Porting & polishing heads?

[caduceus]

Has anyone done this to their Rover V8? Are there any gains to be seen? Or are the heads pretty good as standard?
I only ask as I have the engine out at the moment and in the process of cleaning it up prior to painting. I noticed some casting detritus inside a few of the intake runners, also the exhaust runners.
I understand you should not polish the intakes, nor remove any significant material in the inlets as this unbalances the volumes. Seeing as that's not what I'm looking to do anyway, it's not an issue. Just looking to smooth the lumps out of the rough castings and make it flow a bit better. May polish the exhaust ports.

Any tips, info or advice on this is appreciated.

Cad

[caduceus]

Thanks for the replies so far chaps.
Here are a few pics taken this morning:






The last picture of the cam shows some discolouration on some of the cam lobes. Is this normal heat discolouration, or signs of excessive wear?

I haven't had a look at the inlet manifold in terms of how well the ports alignyet, as it's buried in the shed somewhere. But will dig it out today.

[caduceus]

One other thing - when I do remove the heads, is there anything majorly difficult about removing the double valve springs? I have only ever removed valves & springs from an old XR2 head many years ago, and still have the valve spring compressing tool. Is removal any different for double springs?

Cheers

[caduceus]

davep said:

The cam lobe wear line pattern is not uniform, this is due to lifter alignment/rotation, and is quite normal. If a cam is suspect what you're looking for is worn or rounded cam lobe points.

Not really suspecting cam wear. Only a visible marker after seeing this. But it's making 263bhp and 299lbft, so not too shabby already.
If the porting releases a few more torques and ponies, and/or better throttle response, I'll be happy.

[caduceus]

Bobby Shaftoe said:

Cad, they look stock heads, but post a pic of the valve seat/throat area when you get the valves removed as this is the first area for improvement

Didn't get round to removing the valves tonight, but did get the heads off. To find this:





The water in the last one may be from where it was sitting in the back garden for a couple of months, in all weathers. Albeit covered in a tarp.

I assume the crusty black deposits are way too excessive? Running too rich? Or something more?

[caduceus]

Boosted LS1 said:

The water is probably from the head because you didn't drain the block. Don't panic he he. Yes, rich and oily. How are the inlet valve stems and the valve seals looking?

Not got them out yet. Will be on that job tomorrow. Along with painting wishbones and uprights... :|

[caduceus]

So the valves are out. One exhaust valve had to be tapped out quite firmly with a hammer It wasn't the valve at fault, as the same happened with a different one. Fook knows what's caused that...








On the whole, they all look very grubby. A lap in job is necessary at least. Not too sure how to proceed at this point, apart from cleaning up and lapping valves, porting any rough casting in the head. The fact that single valve had to be hammered out is a little worrying. Also the amount of carbon and crud in the combustion chamber looks excessive.
I assume it's prudent to renew the valve stem seals and the little round springs that fit over them?

Will have another read through Bobby's posts as I seem to remember him mentioning upgrading something.

Any other advice appreciated.

[caduceus]

Sardonicus said:

It may have previously shed a rocker pad in the past this mushrooms the top of the valve stem I would never have forced the valve through the guide because if my previous is correct then chances are you have just damaged or scored a serviceable valve guide (do check)

I understand your concern and duly noted. But that same valve does go through a different exhaust valve. For some reason the dodgey valve guide seems too small or warped

[caduceus]

Sardonicus said:

hat too Caduceus may be worth getting those tight guides reamed then

I've already had a look into buying a new valves/springs/followers/stem seals kit from RPi. The chap I spoke to was happy to spend over half an hour on the phone talking about issues and things to check.

The followers appear to have the 'halo' signs on the face, showing early signs of wear. But from what I can see of the cam, the lobes still look pretty egg shaped to me. I'm sure there is a more technical term than 'egg shaped' but you catch my drift. Although I'm happy to be corrected on the integrity of a 42k mile cam being due a change. Just saying what I see...
The valves themselves aren't looking too clever. I left them soaking in 'Gunk' and a few in carb & intake cleaner overnight and it doesn't appear to have broken down any of the s**t stuck to them. The exhaust valves are particularly pitted.

RPi also do an upgraded ignition and ecu chip kit to correct the over fuelling. Mine IS over fueling quite badly, as shown from the pics of crust in the chamber/valves and pistonheads.

So, I'm slowly gathering info to help me make an informed decision as to where I should spend my hard earned wedge.

