Aboslutely, Bargate's is lovely and in a rocco! But very few VWs in rallying unfortunately. Consistently humped by old iron block pintos in mk1s and 2s. This is ok though. [YOUTUBE]NknCBsffiSA[/YOUTUBE]
There are many "poorly" modified 2.0 16vs indeed that would struggle to get to 170bhp and 150lbft on the 450DS dyno I have been using, but my point is still an 8v is limited and can get expensive to match a well sorted but STD 16v engine. The 16v engine that was used to compare is a std second hand engine from a Seat. The engine was never not opened and the car is driven daily. I have and actually hats off to Geroge HH for wanting to build such an engine. And he did keep costs down. But he had to open the engine and perform an head swap to only match the performance of a stock 2.0 ABF. Again assuming that dynos are comparitive, which I can assure will not, unless a corrolation exercise is undertaken, here is a plot of George's data compared against Dav's STD OE Digi ABF. Assuming transparency, this would be a case that all "152bhps" at not created equal and the 8v is down on torque possibly due to the need to be mapped. But so is the 16v...Still in the end, even with the dips taken out , it will be an 8v but a faster one. In this example we not even talking standalone PCM. How much time does it take to swap an engine, then a head and cams and still you need to optimise controls to only sort of achieve part torque curve of a std Digi ABF engine. No becuase this is a separte discussion. To all please read below: *** For the purposes of discussion I have chosen to combine plots, to observe torque profiles. This however is not a subsitute for proper controlled comparison ***
Costs please Eddie? You need to source an ABF, you then need to either install it with k jet (you dislike and harder to get all the relevant bits in good condition too), therefore it is a loom change to run it on it's own "limited" ecu, or you buy MS and go through all that is involved with that, both in time and costs. It adds up to be pretty expensive. Opening the engine? Come on, a head gasket job and decent head skim when it is off to up the compression so as to match a 100 second hand fast road cam. George's head isn't even ported. Hardly the same cash involved as a full ABF MS conversion for a very similar result.
You choose George and I choose Dav's 16v. Both with skills and resource to keep costs down. So that is zero'd. Both running MK2 Golfs. We are not talking standalone so you can also zero that out. Dav's engine is proper STD from a Seat and that is the curve since performing the conversion from his 8v digicrap thing. 2E 8v = 50 quid X flow head plus head skim, Second hand cam and pulley 100 quid unknown costs? Complete ABF digifant = 300 quid w/ECU back when the how to thread was created, less now. You can pick up a head and block for 150 quid if you know where to look. You also have a base engine that will intellient tuning can achieve 160lbft+ You modified an 8v which by this unscientfic comparison only came close that of a boggo std complete factory ABF engine. A bit more torque from the engine Wippy described, using the same dyno assumption, which in fairness may have an issue post 4500rpm that may affect the entire profile. If paying out to do this the ABF conversion is still worth it and is expected to perform at leaset close to what the was shown in the plot from Dav's car. So is it worth it? Or even when does it become worth it?
Is it worth it? Who knows when everything is taken into account. But what the "worth" is should actually be clarified. It may not be headline numbers after all. Some folk's choices should be respected rather than dismissed or made too look like a bad choice. That zippy748 dyno plot was put up on here by someone that knew something was wrong and was after help to work out what was wrong. A very poor thing to use as a comparison IMO. Using anyone's half done or unfinished work as a true example of what is possible is a little off the mark. It is not "all in the mapping" if there is something mechanically miss matched. There is a fortune tied up in that build by the sounds of it. Money wasted if the incorrect specifications of parts are selected. Same way money can be wasted on 16v engines too. And I would have thought final drive is very relevant if concerned with making a car accelerate fast.
As the owner of a std but optimised 2.0 8v I know all to well that OE 8v engines do not like to breathe post 5500rpm and drop torque off like a stone. Both 8v engines in this thread by their profiles have done well in this respect. My MK2 3A 8v pulls hard, but will never be an ABF that will have good VE to near 6500rpm then drop off. I know other members on here with strong pulling 8vs that would put a smile on any 16v owners face as well. All have a very similar characteristic. And it would seem that the X flow units change this pattern very slightly by shifting torque towards the middle at ~4400rpm. Showing wippy's work and comparing it to an unmodified engine with more natural rev range, though std, puts into perspective what that car would feel like and where the issues are when the car is in a WOT condition. In my experience, its an 8v and the top end of that torque plot will remained largely unchanged. Gearbox aside still a strong pulling engine. George HH, another example of a strong pulling 8v engine with a cheaper build theme. It takes me time to compile these comparisons too and the truth may hurt when they are finished. It does stop the "easily make 200bhp" or chasing numbers nonsense when the physics or torque profiles say no, not at this rpm, please spend more time and/or money! So is it worth it, when there are other 4 cylinder factory solutions waiting to be transplanted?
