Just a few of my projects/products...needle bearing with ball bearing thrust turbo upgrade...roller rockers...timming chain cover...pushrods with sleeves..
not all complete yet but getting there..
Just a few of my projects/products...needle bearing with ball bearing thrust turbo upgrade...roller rockers...timming chain cover...pushrods with sleeves..
not all complete yet but getting there..
top stuff matey. Pretty sure most would love some of your gear.
Sid having just fitted my cam cover over a vernier it was the middle bolt that was catching bud that cover will have to have a more central raised face to it bud to fit nicely.. I simply tested mine to fit.. But I can't adjust it unless I completely remove it.. Any timelines on the covers?
timming chain cover looks good, those running verniers/285's etc will be able to change timming a lot easier
Would you be able to produce a set of rockers that increases the ratio, say to 1.7/1.8?
Originally Posted by Mart
you mean a bit like this
how is this done...making the end where pushrod is longer or shorter..
Perfectyou mean a bit like this
I will take one ASAP the engine won't be in for about another month.. This would save so much time and effort.. I'm not arsed about seeing the vernier through it just removable would be magic
Shorter - To increase the ratio, the pushrod cup would be closer to the rocker centreline.
High lift/stock lsa would make for a perfect stick, imho.
how much closer...2-3mm?
it's do able..just need to know what you want..lol
is there not a problem with it getting to close that the rod will rub on the head where it goes down to folower
I will take one ASAP the engine won't be in for about another month.. This would save so much time and effort.. I'm not arsed about seeing the vernier through it just removable would be magic
it not be clear...just like that on image...would be alloy all round...as for when I can get one made up...Ill let you know over wkend..
the second batch of roller rockers...almost ready for anodizing and then bushes and bearings..happy days
I'd have to measure, unless someone has calculated it before?
It might rub depending on rod angle, but the bore could always be opened up or elongated slightly - There's a fair bit of meat present in that area.
I agree...so something like this is whats wanted..the 7.5 is standard...could go up to the 9.5 or even more..
Great to see development continuing on the C1J. I would love to see a few more pics of the Roller Rockers fitted to the Cylinder Head.
Great to see development continuing on the C1J. I would love to see a few more pics of the Roller Rockers fitted to the Cylinder Head.
Here just 1 more for now..
great work, its a shame these little beauties get covered up.
have you got prices in mind yet?
Sid,
They look great and I'm interested in a set for sure, but like Mart, an increase in ratio would almost definitely be worth some gains.
Please let us know when you have worked out prices.
the price for a set of roller rockers is £240 deliverd...
I will have 14 sets to sell mid march...although i do have a list of foke that want them..so after them I reckon there is still 8 or so sets to go..as for ratio sets..maybe look at them in a few mth...got other projects I want to finish first..
Cheers sid :-)it not be clear...just like that on image...would be alloy all round...as for when I can get one made up...Ill let you know over wkend..
can we start a list of people who want them?? id put my name down for a set
Yep, something along those linesI agree...so something like this is whats wanted..the 7.5 is standard...could go up to the 9.5 or even more..
I'll work it out over the weekend, unless you'd be willing to knock up a few single rockers, with different spaced holes, and measure the valve lift that way?
If need be, can you fabricate alternative length pushrods? I'm guessing that by altering the ratio, it might also naturally shift the valve stem sweep position?
Might just be easier to fit a hotter stick
with the ratio rocker sets mite do a mid piont back end ...a bit like the bottom 1 in pic...but not all way down...so can still use norm pushrods...although there are 2 lengths of rods you can get....bout 3mm longer than norm..
There's definitely a market for them - I don't know of any company, even in Renault's homeland, that's ever produced a different ratio rocker. The French lads would love 'em I reckon
Even a mild/'safe' 1.6 ratio should give a nice gain with a stock stick.
If you need a testbed engine, I'll happily help.
Either way, keep us posted
There's definitely a market for them - I don't know of any company, even in Renault's homeland, that's ever produced a different ratio rocker. The French lads would love 'em I reckon
Even a mild/'safe' 1.6 ratio should give a nice gain with a stock stick.
If you need a testbed engine, I'll happily help.
Either way, keep us posted
ok..Ive just had a look on the old pc program...the 9.5 1 in above pic will give a 1.74 ratio..ill look at making a set in few mth...ill keep you upto date when I get started on them..
