A&Q about 350Z
Q:
I've noticed a few different part numbers on the 16V heads. I have already spotted part numbers 051103373 and 027103373E .
Does anyone know if these heads differ in chamber design, is one head better then the other??
A:
I've noticed a few different part numbers on the 16V heads. I have already spotted part numbers 051103373 and 027103373E .
Does anyone know if these heads differ in chamber design, is one head better then the other??
I wrote this the other day on Edition 38
1.8 heads have better intake ports (051) and (053) heads have better exhaust ports.
There are 4 16v valve head castings.
051 103351 KR,PL NB the KR,PL and ADL are all 1781cc the rest are 1984cc
053 103351 6A,9A and later KRs
053 103351B ACE,ADL and early ABFs
053 103351C ABF and Late ACE
Early Castings 051103351, 053103351 1986-1995
What makes the KR the most revvy 16v all other factors equal, is the intake cam which is 027 109021AH which has extended duration compared to the cams found in the PL,9A,and 6A which is 027109021AL. The exhaust cam is the same on all of these listed as pt# 027109022G.
Later Castings 053103351B, 053103351C 1992-2000
Again the ABF was the most powerful of the lot part due to the intake cam amongst other things. I got the part no as 051109021B for the ABF motor where as the rest including the 1.8 ADL engine used 051101921C for the intake cam. Exhaust cam on all was listed as 051109022B.
I have never been able to compare valve sizes between the various heads but careful study of the part numbers shows that KR,PL and 6A motors have the same inlet and exhaust part numbers of 027109601C and 027109611B respectively and the other engines got 051109601B for intake and 051109611B for exhaust. If any of you know more data about this pls dont hesitate to correct.
Hope my 2p helps.
A:
Thanks a lot for sharing.
So if my head is a 027103373E, that makes another 16V head to add to the list.
What we need is a flow bench and a couple of heads to compare.
A:
Just to add to this, the head I took off my 6A engine last week appears to be a 051103373 which is the same number as the flowed head I put on. I thought KR and 6A heads had a different code as above?
Perhaps the head I removed wasn't in fact the original 6A head but a KR one as I bought the 6A engine complete and ran it as it was for a year or so, could have had a head swap previously? Just wondering if there's a difference as I intend to sell the spare head so could do with knowing exactly what it is
A:
Just to add to this, the head I took off my 6A engine last week appears to be a 051103373 which is the same number as the flowed head I put on. I thought KR and 6A heads had a different code as above?
Perhaps the head I removed wasn't in fact the original 6A head but a KR one as I bought the 6A engine complete and ran it as it was for a year or so, could have had a head swap previously? Just wondering if there's a difference as I intend to sell the spare head so could do with knowing exactly what it is
Stu, It might well be 051103373, with no letters following, if the KR was a late one.
I went in the back of the house last night. I got 2 1988 KR motors one 1994 ACE and an ABF. Checked out the heads. The KRs had the 027103373E heads, as said by Xiotis, and the ACE and ABF had 051103373D heads. I will add these to the list on the top but I believe it does not change what was said in principle. The only difference I saw between engines was the ports.
DarrenE is very good when it comes to UK part numbers. The list I generated was from which seems to have the last 3 digits different '351' followed sometimes by a letter. If you were to substitute this with the numbers we have on our engines here you will see the same pattern emerging.
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Just an update on this 16v head part numbers question.
The numbers that end 027/051/053 *** 373 refer to the part number for the complete head with cams valves springs etc and NOT the casting. I comfirmed this with VAG. So you can feel free to use the info I supplied about the castings part nos which end *** *** 351 and apply them to your code of engine.
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Good thread here guys - FAQ material...
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Good thread here guys - FAQ material...
Sticky as you please.
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Now in Engines FAQ section, but thread left open for posting.
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Moved back to main section since people couldn't post when it was here (looking into that)
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from what I can see on ETKA another difference between the early and late heads is the valves, and this is not specific to the ABF/ACE it's based on chassis number and means late 6A/9A's also have the same valves as ABF's.
The change is chassis No. 50-P-008 000 onwards. Top spring disks and split cotters change too.
I don't think it's valve diameter that changes though, there's not enough room in the combustion chamber.
A:
how about some flow bench numbers.
Lee
A:
Dont know if this helps but KR heads have 28mm exhaust valves but a 27mm seat.
