Good info there, regarding my airbox, I really don't know it's worth yet, it was only added to help reduce noise primarily (athough its not done a great job there!) and with a hope it might help the engine breath. In reality, RobT had one fitted and it strangled his engine so I do not and have high expectations for mine, I do want to see for myself what it is doing and will at some point validate it in one or two ways. I will sometime in the distant future seek you out to purchase a set of cams, but, this will be some time off. I'm enjoying far to much the moderate power my std ABF and bolt ons are producing and can only dream what 249bhp valvers are like!
Nice one Jason . What was the motor giving before hand, was it in any state to test, had it been on Vinces rolling road? Would be interesting to get it on there now and see how it compared to AP's Engine dyno output, just for reference. Have you heard from Ian how it went on the rally the other day?
Not so much a new development but.... On behalf of Paul & myself, I'd like to wish all of JMR's customers & supporters a very happy new year and hope you all had a great Christmas. Thanks alot for all your business in 2012, be it an engine mount to an engine, your all thought of the same. From road cars to hillclimb's & sprints, to circuit racing and rally stages, we've enjoyed every bit of our involvement during 2012, and with the workshop & order book bulging at the seams the start of 2013 looks very bright indeed...we will even be out and about pushing the pedals & torturing tyres ourselves in the new year... Best regards to you all and best of luck with those projects out there...and looking forward to catching up with those I haven't quite got to toward the end of this year...you've not been forgotten. Happy new year! Jason
Keep up the good work, Jason. All the best for 2013 - hopefully that X-flow head will breathe new life into my Scirocco in the near future!
All the best to the west! Thanks for the effort put in on mine and hope 2013 is bigger and better Tim.
Thanks alot chaps! Yr more than welcome Tim...welcome to the JMR family! Hurry up and get that head on Mike! Cheers Sam......good to talk earlier...catch up again soon.
We're looking forward to seeing this on Motors TV during 2013!... ...to be found on the class B contender of Nick Penfold. We supplied Nick a block assembly & cam engine last year after his old unit got a tad smokey, and with a suspension re-vamp and some weight lost (the car not Nick!) this year, the MK1 should be mixing it up in Nick's hands. The first round was cancelled from this weekend due to snow (honestly!), but is due to be re scheduled...we're very much looking forward to seeing Nick's progress while carrying our first national sponsorship and will be reporting on his results.
Going back to the crossflow head part of this blog, have you looked into a larger exhaust valve? Say the usual 35mm upgrade for the counterflow heads?
I have supplied Jason with 35mm Supertech exh valves that will be going in to one of the x-flow heads he is doing for me, new valve seat inserts required to do this so it will be for the future iteration of my engine.
Whats the usual cost for installing 35mm exhsust valves. And is it really worth it in terms of flow gain compared to the 33mm valves.
I maybe should have added that I am only going to 35mm exh because I am also going to 42mm inlets....cost wise you need to factor in the cost of the valves, new seat inserts, machining to fit new inserts and then the necessary porting work to make use of the larger valve size. Jason is best positioned to answer the other questions,
IMO there isn't much to be gained by going to 35mm exh and keeping with std inlet size, although I'm sure some people will disagree with that, so no it won't be that cheap I guess....I got my Supertech valves in the US and had someone hand carry them back in their luggage which saved a fair few pennies!
It's interesting... 'bigger exhaust valves' has long been the accepted wisdom in tuning VW 8v heads, and I've been as willing to repeat it as many people, but you wonder if any research was ever done to prove it, and the reasons may be lost in the mists of time. Jason's investigations don't seem to bear it out, so why did GTI Engineering / TSR / et al even bother? Maybe they just found a cheap source of 35mm exhaust valves and seats (for example, maybe they were standard bits from another manufacturer), thought it was a good punt, and it caught on? Maybe there was a more scientific reason for it? I'm going from a counterflow Pack D head (40.5/35mm valves) to a X-Flow (40/33) so we'll see if the smaller exhaust valve actually causes a problem. I doubt it, but time will tell.
When do you think you'll have the engine up and running Mike? Did you see my PM & email about it the other day? Tim
