If anyone misunderstood my last post I will say it simpler......Cant we all just get along? Now let's please have fun talking about our minis.
All this talk of rules & such makes me wonder if I've somehow gotten into the sewing site by mistake. We've gone a very long time without needing a rules refresher. What has changed?
This thread is actually a discussion on "wants" and "needs." If I wanted to go really fast then I would have kept my LS3 Corvette, a nice yellow one that I bought from Dale Earnhardt Chevy, not Junior, who did own a MINI at one time. I can do allot of different stuff including turning a wrench on my car but I am more comfortable cutting wood than metal. This means chopping the frame up so I could put in a different larger engine is not going to happen. So back to thinking about squeezing a little more power out of the Tritec. Of course squeezing should really be "forcing more air through the motor." I have done the simple bolt on's such as pulley, cam, header and tune but to get much more, the forcing more air issue comes into play. The wants and needs also plays into the equation. Now I have the money to go with the biggest and best but this "need" thing keeps popping up. I am also frugal so after I assess my needs, I research and the number of Ben Franklin's involved are looked at very closely. This same logic, some might call penny pinching, led me to my just over $300 meth injection system and my just over $500 Brembo brake package. So, I am back to the Thumper head. What is interesting is that his TPR1 head that is only ported/polished can provide approximately 25 WHP +/-. Comparing the costs of different heads there is an approximate $50 per one horsepower of gain ratio. This is the head only and does not include labor, the other parts involved or a tune. The RMW head has greater hp results and is actually a little below that $50/HP number but for me it is back to what my needs are, not my wants. A MINI, any MINI is a great handling small car. For me being an old fart with hips that have seen better days, it is easy to get in/out of and with my 6-3 frame it has plenty of room. My flying pig is much more fun for my driving habits than the Corvette was, and, by spending some of kids inheritance on a Thumper head, my smile might be just a little bigger. That is of course if I remember tomorrow what I said today . . . . . . . .
I have not gotten to the point that I cannot remember what I said 5 minutes ago, but that time is coming.
I have a R52 JCW - RS. A very special MINI that handles better, goes faster and stops quicker than any GP1, plus it has a drop top. Don't worry we that have drop tops still associate with you that do not.
I think the biggest issue with the Thumper products has been in the past very spotty quality. Seen some images of some very scary porting jobs and the comments from folks with a lot more experience than me have not been encouraging. Seems to me that old school hand porting is really not the best way to go.
Hand porting worked for many years, yes a computer controlled machine is going to be more precise and steady but if that it is all life is about than the likes of Shelby, Foyt, Yates, and numerous others that were mechanics such as the guy that created the below, mean nothing. For me, just because something is old or is produced by old means/methods, does not mean it is worthless.
A TPR1 seems perfect for my lower redline auto but this, and the possibility of dealing with an issue across the country, is why I haven’t bought one yet. How much do valve size and porting affect each other. At the end, Cosworth sold some of their BVH before completion with stock valves. Does a CNC’d head work if the valve part is skipped, or would the contours of the intake and exhaust porting have to be redesigned?
I think this really depends on the desired outcome and machinery. For some of my cars, the 88M5 in particular there were not really any options. However there were a number of folks who did the work. The two most predominant (and IMO best) had a full set of jigs specific for the head and produced consistent results and gains. Granted they had both worked for Factory backed BMW teams. Now, I do think the bigger question is the difference between a head that is developed on a computer and flowed for specific outcomes and tested heavily, that should almost always create better results. It would most likely be more consistent also. That said, I would expect it to be more expensive per HP (Design/machinery cost etc). I am kind of surprised that both are in the $50/HP. For me personally, it's not just about HP it's also about Torque. Euro engines (at least my old school ones... especially the 88) the torque and HP came in at the top of the range. Getting more HP while expanding the Torque curve helps a lot. One way we do it is to change to shorter flutes and mating them to the side of the intake plenum. It makes a significant change in the torque curve at very little cost.