[caduceus]

Sardonicus said:

hos going to tell him? .... chip for over-fueling cure (news to me) and the little ignition upgrade box? Upgrade.. yeh right should of spoke to Realsteel concerning valves and guides

Eh

Why so serious? I'm only repeating what a guy said who has been tuning RV8's for decades. If I've missed something by all means enlighten me. It's not something to get upset about.
I will also check the Realsteel website, so thank you for the tip.

[caduceus]

The negative feedback re RPi is a little worrying. What a bloody minefield! Are we saying that the valves/springs/lifters/seals,etc they supply aren't much cop either?
I haven't committed to buying anything yet, so need some definitive course to pursue before I part with the folding green.

For now I'm going to get on with sourcing some long shank carbide burr sets (if I can find any that is..) in the UK and carry out the suggested work, albeit tentatively :|
I assume its best to lap the valve seats in using the old valves, assuming I'm getting like for like?

[caduceus]

phazed said:

You should be lapping the valves that you want to use into their matched valve seats.

Lap in with new valves - check :

On the subject of valves (thanks again Bobby for your detailed reply ) I have measure the inlet and exhaust and they are the following size: Inlet- 41.33mm exhaust- 35.43 (yes, they were cleaned in a wire brush mill before hand). These numbers are obviously higher than what you quoted. Does that mean mine are BV heads? I doubt it, but have to ask.

You were right about the inlets being already done with a flap wheel. Can't tell with the ex ports yet as they're carbonned to hell, even after a good scrub with 'Gunk'.

With regard to de shrouding the valves - do you mean de shrouding the combustion chamber around the valves? If so, I don't think I'll be doing that as I don't want to touch the chamber and upset the cc volumes. This is a steep learning curve for me so I apologise for what comes across as ignorance. But you have to start somewhere and I'm eager to learn and expand my knowledge.

I have made one call to Real steel so far, and the chap on the other end coughed heavily throughout the conversation, before the line going dead. So wasn't too impressed with that. But will try again.

[caduceus]

Bobby Shaftoe said:

(someone may have run a flap wheel around the valve throat to remove the small step in the aluminium just past the seat that's often present, but it's hard to tell from the pics)

I've taken a couple of pics of the now cleaned up combustion chamber, and it does indeed look like someone has been here before, porting:





I don't know what 'stage' this resembles, but I'm thinking just the runners need doing. How much will a company charge to do a 3 angle valve job and press in new seats?

I will remove the cam and check for wear, but if I'm going to change the lifters then I'd might as well renew the cam. Whatever one is in there seeing as the valves are not standard....

[caduceus]

I took the camshaft out this morning after finally removing the crankshaft timing gear.
The cam lobes don't look too bad in terms of shape. So I measured them with a digital caliper (at the highest point/measurement. But by no means a scientific exercise). The pic below showing the measurements. They are obviously not uniform as it's a used shaft. But how do these numbers stack up in terms of wear? Anything alarming to the trained eye?

Also some pics of the worn followers. 'B' indicating the least worn, and 'W' the worst.







The numbers from left to right, are taken from the back of the cam to the front/pulley end.

[caduceus]

Sorry yes, I should have added I was going to replace the followers along with the cam. They're fooked. The springs, stem seals and valve guides also being renewed. I didn't see any real wear on the rocker shaft so will just clean the rockers and re-use. Not too sure about the keepers/retainers. Will take a pic and see if someone can tell me if they are the crappy stock rover ones or double valve ones, as mentioned earlier in the thread by someone.

[caduceus]

Bobby Shaftoe said:

If you have stock Rover powdered metal retainers, replace them with a billet steel dual retainer. TVR fitted stock single spring retainers to most dual valve spring heads and it's a massive bodge/cost saving exercise. I've seen both cracked retainers, and broken inner valve springs (as the inner spring sits on a chamfer rather than a proper boss as per a dual spring retainer)

Bobby (or anyone else who can), would you be kind enough to identify these please? Are they the Rover ones or the billet dual retainer?




Many thanks
Cad

[caduceus]

Thanks for the quick reply Bobby.
This is the cam number, but it means nothing to me



The rocker shaft, under two of the rockers:




I'm not too sure what a radius cut on the seats is. But here are a couple of pics. I have been de-cocking the ex ports and have noticed that a flap wheel has been in there to some extent, but to no great degree.




With regard to the followers, yes, you can feel the dip on a few of them, and most show daylight under a straight edge on top. So they are all pretty much scrap.

The seats ars they stand, are not in too great a shape. So looks like I might be getting new ones pressed in. How much am I looking at for that job? This is beginning to snowball