai]

... If you line-bore the cam bearing surfaces, won't the dimensions be oversized for the camshaft journals?...

AFAIK, the two bosses on each journal have to be milled/ground perfectly horizontally first.

That reduces internal journal diameter... then mount... mark (i.d.)... torque... and line bore to spec.

My $0.02¢

yeah but what would you be using as a "guide"? this sounds like a catch-22 situation to me....

We've had to hand make some bits for out SR project ....and it took Karl having to GO to the shop with skematics to show them exactly what needs to be done after they say 'nah it cant be done".....you need a technical person who will not take NO for an answer..

ofocurse it helps to back it up with moderate sized pockets.....if i told yall the prep work costs on the SR 16 head alone....ha lord.

Good luck tho Jason....if it works out share with us for future reference..

[Sanctifier]

Not sure... a trained machinest should be able to explain, I suppose.
The same proceedure is used when line-boring main bearing crankshaft journals in cylinder blocks...

Link--> ~ From The Archives ~ A Guide To Engine Blueprinting.

[Maserati]

good link there Sancti

[turbohead]

baldwin does good work also.

[Sanctifier]

...yeah but what would you be using as a "guide"?...

BANzai here's the grinder & fixture used to ensure correct registration of the camshaft journal caps.
Article also shows what happens when machinist screws up... and how to correct it.

Link--> Align Honing Principles.

BTW TriniGT... pm dry BEFORE going to Baldwin for cylinder head work.

[Monk BANzai]

Great read. I always thought that Honing was like honing a head using Extrude Honing where its done from one side...but in this article, they're talking about doing it from both sides.

But with doing it from one side, the prinicple of getting the same diameters comes into play....similar to why i did the Medussa Head to allow for equal distribution of the Nitrous to each cylinder.

Defn a good way for measuring the journal caps.

[TriniGT]

Thanks for all the help and input guys will be searching soon. Will let you know what surfaces. Also, Sanctifier, I spoke to Dry a while back on that sore topic.

[Sanctifier]

^ ^ ^ BTW check D. Rampersad in Chaguanas.

[TriniGT]

Will do, have some other things in the works so this is really a backburner project as the enigne is functioning fine right now. This can happen later in the year, the RB26 build is in full swing now as the sump is done and I am starting measuring clearances now for the build.

[TriniGT]

I may have found a local shop that can do it. Will keep all posted, changing valve guides and having them reemed and head pressure tested and polished. After which I will be reshimming and I should be good to go.

[B20VTEK]

updates?

[TriniGT]

Salt, head home here winking at meh .

[rado]

... Is there even a flow bench locally for porting of heads or is it all guess work, grind something and look at it and say yeah that looking like it will flow good. ....

A small step forward!

At least there is an alternative to guess work with respect to head porting.

Richard.

[TriniGT]

Are you saying you all have a flow bench? Also looking for someone that can replace valve guides in an aluminum head and reem them to suit, please don't tell me Baldwins because they afraid to do it, the supposedly biggest machine shop in Trinidad.