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Blaubus
Samba Member
Joined: October 25, 2003
Posts: 5153
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 Posted: Wed Oct 26, 2005 8:52 am Post subject: T4 cam replacement- is it really necessary? |
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| my 1700 is being rebuilt right now and i am wondering- is the stock VW cam really as shitty as Jake Raby sez? it isnt that i am trying to be cheap, but instead, i am really wary about the issue of cams going flat these days. Jakes reputation is hard to question, but i have a hard time imagining that VW "made a mistake". when vw makes mistakes, it is what they were too cheap to add, but what they do give is right, in my experience. they certainly didnt make a mistake with the type 1 cam, so how could they have been so far off with the type 4? i feel i need an explanation. |
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Amskeptic
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Joined: October 18, 2002
Posts: 8568
Location: All Across The Country
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| Posted: Wed Oct 26, 2005 9:22 am Post subject: |
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I think Jake has the battle-weary perspective of seeing thrashed engines come in his shop with seriously worn oem camshafts due to serious neglect, and he sees the overheated heads day after day, and how can he but conclude that these engines have lousy heat-provoking cam profiles and lousy cooling?
He has a doctor-in-a-hospital view of engines (if you were a doctor, you would see only sick people).
I got 200,000 miles from my camshaft with no untoward wear, it was in an engine with clean oil. My heads are original with secure valve seats because they are in an engine that has remained cool. And my engine is an anemic 74 gross hp/63 net stock Type 4. I am of the mind that the oem parts CAN last and CAN run cool, but look at the world out there. . . there are very few engines running anywheres near optimally.
I like the original cams and I have no desire for more performance than what they offer. I keep my engine clean and cool. If you do too, you will not be disappointed with an oem cam. If you have an old one that you are trying to decide to install or not, you must inspect it very carefully for any erosion along the lobes, measure the lifts and compare against each other. If you see any pitting or can *feel* the ridge along that strange swoopy x pattern on the wide lobes, yer out, replace it. Good luck to all of us when it comes to lifters. I hope to find NOS old lifters with an oem cam the next build. If you get a replacement cam, there are options, some have better profiles for more performance, you are open to lifter crap shoot however, and you must select a proper gear for the crankshaft/camshaft mesh, any swapping of gears involves the need for careful work and potential spot-facing of the cam bolts so they will clear the oil pump.
Colin
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Bleyseng
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Joined: July 03, 2005
Posts: 4752
Location: Seattle
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| Posted: Wed Oct 26, 2005 10:13 am Post subject: |
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VW didn't make a mistake, they made the cam to run the exhaust hot so the engine would work in cold climates.
260 degree oil temps are too hot for normal driving which is what the stock VW cams are ground for.
Jakes cam grinding just reduces the oil temps which is a huge improvement over stock and will work fine with FI too.
Jake has worked hard to stock cams with the proper hardness matching the lifters so they do work.
VW had problems in the past with cams going flat on new buses back in the day so I have never trusted their cams. Going with a NOS cam and lifters just because its VW is hard to fathom since a lot of new reseach and effort to improve type 4 cams has been done.
Geoff
_________________
70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles |
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ratwell
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Joined: April 26, 2003
Posts: 8717
Location: Victoria, BC
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| Posted: Wed Oct 26, 2005 11:14 am Post subject: |
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| dansvans wrote: |
| Jakes reputation is hard to question, but i have a hard time imagining that VW "made a mistake" |
Not to belittle the effort and improvements attempted and made but there's no money to be made selling NOS cams so you'll rarely here anything good about them from someone selling you an alternative. This is not a criticism just the nature of sales and business.