ABF heads have a 27mm exhaust valves and 27mm seat.
A:
Dont know if this helps but KR heads have 28mm exhaust valves but a 27mm seat.
ABF heads have a 27mm exhaust valves and 27mm seat.
You are correct as I done that measurement myself and was discussing that last night with a buddy of mine. This means that the abf engines's exhaust i.e. valve and port will flow better. You will find this size valve on the ACE and ADL engines as well. On my piont about lift, the chap I was talking to said to me that he once turbo'd a 2E 8v block with a 16v head. A complete KR head was used and this was fine for a while. Then he went for an ABF complete head and this was damaged when the motor was on high revs as all 8 intake valves crashed with the pistons.
A:
from what I can see on ETKA another difference between the early and late heads is the valves, and this is not specific to the ABF/ACE it's based on chassis number and means late 6A/9A's also have the same valves as ABF's.
The change is chassis No. 50-P-008 000 onwards. Top spring disks and split cotters change too.
I don't think it's valve diameter that changes though, there's not enough room in the combustion chamber.
Interesting on the spring retainers and valve collets. Only problem is...
Why would the difference of the early and late 16v heads be down to a chassis number on a 1994 "P" Corrado "50"?. The the first public ABF engine code was in 1992 and was in a "1L" Seat Toleado. This would have had a 053 *** 351B head casting. The valves on headcasting 053***351B/C have the same part nos and are different to the valves found on early 051/053***351 headcastings found in the KR,PL,9A and 6A cars.
As far I can see the 16v Corrado came with a 9A motor and the head used would be casting 053103351. But when you look at the part nos for the complete head which is denoted by 027/051/053 103 373 this is where you can have changes to head components like what you mentioned by placing a letter after the number. If VAG did carry out a modification to an engine component and not change the engine code those cars will be updated in the parts list from the chasiss number and year the revised engines started to be installed.
I am interested in that infomation on those spring retainers for the 9A and will look into that a bit more. It might well be they used a 053******B head with the 97.5mm length exhaust valves on the 9A from that year and chassis number. I will search and see
A:
Hi,
With regard to the KR heads that have 28mm exhaust valves but a 27mm seat, could a 28mm seat be fitted for extra flow? I know the space in the 16v is limited for fitting larger valves but just wondered if increasing the seat size would help flow?
I'm going to be stripping a PL coded 16v in the coming week or so and I'll post what head number I find.
Regards
Mart
A:
hi
this may be a bit on the late side but a good way to help flow on the 16v head is to remove the ridges and edges left by the manufacturer in the chambers the ridges are quite deep and defined by the time they have been removed the valve heads are in effect raised within the chamber this unshrouds the valves and allows the valves to breathe instantaneously a good mod and will improve torque.
allan.
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My mate (who I'm postoing on belhalf of really, he hasnt got the interweb.) recently rebuilt a smashed 1990 gti. (see pics)
I got him a 1.8L 16v head off ebay for somthing to rebuild/port/polish over the winter, I was looking at your thread recently but was confused by serial numbers as they dont match up with what we have.
The numbers we got are....
The ebay wonder...
Cast number ---- 027103373E
Year ---- 1988
??? ---- H??
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the one on the car....
Cast number ---- 051103373
Year ---- 1990
On the vin plate ---- 05660616V
Cam belt cover ---- KR0449 857
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======================
Any ideas as to wich is the better flowing head? (I'm assuming the later one...?) or if either has better cams??
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EDIT ; ooops x repost!
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also, what wheels are those? are they quite sought after?
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also, what wheels are those? are they quite sought after?
Wheels are VW Estorils look great when polished. Took me a year to find a good set for my Monza Blue. I see from the head rest shadow on the N/S he also has Recaro seats.
Those numbers on the head casting (*** 103 373) are for a complete head and not a bare head casting which ends *** 103 351. The 027 is the early 1.8 16v unit with better intake ports. The later 051 heads were a bit more restrictive on the intake ports but had better exhaust ports where also on the 6A and 9A motors but with tamer mid range intake cams. If both came off a KR motor then they would carry the better intake cam as the exhaust cam was the same on KR,PL,9A and early 6A codes. See the list above to get the cam part number for the KR intake camshaft. I also state that VW still mangaged 139BHP from both head castings so the performance may be down to the intake cam.
A:
whats the intake valve seat size for a kr?