Sounds like a good starting point
Cheers
Mart...here is the finished look...1.74 ratio..
Sid, 1.74 ratio rockers will definitely produce some recordable gains and like Mart has said, there is a decent market for these as nobody makes them currently.
We would obviously need to prove that they work on an engine with STD and up to Piper 285 camshafts, but this is an exciting development!
I would also say that the load on the pushrods is going to increase and as these are a known 'weaker' area, I think an upgrade would be essential?
Great work Sid.
Just had a look at the Piper Cams website to see what the valve lift gain would be with a 285 and the 1.74 ration rockers. The Piper website says that max Inlet Valve lift is 9.96mm.
9.96mm / 1.5 (to get the actual lift at the cam) = 6.64mm
6.64mm X 1.74 (to get new lift at valve) = 11.55mm
So 9.96mm increases to 11.55mm with a rocker ration of 1.74:1, that's a 1.59mm increase. While it doesn't sound like too much, you have to consider that the 'curtain area' has increased by a decent amount!
Looks good, Steven.
Woz, 11+mm lift may cause p-v contact, and would certainly coil-bind off-the-shelf Piper/Catcam springs.
As a minor aside to that, ~9.6mm is about the max, with a stock head, from a flow point of view.
check the cam wizard. Piper 390 is 11.25mm lift with no valve clearance.
That didnt cause interference
i used cat cams springs and removed the under spring shim. was just about ok when running bigger valve clearances.
you could get springs made by these guys: http://www.testedspring.com/home.asp
you need to specify all sorts of stuff though.- open length, closed length, wire thickness, poundage at certain compression points.....
Mart, all very good points. My calcs are very crude as they don't really account for the arc of travel. The real lift would be less.
It's also worth noting that the valve will be open longer at each lift point with additional benefits to achieving this with just a hotter bump stick.
Like you say Mart, it may require custom springs and/or recessed spring seats to get everything to work but with the right head it could make for a really interesting engine. May even reduce lag on bigger turbos?........
Sparks, was that with a 'blue' headgasket in situ though? 73.5mm head?
I'm sure I measured low 11.xmm as being max lift possible (with o.e gasket/head), but could be wrong.
Ok you guys do start to loose me a lil...with all this talkhowever...I have started work on a head spacer
...this would be made of aloy and would be any thickness from 1mm - 4mm...
The idea around the headspacer in the first place was because most heads have now been skimmed and comp chanber is getting smaller...this is not good for high boost...so the headspacer fits with 2 gaskets...like a sandwich.
would this help with any of the problems the high ratio rockers brings..
the second batch of roller rockers...almost ready for anodizing and then bushes and bearings..happy days
I'm an absolute noddy with this stuff guys, so I would appreciate help in understanding both what do these cool looking rockers do that the standard ones don't and why they are able to achieve better lift than just fitting a cam with the right profile?
Also, where do the the new gains come from that Woz is describing that were previously unavailable using other tuning methods?
Knowledge gratefully received
Trev, here's a link to some Rocker theory. It's Mini based but useful all the same.
http://www.calverst.com/articles/CH-...compendium.htm
The main advantage of running a higher ratio rocker is that the valve will be opened further earlier in it's cycle, although the total duration will remain the same. This is because the valve is accelerated faster.
What this also means is that while the max lift created may go beyond the max flow the cylinder head is capable of, it's (probably) still worth doing because of the gains made in the rest of the range up to the max flow (further earlier).
Faster acceleration means that there will be more pressure on the cam, rockers and shaft, valves and for OHV engines like the A Series and C1J, the pushrods too.
There is a limit to how far you can go with all this but for the C1J there is no data to compare?
Lastly, I'll state that I am no expert and that all my rocker ratio knowledge has been gleaned from my Mini days.
Sid, in the above article, Keith Calver states that 'needle roller bearings' are not suited to the reciprocal motion of rockers. So it may be better to stick with bushes?
Thanks v much Woz.
I picked up on this piece of text from your link that might be useful for other noddys like me here:
Cam goes round, lobe pushes follower up, push-rod transfers this to the rocker which in turn opens the valve. Simple. Generally the aim is to open the valve as long, as fast and as far as possible - optimised for any particular application.