The epiphany that is repeated many times over is that the original cam was designed to heat up the engine as quickly as possible for all climates. Also consider how cold it gets in Germany during the year. Using that as a basis, VW built their engines for one purpose than others have others in mind. Because of this, one point of view turns VW/Porsche engineers into dummies even though they developed this engine before 99% of us were even born design mistakes not withstanding so I take the criticisms with a grain of salt and try to figure out what the contending issues are.
| Quote: |
| 260 degree oil temps are too hot for normal driving which is what the stock VW cams are ground for. |
I don't see those temperatures.
| Quote: |
| Going with a NOS cam and lifters just because its VW is hard to fathom since a lot of new reseach and effort to improve type 4 cams has been done. |
The reasoning is that VW probably didn't build 3 million of those camshafts hoping the last one they made would wear out as prematurely as the first one. Isn't the factory often able to use a suitable surface treatment technique that is only affordable on a mass production scale?
Not to diminish anyone's efforts but aren't we in the experimental phase while the mileage racks up on the engines with these aftermarket parts while folks like Colin and others have gone the distance? The "this cam sucks" pulling a worn one from a well cared for 200k mile engine isn't helpful.
I remember not long ago, Jake sent out a bulk notice asking customers to remove the unused improved design lifters from their engines and use some replacements he mailed out. Irrespective of cost and reputation how does this prove that using NOS parts is the wrong choice?
I think there are good arguments to support both choices.
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'76 Doublecab
Read the Baywindow FAQ
Last edited by ratwell on Wed Oct 26, 2005 12:30 pm; edited 1 time in total |
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busman78
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Joined: August 17, 2004
Posts: 4524
Location: Oklahoma City, OK
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| Posted: Wed Oct 26, 2005 11:23 am Post subject: |
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Have installed several CB Performnace solid lifter stock T4 cams now, none have gone flat, no overheating, absolutely smooth running. Also done Web and a few others including VW.
Any cam can go flat (wear out prmaturely), any engine can be hot, put a stock or performance cam in and run the carb/FI lean and you will experience hot. Yes T4 cams do take a bit of care when starting up, but all it takes is a "over hardened" lifter and yor cam will be trashed. |
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Bub
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Joined: June 10, 2004
Posts: 1155
Location: Central Washington
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| Posted: Wed Oct 26, 2005 12:37 pm Post subject: |
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Hmm....here's where I get caught up:
IF you can install a non-stock grind and get MORE power AND lower oil and head temps...umm...why wouldn't you do it?
I've also seen too many T4 engines BURN mostly due to heat resulting from the nature of the cam. Its amazing what ONLY replacing the cam can do for your engine.
Anf if you're super worried about a bad cam, have your old one reground and your lifter surfaced.
I know- regrinding on a smaller circle will change rocker geometry..etc etc..the effect is minimal on a stock'ish engine.
Just my .02..
Bob O |
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VWBusrepairman
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Joined: July 06, 2004
Posts: 4726
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| Posted: Wed Oct 26, 2005 1:45 pm Post subject: |
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My question is why not build the engine yourself? Inspect your cam for excessive wear. Stick it back in it's journal, put the case halves together, and be done with it if it's acceptable. I have the stock cam, though mine is a 2 liter with hydraulic lifters and I've seen no failures at this time.
I do have an excessively worn cam from a 1700, which I believe had been ran dirty for some time.
The Engineers at 'dub are no dummies. If so, we wouldn't still be driving their car. |
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Blaubus
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Joined: October 25, 2003
Posts: 5153
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| Posted: Wed Oct 26, 2005 2:03 pm Post subject: |
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aren't "we" in the experimental phase while the mileage racks up on the engines with these aftermarket parts while folks like Colin and others have gone the distance? The "this cam sucks" pulling a worn one from a well cared for 200k mile engine is more marketing that statistical proof.