Well there you go then. You state that your 2.0 "short block" (considering similar 9A / ABF recent results ) 8v toils to breathe at the top end on a counterflow std head. Initial flow test show that the std crossflow head flows almost as much as a full race spec counterflow head. The fact that nobody has actually got round to building an optimised engine is the issue here. I know you are a good guy and can see all the effort you put in to folk's cars. I am just a little surprised that there is never the same interest in a positive way towards assisting the lesser valved models on here. Even at the start of GeorgeHH's build you mentioned a few things that were not correct with regard to the oil drains. But as you are a recognised "geezer" on here, it will put some folk off when they hear you say something like that. Hey, I know we are all human and make mistakes and errors though, eg. thank you for quoting my incorrect TB size in the super 1600 single plenum post. It just seems a little odd coming into the thread so late on with an view that is not exactly based on any firm specifications, when you are generally such a stickler for the details. I mean, comparing dyno sheets from different businesses with no AFR and compensation details. All good banter Eddie.
Its all down to the owner really. Im going for a crossflow as i like the fact that it is sort of original in repect that mk1s were 8v from the factory I dont really think anyone is trying to claim the crossflow head will outperform the 16v? With the ease and cost of swapping the crossflow head onto an 8v car, i dont think you can possibly say it isnt worth it as you pointed out toyotech, a crossflow head with manifold will set you back about 50 at the moment and once checked over/cleaned/skimmed if necessary, would take maybe a day to install onto the current engine. however you look at it, its going to be an improvement over the stock counterflow compare that to buying an abf for 250-300, checking it over, spending 30/50/100 servicing it then spending the time installing it. i dont know how long that would take for some of you more expeirenced guys, buy my mk1 g60 swap took me over a month albeit only working on it in the evenings weekends If time = money, then you cant pretend its not cost effective to do a crossflow head swap
Well I started this thread to determine whether it was worth going Crossflow from counter flow on an 8v, in terms of lower inlet temps, better flow over counterflow etc. I've always put off going 16v as I have a rebuilt 8v bottom end that I don't want to ditch in favour of a 100k miler abf 16v that I will need a new exhaust manifold, the only one worth gettin being a super sprint at plus 400, it would be sensible to have it rebuilt so that's another good few 100 's just in parts let alone labour costs. Then there's the fuelling and ignition side of things, in order to run it in my mk1 as it is now I would have to run it on MS which means a MS ECU and loom then mapping etc. By the time I've done all that I could have the 8v I've got now to a more powerful state most likely.
Yea but you have a problem with very low CR ratio, I'm looking for a CR of around 11.25:1 to suit my cam. Not sure if I could take enough just off the head to get back up to that kind of figure. I got a feeling there will not be enough meat on the head. But that if for another thread.
You are jumping around the place Dan. My 8v 3A counterflow peak torque at 3000rpm, George 8v cammed X flow peak torque at 4000rpm, Stock fettled ABF 5500rpm. And yes I do get things wrong and am willing to admit that but what you have sited has nothing to do with this thread of "is it worth going Crossflow?". I have put in bold the assumptions regarding my comparison so no need for me to get specific as this is not a controlled comparison.
I am not jumping around at all. You are basing a comparison on the counterflow head on your own car now. IT IS NOT A CROSSFLOW! The crossflow flows a lot better than your std counterflow head. Forget about it, I really do not care about it any more. You do come across with a very blinkered outlook on things sometimes. You have know idea that the zippy748 engine may have very poor compression or duff cam timing meaning it is down all over the place. There is no data for you to prove anything with. Maybe the dyno was having a bad day?
But isn't this turning into an 8v vs 16v thread now to go with all the other 8 vs 16 threads. Were trying to determine if there is an advantage of going Crossflow over counterflow. Every1 knows that you will never get as much power out of an 8v for a cheaply as you can with 16v but this is not the point of this thread.
The ABF engines that have been shown on here are not rebuilt and are running less than std loads, due to them placed in a MK2 or 1. Supersprint exhaust not required to achieve 160PS from a factory engine. You do not have to run MS and can run a STD ECU. To run a crossflow you still need to optimise it with mapping anyway if increasing compression, replace cams and headers. I can see where you are coming from in terms of cost as you already have the botton end already and want to get your money's worth from it. You would have a more powerful 8v than a basic 8v engine, yes, but not anything near what a fettled 16v ABF would be if the same time was spent on it.
MK1 platform needs specific 16v exhaust manifold In GeorgeHH's thread the first thing you say is that the 3 rear oil drains need blocking off which is incorrect, so very relevant to the "is it worth going crossflow" question as it means more work. Not true. Header does not need replaced. One cam.
