Line-bore B230 cam bearing surfaces?

[thelocalspoke]

Is this even really possible? It seems to me that if a head gasket surface needs cutting to fix any lack of flatness, the cam bearings will be misaligned as well. But, if you fix that, they will be too large a diameter for your cam.

I have a bare 530 head here that, if you lay a cam in its bearings, will rock a bit at the ends. If you think maybe the cam is not straight (it is), all you gotta do is rotate and keep checking.

I've read a bunch of threads on heads, including the Classics, not gonna list them here. In many cases, "line-boring" is casually referred to as desirable or sometimes necessary, but with no explanation of how to correct the diameters of the resultant holes.

**Yes, I can get--probably have already--a better head. I'm gonna get this one cleaned and checked at machine shop, maybe just to use for porting practice.

BUT, I still wanna know: can line-boring be done here correctly? Welding? Bearing inserts? Inquiring minds...

 

[centason]

Probably John V can answer. I've heard of doing it to the mains with oversized bearings, but I'm not sure if they sell oversized cam bearings. Hiperfauto may know the answer to that.

 

[photoman327]

the cap torque at 15 lbs and the cam run in the soft material with no bearings. the caps are number in the engines i have messed with and it not number them before removing. If you are building a race engine and blue printing by all means go for it. Not every shop can do line boring nor do they have the eq. If mine need line boring, i would find another head. Line boring mean taking it back to the factory spec. by taking material of the caps the boring the the hole back to spec.

 

[blkaplan]

Theres no reason you can't line bore the factory cam caps. Its probably adviseable to get new ones but you could also have existing caps shortened and then re- bore it.

 

[thelocalspoke]

...Line boring mean taking it back to the factory spec. by taking material of the caps the boring the the hole back to spec.

thanks, I had not thought of that. this is the answer I was looking for.

 

[lummert]

They remove material from the mating surface of the caps and head before align boring. This will allow material for the align boring.

 

[John V outside agitator]

No reason except the cost of the job...particular the job done right...Few shops ever buy the hones which are very expensive and its time consuming to fiddle faddle with the things creeping up to the exact journal size..

When a head is warped badly---and cam line banana-ed---first you straighten the head BEFORE surfacing the thing...if its a head you need to keep.

 

[hiperfauto]

Bearing inserts are available. I happened to notice they were listed in the catalog for cam and intermediate shaft bearings. They also sell the tools for machining the head.

 

[burstcurse]

your head is a banana. get one that is flat.

if your head is warped but within spec and has not been decked then the cam bearings will straighten out when you bolt in onto the block. and you will be good.


if your head is warped and then decked to be straight. it is garbage

you can try to line bore the cam bearings... but then the valve cover is going to leak also.

you can have the valve cover side of the head decked but the lifter buckets will be crooked and not perpendicular to the axis of the cam then what do you do about that?

get the lifter bores honed straight and perpendicular to the cam right then where do you get bigger lifters and shims.. plus the valve stems will be crooked to along with the ports, valve seats.


intake leaks and exhaust leaks after how many $$$$ to try to save a garbage head?

 

[The Jolly Roller]

Unfortunately, removing material from cam cover surface will put cam seal(s) out of concentricity with front/rear camshaft journals. Align honing, removes less material than align boring.

 

[culberro]

I'm with John on this one. Get the head straightened in an oven, and then check the cam fit and the deck.

You could bore the cam journals, but that is a serious amount of work with a Volvo head (two seal mounts, 5 cam journals). Unless there's major money spent on it, it's probably better to start with a different head.

 

[Redwood Chair]

your head is a banana. get one that is flat.

if your head is warped but within spec and has not been decked then the cam bearings will straighten out when you bolt in onto the block. and you will be good.


if your head is warped and then decked to be straight. it is garbage

you can try to line bore the cam bearings... but then the valve cover is going to leak also.

you can have the valve cover side of the head decked but the lifter buckets will be crooked and not perpendicular to the axis of the cam then what do you do about that?

get the lifter bores honed straight and perpendicular to the cam right then where do you get bigger lifters and shims.. plus the valve stems will be crooked to along with the ports, valve seats.


intake leaks and exhaust leaks after how many $$$$ to try to save a garbage head?

$8K to save an $80 head?

 

[John V outside agitator]

Unfortunately, removing material from cam cover surface will put cam seal(s) out of concentricity with front/rear camshaft journals. Align honing, removes less material than align boring.

Derp Derp....Uuuuh.

Isn't the amount of material to be removed a function of how banana-ed the head is and how much comes off the flat---and not the cutter/or stone you use?

Front seal register is easy...Done dood that on heads costing 15 times what a 8v Volvo head costs...

Whaddo I know?

 

[centason]

your head is a banana. get one that is flat.

if your head is warped but within spec and has not been decked then the cam bearings will straighten out when you bolt in onto the block. and you will be good.


if your head is warped and then decked to be straight. it is garbage

you can try to line bore the cam bearings... but then the valve cover is going to leak also.

you can have the valve cover side of the head decked but the lifter buckets will be crooked and not perpendicular to the axis of the cam then what do you do about that?

get the lifter bores honed straight and perpendicular to the cam right then where do you get bigger lifters and shims.. plus the valve stems will be crooked to along with the ports, valve seats.


intake leaks and exhaust leaks after how many $$$$ to try to save a garbage head?

 

[The Jolly Roller]

Regardless the condition of the cylinder head ("banana'd" or pretzeled), the valvetrain layout in the 1000160 - 1000531 OHC series (which is a straightforward (if not an enigmatic ) piece of engineering), puts the camshaft load (with exception of cam belt tension on front bearing) against the bearing caps, not the in-head journals, as witnessed when the camshaft rises off the head as bearing caps are sequentially removed per Green 'Bible' proclamation. In an assembled head, no fewer than three valves are open at any time, applying pressure against the camshaft via the followers (buckets), making 'work-bench' measurements of camshaft "rocking" in a disassembled head dubious. However, the Preponderate, those willing to "Gird up their loins", by torquing a disassembled head on to a 'torque plate' (or, a properly prepared block) with obligatory fasteners (stock, ARP) and stand-in head gasket representative (stock composite, MLS, Weetabix Box-Tops?) to that used in the final assembly and installing camshaft, torquing cap nuts to 14-15 lb-ft (18.981-20.337 Newton Metres ), can then check camshaft play with a dial indicator. If binding exists, loosen bearing caps one at a time, if binding remains, re-torque cap nuts, proceed to next cap. Once the retentive culprit(s) is/are disclosed, consultation with your friendly Machine-Shop Dalek ("Exterminate Imperfections!"), will help direct the weary traveler to the path of cam and head Nirvana...Or, the 'cash for metal' Alchemist.

Vi Ses Senare'

P.S. This Is what I know The Jolly Roller