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exactly what i was thinking when i asked... i mean, didnt we just get past the type 1 hype about remote oil coolers, finned valve covers, aluminum pulleys and chrome fan shrouds, all of which were proven to be detrimental to the T1 engine when used to replace stock parts?
| Quote: |
| If you have an old one that you are trying to decide to install or not, you must inspect it very carefully for any erosion along the lobes, measure the lifts and compare against each other. If you see any pitting or can *feel* the ridge along that strange swoopy x pattern on the wide lobes, yer out, replace it. Good luck to all of us when it comes to lifters. I hope to find NOS old lifters with an oem cam the next build. |
i just got the engine apart today and found some remarkable things. the crank is standard and measures even fatter than the max dimensional spec in the bentley. the lifters and cam are in extremely good shape. i took it apart based on the crank end play indication of .006". i have a cofap 90mm set that i am not willing to waste on a sketchy build. had i known the crank to be that damn NEW, i might have just rebushed the rods and built from there. the engine came apart cuz the compression was poor after sitting for a day, but was good an hour after running. the air deflectors were missing  either it was rust pits on the cylinder walls from sittng for 10 years, or the rings were baked. |
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busman78
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Joined: August 17, 2004
Posts: 4524
Location: Oklahoma City, OK
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| Posted: Wed Oct 26, 2005 2:16 pm Post subject: |
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| Regrinds pose a new whole new dimension to risk. Yep they will change the rocker geometry. Beyond that, if the grind removes the factory hardening and nothing is done you are toast. The same goes for rebuilt lifters. Since hardening is .003 to .010 +/- it does not take a lot of grinding to wipe that out. |
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Jake Raby
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Joined: August 23, 2003
Posts: 7433
Location: Aircooled Heaven USA
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| Posted: Wed Oct 26, 2005 7:47 pm Post subject: |
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Yes- The stock cam really is that bad.. In more ways than one, not just does it have a funky taper on the lobes, but it also has characteristics that force the engine to run inefficiently and thus run hotter.
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| Not to belittle the effort and improvements attempted and made but there's no money to be made selling NOS cams so you'll rarely here anything good about them from someone selling you an alternative. This is not a criticism just the nature of sales and business. |
Ratwell, I suggest that before you make these drastic generalizations that you at least get your facts straight. The FACT is that IF I sold a stock cam I would PROFIT more than by selling the performance grinds. It pisses me off to no end when anyone thinks we make developments for profit only- JEEZ!
As far as the reasons that I sent out my recall for lifters:
The earliest version of my updated lifter was based on a STOCK OEM LIFTER taht was reground(with an altered crown radius to match my cam tapers), parkerized, cryoed and nitrided. The only issue with these lifters is that they were super heavy - taht was really it. As my development with lifters went on we found new castings and completed new processes to them and those were a whopping 50 grams lighter per lifter. I want to stress that we did not send out the new lifters due to any other reason. I sent out new lifters to everyone (the new lifters retail for 70.00 MORE per set than the ones they replaced and I ATE that cost on over 100 sets of lifters for my customers) to make their engine even better because the newest design was testing even better than the old ones in the spintron tests and oil contamination after 30 hours of run time was drastically reduced when analyzed.
I'm sorry but anyone who has not been directly impacted by removing a stock cam, making NO OTHER CHANGES to the engine and then replacing it with a better designed, more modern camshaft designed for modern speeds and fuels has basically no foundation to make a negative opinion on. I have done this many times, in fact I have swapped camshafts 14 tiimes in the same engine and then redynoed the engine and compatred the results. Driving the vehicle after the cam swap would make you think that you were not even driving the same vehicle. While some purists may like that I don't! I wanna run at freeway speeds and have the ability to get a speeding ticket in my bus without fryng the heads and drinking gas like a pig, making a cam swap is the first key to help unlock that door.
The fact is that yes, the VW designers were NOT dumb. The cam they designed was intended to proviide an engine for a vehicle for the masses, but unfortunately all their testing was done in colder climates than we have in the US and that was fine because most of their sales were in colder climates and they could not offer 10 camshafts for different areas. Their efforts were effective THIRTY FIVE FRIGGIN YEARS AGO+! The simple fact that when displacement and valve sizes and port margins changed over the years, there were no camshaft changes to compensate for the altered CR and other changes tells me that something in that design team wasn't going too swiftly! Anyone that thinks a 1.7 engine with super small valves and increased port velocity needs the same cam as a 2 L engine to perform optimally, well deoesn't deserve the salary of an engineer.
fact is that 30+ years of trial and error by many more guys than just me has given many more camshaft opportunities that are IMHO much more beneficial to the engine.