A road car needs differing performance to a racer. This is pretty much governed by the ‘as long’ and ‘as fast’ bits and is established by the cam lobe profile.
The rocker then mainly influences the ‘as far’ part. The cam lobe profile and height generally controls how far the valves are opened at any point, but the actual and final amount is down to the rocker gear.
So it appears the cam is able to control how quickly the valve opens and when that happens during the cycle by way of the profile.
So changing the rocker ratio simply controls (increases in this case) the physical distance the valve is pushed open for any given point during that entire cycle?
If that's true, I'm still not quite sure why that 'actual and final amount' can't be achieved purely by correctly re-profiling the cam to work with the existing rocker ratio. As Keith states:
A change in camshaft will aid volume of consumption by holding the valves open longer, and/or pushing them further open.
Maybe the profile required would be prohibitive with the cam housing/casting?
Not that I'm questioning anything, other than to improve my own understanding
An interesting point at the bottom of the article:
<blah>....the lift developed by this set up can be too much, hurting power rather than improving - it’s rarely worth lifting a valve higher than the cylinder head's peak gas flow point!
Do we know where the C1J's peak gas flow point is?
For Sid to have developed these new rockers I guess it suggests one or more of the following two things:
1. that the peak point of gas flow on a C1J cannot be reached purely with a tuned cam and OE rockers/valves
2. I am dumb and am not understanding much
It can. That's why people fit hotter sticks
Essentially, with a larger ratio rocker present, it's the same as increasing the lift of the cam.
From our point of view as well, with a C1J/ohv engine, it's a flaff on removing/re-fitting a cam if the head is still in situ, and/or the engine is still in the car. Changing the rockers though is relatively easy (in the same way that replacing cams in an ohc engine is easier), and although it's maybe seen as 'inferior' to fitting a hotter stick, the potential results/gains probably won't be that far off, imho
If only we were blessed with dohc, or a mivec/vtec 'esque setup...
Yep, I mentioned that above.
Oop, sorry Mart, since reading Woz's article, it might have been a good idea for me to then re-read the thread to that point to consolidate. Have done so now and it all makes a lot more sense. Thank you.
So for my own sake; the reason for doing the rockers in the C1J is to mainly to make it easier and cheaper to increase lift throughout the stock profile (and with the addition of the roller, eliminate any side load there may be).
I guess, as the others are discussing, changing both the rocker ratio and the cam will need some additional thought. How have the ratios being decided upon for this first batch? Has there been some testing with the stock cam prior to that first batch being fab'd? Or do they come with a stock ratio? Also, is it possible to adjust them to alter the ratio slightly or is the adjustment simply to set their relationship with the rods?
What is the added value of the sleeves on the new rods btw?
Last edited by Trevhib; 25-02-2013 at 15:48.
Mart - tbh i can't remember what my comp ration was - the head depth was definately less than 73.5mm
however another problem popped into my head.
- the hole the pushrod goes through in the head, may need enlarging slightly, as i'm pretty sure with that 390 cam, i ended up wearing grooves halfway up the pushrod, due to lateral movement of the pushrod on a particularly peaky cam. - i think the increased ratio rockers might make this worse, as you will be moving the pushrod to one side slightly.
worth checking?
At least you saw my posts; 99% of the time they're invisible
Yep, pretty much as you say, plus, imho, I think a stock stick with increased lift will make for a good all-rounder, even on the larger turbo setups. But again, I could be wrong
No ratios have been decided upon yet, unless 'Sid' has already worked out what's what, plus I guess he'd be the only one who'd know how much meat there is on his roller rockers to allow for moving the pushrod cup closer to the centreline.
It would appear that 2mm closer equates to a ratio of 1.74, so on a stock cam that would give a 1.2-1.3mm increase in valve lift & a natural increase in the curtain area (as Woz mentioned before). That's a good start I reckon
As for sleeving the rods, that's simply to increase their (lateral) load threshold.
Another one of those invisible posts
So by increasing the lift your moving the optimum engine speed regards inlet and exhaust up the rev range, hence hotter cams working better with bigger later spooling turbo's and increasing the engines capacity to breath, so how does overlap work? and is overlap (when both valves are open at the same time) more advantageous on a turbo'd engine?
I'm presuming however you increase lift this will always increase overlap?
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