Old school hand porting was ok because everything was hand controlled with a carb and a screwdriver. In today’s cars everything is controlled by sensors and ECU’s and hand porting will never be as good or as consistent as CNC’ed flow tested work. Also you can make many more changes with a tune than you can with a head. It’s all about where you want you power curve to be. I can can tell you this, Shelby, Foyt and Yates would ALL be using CNC machines and today’s tech if they were building motors for a car with a modern ECU. Why work harder and not smarter? That is what the MINI is, a modern car. This would be a different story if you are hand porting a head for a classic Mini.
Agree with everything said and if I was looking to compete with my car I would go the CNC route. There is a cost difference and with the TPR2 head, a ported intake manifold can be added and the total is still less than the RMW. When I start a thread it is not a "this is what you should do" but rather "this is what I do." Anybody wants to go the CNC route, have at it, no problems here at all.
On my X 1/9 I did the port and polishing. I had a machine shop with lots of experience building drag engines put in the big valves. They looked in their catalog and found valves with the right length stim hight and the size I wanted. Of course they had to put in bigger seats but they did a great job. Some 15 years later I was in a shop talking to the owner and he said he had an X 1/9 with BVH. He had never seen one like it, I walked out into the shop and there sat my old car. still running. So anyway......The JCW head was ported and polished, if I remember right I am old, have you looked at any local machine shops that could put in the size valves you want? Find one with experience with race engines.
A JCW head with the valves you want done by a good machine shop that does quality work will be better then a poor quality hand done head by anyone. Sorry but Thumpers heads are not that good and have not been for many years of reviews and failures on MA and NAM. It’s just common knowledge that they don’t hold up and are worth the time and money. Now with all that being said you can always choose to ignore years of reviews from owners that have and go down that road but be careful not to mess up your motor.
Ok - before we go further down this discussion, there have been many like this in the past. Here is what I think is a summary: 1) I think most people agree a CNC head will most likely be better than a machine shop and/or hand done head. Your mileage varies. I imagine there are exceptions to this but overall appears logical. 2) There is a cost difference and potential quality between the two scenarios. In this case, that weighs into this and it appears he feels the head will meet his goals. 3) @BlwnAway is still happy with his decision and has a very nice build going. For those who have not seen it, here it is: https://www.motoringalliance.com/threads/hit-a-milestone-and-still-making-changes.14654/ Like in that thread, there was a similar discussion. If @Whine not Walnuts chooses to go with Thumper or someone else so be it. Glad he made a decision and opinions were expressed. Personally, I look forward to seeing the outcome. It would be cool to see whomever he chooses make the head, but I'm not sure if that builder would have interest in that. Some builders want to keep their "special sauce" to themselves (this is anyone, not just Thumper etc) some don't. I understand both sides. I'll see if I can dig it up, but there was a video of one of the builders for the 88M5 head I mentioned earlier that showed the head build. Was pretty cool with the jigs etc. @Whine not Walnuts - you have any goals or outcomes in mind? i.e. HP/Torque etc? Timeline?
My thoughts behind using the JCW head was if you were looking for the best bang for the buck that may be one avenue. I don't know if the ports match your headers though. I If not and it has to be ported also there won't be much savings going that rout. This thread is making me want to keep my R53.
OK a couple of things. 1.) The JCW head does have enlarged exhaust ports but the intake ports are not. I am looking for my flow data but thinking the normal S head is like 100 CFM, the JCW head is 118 and the RMW BVH is like 180 CFM. CFM = Cubic Feet of air per Minute. 2.) I will not be doing the head until after the first of the year. I will ask Thumper if he will provide some pictures during the process. 3.) From dyno data I have found on the web the head along with my other mods will be in the 230 to 240 WHP range and a 200 range in Torque. As it appears the drivetrain loss factor for a FWD car is around 12% that would be around 265 BHP. Not bad for a 10 year flying pig.
All this discussion leads into more detailed discussions on the head, valves and camshaft. I created a thread that has some basic information on these engine components along with some web supporting articles and videos. https://www.motoringalliance.com/threads/talking-heads.30840/#post-408729