Not many people can back their opinions on something like this up, but I have dozens of tests and data to prove my point all backed up with the fact that I can TOW a full bodied bug behind my bus (while hauling 3 TIV engines inside the cargo area) and my heads will run cooler, my oil will run cooler and I might even pass your ass if you have a stock cam! (yes I have done it on several occasions and every time its been on a trip through the Appalachian Mountains..
Opinions don't make engines run any better, data does so until you have some its not even a fair argument.
BTW- I don't give a damn what the factory did, or why they did it. IMHO they gavce us a great crankcase and everything else can stand to be updated- Hell what in your life hasn't changed in 20-30 years??? Guess what the same goes for the engine so building tomorrows engine like yesterdays was built is the first step in the wrong direction. The factory didn't have coatings, ceramic lifters, Ion Nitriding, Cryogenics or any of the other modern advancements that can be employed to make your bus drivable like a more modern vehicle with less maintenance and more power at the same time...
To the original poster- If your engine is a bone stock 1700 go ahead and assemble it with a stock cam, your heads don't have the capability of outperforming the camshaft anyway, and I feel the stock cam was designed for the 1.7 based upon the numbers that I have crunched anyway- its just too bad that they never did that work with the 1.8 and 2.0-
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Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell" |
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Bleyseng
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Joined: July 03, 2005
Posts: 4752
Location: Seattle
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| Posted: Wed Oct 26, 2005 7:50 pm Post subject: |
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alot of the new cams are also Parkerized along with being hardened.
http://www.parkerizingkits.com/html/parkerizing_faqs.html
There have been several different VW cam grinds for the type 4 as VW phased out the old and replaced them witha new grind. I think there is about 4 cams IIRC as there used to be this great cam website showing them.
My Westy 76 2.0l with 117k on it does get oil temps upto 260 degrees. Stock and never been apart other than to clean the debris and tin.
My 76 914 2.1L witha stock cam never hits 230 degrees even racing but I still am installing a better cam to reduce oil temps.
VW produced cams to fit all conditions but mostly so the cars would run in cold climates. I always figure there is a better way to build a better mousetrap. Just because VW did doesn't make it the best! Thats just how they did it 30 years ago. If I could afford it I would also install Nikasil cylinders even though VW didn't ever make them.
_________________
70 Ghia Black convert-9/69 build date-stock w/133k 1600 SP-barn find now with a rebuilt tranny and engine
77 Westy 2.0L w/Ljet, Camper Special engine-95hp and with LSD!(sold)
76 Porsche 914 2.1L L20c, 120hp Djet (sold)
87 Syncro Westy Titan Red 2.1L 2 knob 100k miles |
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Jake Raby
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Joined: August 23, 2003
Posts: 7433
Location: Aircooled Heaven USA
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| Posted: Wed Oct 26, 2005 8:06 pm Post subject: |
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Geoff, The cams were basically changed for different trannys (std Vs Auto) and the 914 and 412 engines. Two camshafts were used in all 1.7-2.0L engines only, if more were used I have never seen one. The difference between the two is only the lobe centers and those were only used (or I have only found them) in the AW 1800cc engines...
Now one would think that adding 300cc of displacement would dictate more than that!
Thats what my cam doctor tells me anyway!
As Edison said:
"There is always a better way, find it...."
Its not found by having a closed mind and thinking some dude in a white lab coat 35+ years ago was a god!
The stock cam helped the engine warm up faster- Unless you live in Alaska here in the US you won't be needing to worry about that.. Hell look into the future- with global warming we'll all be in the carribbean soon so set your engine up for it today! 
My 9550 and 9010 cams work so well that some customers have bought a dozen! One engine shop used one and has now bought 10 more, I can't keep them in stock and thats because they work and work very well. If they didn't I'm sure you guys would have heard about it broadcast right here- think about that.
