Hi guys, sorry if this has been coverd above, i have looked through them and seem to find myself getting lost, there litteraly is too much info on there for me So basically i have bought a 2.0 16v 9A engine for my mk2, i will be running this on standard kr k-jet managment meaning it is plug and play pretty much as far as the loom, ecu, tci etc etc go (its currently a 1.3) ive been told by the guy i bought the engine off that it has a kr inlet cam as the standard 9a cam is very restrictive (i am yet to check for deffinate) however ive been doing some research and have noticed alot of people fitting the full kr heads onto the 9a blocks, i presumed these heads were the same however i must be wrong? can anyone explain to me what exactly the advantages of running a kr head on a 9a block is? is there any difference apart from the inlet cam? the reason i am asking is because i have a kr sat in my garage doing nothing so while the engine is out the car i can swap the heads over IF its worth it oh and while im here, can i ask why its so hard to find a full K jet fueling setup for sale including fuel lines and wiring?! been looking everywhere but nothing decent has come up Cheers, Christian
You need to check the two heads casting numbers to see what you have got. Numbers are just above no1 inlet port. 027 103 373 is the head with narrow section between the two inlet valves in the inlet port. 051 103 373 is the later head that has a fatter section in the same place. Basically fitting the KR cam is enough, no need to swap heads. The 027 casting will need the locating dowels on the block dressing down when fitting to a 2.0 block as they are in a different location on the 2.0 and 1.8.
OK thanks for that mate, i will have a look when im next at the garage and compare the two. I also need to check the part numbers on the cams as im not 100% weather it is a kr inlet or not. so i wont see any gains atall no matter which head i have? i just wonderd as a lot of people see to be fitting the kr head onto the 9a block
Jus swap the kr cams into the 9a head. If anythin the 9a will have the better head (prob an 051), but the kr has the better cams. Think the kr cams had 027 stamped on both, and the the 9a had one 027 and one 027* (can't remember the suffix letter).so jus put both the 027 from the kr in. Better still use an abf engine from top to bottom.
Unfortunatly when i bought the 9a i didnt realise how much better the abf engine is, however if i break the 150bhp mark i will be happy. ive seen people get 170bhp from their 9a's with only kr cams, 4 branch manifold and a few other little mods, oh and a good tune up. are all the exhaust cams the same? i dont wanna swap it out if theres no point!
My 9a with 9a head but kr cams made 158bhp on the kjet etc. Then the crank keyway went, so I chucked an abf in there, on the same kjet same setup literally 3wks later it made 159.5 bhp on the same rollers.. So marginally better. The 9a definitely had more grunt lower down tho, the abf pulls v hard above 5k rpm/100mph in 5th tho, prob where it performs best overall. But from the little of experience I've had with these engines my 9a/kr cam felt best- but there are a million things to factor in (high/low mileage,general internal conditions of both,maybe got a brill 9a and a not so good abf if ya know wot I mean)
yeah i get you, thanks for the info there. i spose the 9a will rev better as it has a shorter stroke. is it a common thing for the crank keyway to go? ive heard of a few doing this :/ was that the only mod? the kr cams? i have a 4 branch to go on and hopefully a lightend flywheel soon (i know this wont affect bhp)
Yeah that was the only mod, everything was standard kr - exhaust from manifold to tailpipe, 50mm inlet, complete kjet system, 02y gearbox etc etc. Same on the abf. Am yet to set fuel pressures on wur, as its all off the kr and not been checked in years/ever, so hoping for a little gain there maybe if its set up bang on all over.
ok then, quite a difference just with the cam then! i need to measure the inlet too, not sure weather its the 50mm inlet or not, thanks again for the info
My 1.8 kr had the 50mm, and my 2.0 9a had a 42mm. Am tempted to 1 day put the 42mm on, to see if it improves lower down power without compromising top end too much. After all I've got it the opposite to how vw intended I suppose
The main performance difference between pre 94 9A and KR is the intake camshaft only. The difference in 027 or 051 head casting is negligible regarding std performance.
Do a lot of people experiment properly? 9A head and block + KR inlet cam = similar power and torque as a STD digifant 3.2 ABF. The power values seen around here are elsewhere vary. This was written comparing good working 9A with mappable system vs Stock Digifant 3.2 ABF vs ABF with mappable system. Read carefully to understand what is taking place. All vehicle were driven prior to testing, tested and developed by me.
All this talk of ABFs being "far" better than a 9A is nonsense & largely irrelevant for 90% of folk going for a mild state of tune A 9A with kr cams run on kjet will perform very very similarly to an ABF using the same fuelling and ignition. Run a 9A block using kr or ABF cams & digi 3.2 management and once again they will be similar Run either block with appropriate fuel and spark control and the results will be very similar again. Both engines have the same swept volume and compression ratio so the hardware is very very alike. Worth noting 2 of the very strongest k jet 16v motors I know of are circa 190BHP (real world figures) using 9A blocks and flowed heads with schrick cams & revving to 7800. These cars were a match for my DD proven 193BHP 9A ITBd 16v in a straight line (along with the twisties at Combe). Both of said engines were built by TSRs former workshop manager...
There are lot of engineering facts to suggest the ABF engine is an improved version of the older 16v range but that is covered elseware. So its not just talk... The torque generation is different between the two... Regarding the differences to the above heads 027 or 051 on a 9A regarding the OP quest for more nominal performance very little difference on head differences per se. So no need to strip the old KR. Yes agreed for a nominal set up. Although you only need the intake cam for 051103373 head, the exhaust cam is the same for 027 and early 051 heads. Shows that you cannot rule the good old 9A given a suitable budget.
stock 027 is better flow on intake than 051 http://web.archive.org/web/20041205190856/www.scirocco16v.com/tech/faq_18v20.htm but ported heads are similar
wow thanks for all the info, im not aiming to spend hundreds of thousands, just a nice OEM setup that works best and is proven, it seems the inlet cam is the only thing needing to be changed, thanks again for the info, very usefull
