-
1.6D vs. 1.6TD crankshafts
by
oblique
on 27 Dec, 2022 18:53
-
Is there any difference? I know the NA blocks did not have the oil squirters for piston cooling and the intake valves in the head *may* be different between the 2 but the cranks, rods and pistons are the same?
Found a clean NA 1.6 motor at the yard and want to know if i would be able to use it as spare (or build) on my TD.
2 pics each of 1 main journal and 1 rod journal:
-
#1
by
Dakotakid
on 27 Dec, 2022 20:23
-
The very earliest td cranks had heat-treated snouts which I believe was more for running air conditioning than any other reason. I believe they quit this practice. These crankshafts have very hard bearing journals....at least the German ones. I tended to see more wear-ridging on the Brazilian cranks and I actually threw the Braz's away.
On the 1.6 and ALH engines I have rebuilt, I always hand sand the journals down to 3,000 grit and my stuff runs like the wind. I am sure others will take a dump on this suggestion.....but, the way my stuff runs, it is hard to dispute the practice. My bearings are well-oiled.
If turbocharging the n/a blocks is a crime....then, I am a BIG sinner!
Actually, in all the years I have run 1.6 engines....I have NEVER roached a crank. Follow the intelligent coaching found in the Robert Bentley manuals and ignore the billyjoebobs out there. Always use assembly lube when putting an engine together and do NOT apply hardly any oil to the rings when you slide them down the cylinder. Place your top ring gap 180 degrees away from the exhaust valve....the 2nd ring 180 off THAT first ring and place your oil gap away from the #2 gap and NOT above the wrist pin. BE VERY fussy with assembly. It all pays off. Do not wear your ball cap tilted and rotated 45 degrees from front either.
-
#2
by
oblique
on 28 Dec, 2022 00:05
-
What about overboosting NA blocks? I have a Giles pump and it will be running 15psi for sure...would the extra cooling oil would be good for longevity?
I know VW made mark2's in Brazil
Africa and China well into the 2000's but I assumed all mark2 diesels (up to '92 produktion) came from Germany. All VINs Ive seen back that up but obviously I dont know for sure. I can check the crank itself.
As for the blocks, they all seem to get the ring wear in the bore and leave a nice lip at the top, between deck and top of piston stroke...it seems to be more pronounced on boosted motors? Anyway I assume the bores should be enlarged when starting fresh..obviously the ring end gap is slightly bigger but also the rings dont sit as deeply inside the piston grooves...i assume this is a good pathway to loose some compression/blowby.
-
#3
by
ORCoaster
on 28 Dec, 2022 22:49
-
Do not wear your ball cap tilted and rotated 45 degrees from front either.
Awh come on dad ALL the Cool kids wear em like that.
-
#4
by
unitedracing
on 30 Dec, 2022 08:08
-
What about overboosting NA blocks? I have a Giles pump and it will be running 15psi for sure...would the extra cooling oil would be good for longevity?
I know VW made mark2's in Brazil
Africa and China well into the 2000's but I assumed all mark2 diesels (up to '92 produktion) came from Germany. All VINs Ive seen back that up but obviously I dont know for sure. I can check the crank itself.
As for the blocks, they all seem to get the ring wear in the bore and leave a nice lip at the top, between deck and top of piston stroke...it seems to be more pronounced on boosted motors? Anyway I assume the bores should be enlarged when starting fresh..obviously the ring end gap is slightly bigger but also the rings dont sit as deeply inside the piston grooves...i assume this is a good pathway to loose some compression/blowby.
What I did with my Vanagon was to have the pistons ceramic coated. This was recommended by a couple engine builders I spoke with. They said forget adding the squirters and just get the coating. It was fairly inexpensive also. Apparently some oems are doing this now instead of spray cooling
-
#5
by
oblique
on 31 Dec, 2022 05:54
-
Interesting. Is this really the only difference? The NA block im looking at has a large "1.6D" cast into the back...are TD blocks the same? How different are the oil passges between the two? If they are different castings, maybe the TD also could be thicker or more gusseted, etc.?
-
#6
by
fatmobile
on 01 Jan, 2023 05:17
-
I had a TD block crack near one of the mains.
I've never had that happen to an NA block.
I know that doesn't mean much, because of the low sample numbers.
I have beat on some NA engines though.
Even the old 1.5s, and the block and crank were not what failed.
-
#7
by
oblique
on 01 Jan, 2023 05:47
-
Wow so sustained 15psi on the NA block should be fine? 😁
These are the only numbers i could see on the crank...looks like partial part numbers? Not sure how this is read.
