Porting & polishing heads?
Discussion
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 should of spoke to Realsteel concerning valves and guides 
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.
This ^^^^. The stock engine does not over fuel unless something is wrong, its not inherent. RPIs chips are the Mark Adams Tornados that are best guess at best, and Ive yet to see any real proven gains apart from your wallet being £400 lighter. As for the ignition unit- I went to the effort of bench testing one along side the Lucas Amp- and guess what the available HT voltage was LOWER- this is not what the sales blurb says- thats utter fiction. The amp has a longer spark duration time, so the available dwell is shorter, so the HT drops as the RPM increases, so in no way is it better than the stock amp. You need to talk to the genuine experts who wont sell you a pile of expensive hardware you dont need.
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?
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?
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.
Interesting comments about port shapes .. the inlets on my 5 litre race engine (JE heads) have the central ridge taken out completely and they're the biggest RV8 ports I think I've ever seen .. makes good top end but not sparkling low/mid power but might be the cam ..
These are the heads I've just done for myself, std valve sizes. A bit of an excercise on a pair of spare heads I've had kicking around for about 8 years just to see what happens really.
These are the heads I've just done for myself, std valve sizes. A bit of an excercise on a pair of spare heads I've had kicking around for about 8 years just to see what happens really.
caduceus said:
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.
Next will be the leads ,new dizzy and a little box which does nothing .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.
http://www.ebay.co.uk/itm/Rover-V8-Optimax-EFi-Ign...
Edited by SILICONEKID345HP on Thursday 4th February 11:59
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....
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.
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.
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.
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
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
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
Bobby Shaftoe said:
The stock rover valves have a huge 45' face, and the actual seat cut is usually near the inner edge of the valve, so not even making best use of the valves in a well undervalved engine. Good gains to be made in moving the seat out towards the outside edge of the valve, backcutting the inlet valve around 30/35 degrees and putting a bottoming cut on the seat.
Is their any advantage moving the seats out on big 500 valves also what's the standard angle of 500 valve seats?Thanks, Steve
stevesprint said:
Bobby Shaftoe said:
The stock rover valves have a huge 45' face, and the actual seat cut is usually near the inner edge of the valve, so not even making best use of the valves in a well undervalved engine. Good gains to be made in moving the seat out towards the outside edge of the valve, backcutting the inlet valve around 30/35 degrees and putting a bottoming cut on the seat.
Is their any advantage moving the seats out on big 500 valves also what's the standard angle of 500 valve seats?Thanks, Steve
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