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Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell" |
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Blaubus
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Joined: October 25, 2003
Posts: 5153
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| Posted: Thu Oct 27, 2005 6:44 am Post subject: |
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| Quote: |
| To the original poster- If your engine is a bone stock 1700 go ahead and assemble it with a stock cam, your heads don't have the capability of outperforming the camshaft anyway, and I feel the stock cam was designed for the 1.7 based upon the numbers that I have crunched anyway- its just too bad that they never did that work with the 1.8 and 2.0- |
well Jake- this is why i posed the question. but i have heard EVERYONE say the 1.7 is a dog, and i am hoping you arent recommending i use the stock cam just cuz you think its USELESS no matter WHAT i do! after all that you just said , i would think it would run cooler if i had a new Webcam- and i was willing to buy one without even posting this thread- except for all the trouble that cams have with going flat- RISKY! . and from what i understand , it is the lifter causing all these problems? ceramics are what i might have to choose @ 400/set to have no risk... RIGHT?
Again, i have an exceptional crank, rods and case, and the obsolete cofap 90mm set. this engine is not being put together with an attitude that it is expendable! it has hard work to do carrying weight as my contractor vehicle. although i do live in the NE, if i sell this beautifully painted bus to someone in a warmer climate , i will not want this bus to be wasted! and for those who dont know, we get 100 degrees in the summer and there are mountains all over the place. overheating is a risk! by comparison- the CA bay area weather would treat the engine MUCH better in the summer.
Jake could you tell me also... i am going to purchase the galley plug kit from you. do you include instructions with that which would indicate a SAFE torque spec that will not crack the case as i tighten the plugs? if not, could you tell me here? and also any other tips for doing this. it will be done on machine using an NPT reamer and a Greenfield tap. |
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Jake Raby
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Joined: August 23, 2003
Posts: 7433
Location: Aircooled Heaven USA
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| Posted: Thu Oct 27, 2005 9:42 am Post subject: |
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The 1,7 is not a dog. Properly tuned they perform great with the gears from the 002 trans.
What I was saying is the fact that the cam you have STOCK IS SUFFICIENT for the amount of air the stock 1.7 head can flow with stock valves and ports. With the 1.7 you don't have the added displacement to take advantage of any other cam and due to lack of engine size it would be very easy to ad the cam and LOSE performance due primarily to a loss of intake velocity.
I naver attempted to go with a bigger cam in the 1.7 this is due to the fact that the stock 1.7 efficiency numbers lok very good on paper and also the fact that developing 1.7 engine combos was rather worthless.
As for cams going flat:
It took almost 16 months for me to figure out the incompatibility issues with TIV cams and lifters. The end result was the fact that both the cams and the lifters had to be redesigned slightly to promote the surface speed of the lifter and to reduce wear. Through that amount of time I wasted 25 cams (some were reground 8-10 times too) and untold lifters and about 18,000 bucks of test parts and fuel for my spintron device. Here is a pic of the cam/lifter test device
When all was said and done the lifters have been working excedllent. The accelerated wear has gone away and we now see wear less than we ever have, even with dual valve springs with insane tensions over the nose.
While these are working great, the only killer is your luck.. I test lifters constantly and I always test a couple of sets from every batch we have treated to ensure the procedures are still working and need no alterations. Fact is that with bad luck and conventional lifters you are destined for a problem.
The ONLY 100% way toensure that you have no issues is to run ceramic lifters and now the price is a whopping 600 bucks IF YOU CAN FIND THEM. All my engines receive them as a standard because I know the benefits first hand and I can't afford for a cam/lifter issue to occur- it cost m 4,000 bucks everytime it happens in lost time, parts and schedule impacts.
As for the galley plug kit, there are no instructions in the box but call me when you get the parts and I'll walk you through it- hows that?
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Jake Raby
Raby Engine Development
www.rabyenginedevelopment.com
"I've never given anyone Hell, I just told them the truth and they thought it was Hell" |
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Blaubus
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Joined: October 25, 2003
Posts: 5153
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| Posted: Thu Oct 27, 2005 3:47 pm Post subject: |
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| good news for me that the 1700 cam is sufficient. and which number should i call? if memory serves me, there are two? |
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