-
#8
by
fatmobile
on 01 Jan, 2023 16:28
-
Yeah I've done that and had no problem.
Even a little more.
It's a safe maximum for a 1.6D.
EGTs are more important than boost.
Keep it under 1200F.
I've spiked over 30psi with the uncontrolled VNT,.. using head studs.
Ran it at 22psi and 1200F for a sustained time,.. before I found the VNT max efficiency is around 15psi.
Flying down the interstate it sits at about 8 or 10psi with the VNT-15.
So hard to imagine 15psi sustained without a nice hill.
-
#9
by
oblique
on 02 Jan, 2023 21:07
-
-
#10
by
fatmobile
on 03 Jan, 2023 18:32
-
If you loosen the cam caps and remove the lifters you can put the cam back in place and see if it rocks/ teeter-totters.
That will tell if the head is warped and how much.
I was fortunate enough to have a bunch of prechambers from old heads I scrapped.
So I don't know where to find new ones.
Looks like a hydraulic block so check the cam for chips where the valves ride.
-
#11
by
oblique
on 05 Jan, 2023 16:45
-
In terms of the head warping...do they always dish away from the cam on the ends? Otherwise the teeter-totter method cant tell you if the head is curled upwards.
I have 2 junk heads I can pull parts from..reading about precups it seems:
1. They are supposed to protrude a few thou past the deck...i assume this is because aluminum expands more than the hardened steel they are made from and the head surface is flat at temperature?
2. They are not supposed to be a tight fit cold. A light interface is ideal, again, i assume because aluminum expands more than steel.
3. You can knock them out though the injector holes and peen the head slightly if they are too loose.
I have a couple junk heads i can pull the precups from as well.
A note on valves: where do they typically wear? I assume at the guide..what about at the seat or otherwise? Retainer? Pulled one each from a cyilnder...intake has a part number but the exhaust doesn't...I have heard this might be typical of OE?
-
#12
by
fatmobile
on 05 Jan, 2023 21:17
-
From my experience they are always high in the center when they warp.
So the cam teeter totters.
I think prechambers protrude because they are held in by the head gasket and this allows more force on them.
It's a pretty tight fit, You'll find that out when you try to remove one.
I put a valve adjuster shim on them and smack them good before I try to remove them.
When removing them I fill the prechamber with salt so the pressure doesn't just hit one spot.
It spreads out the impact. Otherwise you can crack the prechamber right near the exit hole.
All prechambers are not created equal in size.
The prechambers from a 1.5D will fit a 1.6TD head but an NA prechamber won't.
I see most of the valve wear on the part that contacts the seats.
-
#13
by
oblique
on 06 Jan, 2023 18:58
-
Alright, in terms of the head:
1. Bentley says cam caps are not interchangeable in terms of positions...are they all different? I think folks swap camshafts all the time, no? What about the lifters? Bentley says same, don't move them around...but we do anyway?
2. Bently has nothing about cam lobe spec...just info for journal wear and shaft runout...what is a good way to tell if a cam is still good? Whats the difference between a 'just good enough' cam vs. like new?
3. How do I remove valve guides and seats from a junk head? replacements are very difficult to find, as far as I can tell.
Thanks for precup removal tips, I will try popping them out tonight.
On an unrelated note, was at a wrecker today and saw this at the vac pump..am I crazy or does that look stripped out in one direction.
I was after the intermediate shaft but couldnt pull it out - it was binding even w vac pump removed - is it catching on rods or a counterweight on the crank at this position in its rotation? Head has been off for a while, bores are pretty rusty.
Also: can the intermediate shaft bearing be replaced and int. shaft ground down? I do not see the bushing as a separate part, wondering if there are aftermarket options?
Thank you for all awesome info thus far.
-
#14
by
fatmobile
on 06 Jan, 2023 22:03
-
Yes, cam caps are different. All different? No.
Occasionally you can find a matching cam cap from another head.
The lifter kind of wear to the bore and shouldn't be swapped to another hole.
Cam wear can usually be seen at the peak, where it has the most force against the lifter.
I think valve guides can just be hammered out. I think a shop would use a press. Hot head cold guide to put them in.
I think, from what I see in the pictures, the oil pump shaft and vacuum pump are too far gone.
Looks like they have started to "ramp" which shoves them away from each other.
I-shaft should pull right out even with the vacuum pump in place.
Turn and pull.
Don't grind the shaft down. Sometimes they need to ream the bearings after install.
I like sealed power I-shaft bearings. Others are too loose or tight.
You want it to turn a little hard by hand after new bearings and I-shaft are installed.
