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Engine Specific Info and Questions => IDI Engine => Topic started by: NintendoKD on February 12, 2010, 11:50:40 pm
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Ok, I have heard this beat up one side and down the other, I want the scoop. Do the Mechanical lifters allow for more head power? How does this happen, quantifyable? Setup? I want to use mech lifters with the aaz setup like another member here has done, but don't want to do so until I'm sure that the investmnt will be worth it, or if it will be worth it to be different. ;)
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No difference, not worth imho. Unless if you go crazy with camshaft, and I doubt it very much.
Conversion lifters are available at Rosten Performance for example, 17€ each.
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I don't have a dino or anything to measure, but all the mechanical engines I have ever had all reved noticably better than my hydro engines. Don't know if they make more power, don't know if they are more realiable. All I know is that all of my mech engines were more fun for the style I drive. Probably isn't measurable or effect HP overall. To me it just seemed like the engine came to life sooner than my hydro engine.
At the price MJF just quoted with all the work involved I wouldn't do it though.
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mech lifters do make more power and rev better, but the real gains with mechanical lifters are at much higher rpms than our engines will ever see
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mech lifters do make more power and rev better, but the real gains with mechanical lifters are at much higher rpms than our engines will ever see
maybe your engine ;), mine will have a knifedged crank, girdle, dry sump, and "eventually" a beefed up giles pump, I can only guess, but I suppose that the rpm range will certainly change, especially the response in the low ent and the height of the power curve giving more of a top end, If only the crank were de stroked and could have a decent static compression ratio "starting would be impossible :'(" One of my goals is to stretch the limits of the engine and it's capabilities to the limits, if anyone can squeeze more power from mech lifters it will be me. How will this work? can anyone actually tell me? I am much more farmilliar with Hydro engines is this because of the reduction in vibrations in the valve springs at high rpm's? *SYLAR* tell me how it works
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two motors, with everything else the same, the mech will make more power, especially at higher RPM's
it comes from the fact that hydro lifters require more oil, which takes more power to pump.
also hydro lifters "squish" every time the cam presses on them, and take time to pump back up.
at higher RPM it is possible for the lifters to squish faster than they can pump back up, causing the cam to loose contact with the lifter(like poorly adjusted mech lifters) and also loose valve lift, which affects how much air gets to the motor.
as others have said, this pumping problem of hydro lifters occurs most often at much higher RPM than our motors see.
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good, mech lifters for my aaz it is, one question down, about a zillion more to go ;D
thanks guys,
Kevin
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I think we'll all be interested in hearing back from you on the total costs associated with this conversion... I would have thought this is an extremely expensive way to gain a half-horsepower, but happy to learn how it plays out for you.
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why could one not simply leave the valves and springs alone, and install mechanical lifters with lash caps under them to make up the difference in height?
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there are already mech lifters for this application and no modification is necessary, just use the shims to get the correct clearance.
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hey kev, have you ever built an engine before? how many?
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hey kev, have you ever built an engine before? how many?
;D
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In theory, in my minds eye, yes, a thousand times over, in real life...... *small voice under his breath* no :-[ I have installed engines, taken countless apart, and studied the operation thereof extensively, but as i hvae said this is truly my first build.
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i thought mechanical lifters do not simply just go into a hydro head
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sending off both heads to a rebuilder in norcal, guy says he can do it, as well as swapping the 7mm valves to 8mm.
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The mechanical lifters do not go into hydro heads (answering the above question)...at least the stock ones do not.
However, there is an aftermarket manufacturer who makes mech. lifters which fit the hydro bores nowdays. One of these guys can tell you where they are sold. I'm really thinking of going that route soon.
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That is what I am going to do, just wanted to make sure they are worth my while, and the money spent getting them into the head. ;D I'm no idiot, I knew that they wouldn't just slide right in and work *dur dur DUR!*
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this is from saukraut's thread, the link for mech lifters for hydro heads is here:
http://www.crespocams.com/servlet/Categories?category=Cam+Lifters%3AMechanic (http://www.crespocams.com/servlet/Categories?category=Cam+Lifters%3AMechanic)
under the detailed information tab in the item description it says: and I quote
PART NUMBER: ML-VW8v35 MECHANIC FOLLOWER CONVERTION SET
Manufacturer: CrespoCams
For Engine Codes: ALL Audi, Vw & Ford 8v with Hydro Lifters
Do i have to machine the head?: NO
Is a direct replacement part?: YES
Can i use stock valve springs?: YES
Are Top Shims Included?: NO
Which widths of shims are offered?: From 2.75mm to 4.80mm in 0.05mm steps.
Which is the diameter of the shims?: 31mm (1.220")
Follower Outside Diameter: 34.96mm (1.376")
Follower Height: 25.90 (1.020")
Follower Weight : 59 grams
MSRP: $125.95 + S&H
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You will need mech camshaft too, profiles are different.
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This is on an aaz? saurkraut did this, I do not remember him saying anything about a different camshaft, I'll check again. I wanna keep my aaz camshaft, I don't wanna do anything else with the head*temper tantrum* >:( ::)
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are hydro lifters a different diameter than mech ones?
I know the stack height is different, but why could you not put lash caps in to make up the difference?
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I just sent a message to saurkraut, he's currently not online, but I hope to recieve an answer fom him soon on just thes types of questions. Hold still and don't move or I might cut off your ear JK. ;D The way it reads in his thread all of his modification was for naught because of the mech lifters that are made for just this application. In other words no head modification machining or what have you....... I think time, and saurkraut himself, will tell.
thanks guys,
Kevin
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Lifters are same diameter, but there is ~10mm difference in height. So no for lash caps. You can use hydr cam, but it will be loud.
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It's a diesel..... just how quiet is it suposed to be? ;D
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ok, seriously now, is there a mech cam for the aaz? or a way to do it without my engine blowing up? ::)
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why no to the lash caps?
if there is a 10mm difference in height, why not make 10mm thick lash caps to make up the difference?
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yeah, what he said 8)
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ok, seriously now, is there a mech cam for the aaz?
VW abandoned mechanical lifters long before the AAZ engine was made... so at least for North America I'd be pretty sure the answer is "no". Can't speak to engines that may have been available in Europe, and perhaps there's an industrial version of the AAZ out there with mechanical lifters.
Completely unsolicited opinion: it's absolutely your engine and your build... but it seems to me there's an awful lot of angst and expense around grabbing what's likely to be 1/2 a hp or so..(you're going to need to invest in a shim kit and two special tools to go along with your mechanical lifters) and you're committing to increased maintenance (one of the main reasons most manufacturers moved to hydraulic lifters). A different way to look at it: that same cash might get you an upgraded intercooler, bigger exhaust, bigger turbo, or a large part of the way towards a Giles pump... something with much more substantial hp gains associated with it.
As I said, completely unsolicited opinion... and worth exactly what you paid for it!!!!! ;) :D
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thanks vince 8)
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ok, seriously now, is there a mech cam for the aaz?
1,5, 1,6 or custom cam.
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are the lobes the same? the object here is performance. isn't the aaz cam the best available as far as lift etc.? anyone know a custom cam grinder? ;D
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http://www.oregoncamshaft.com/ (http://www.oregoncamshaft.com/)
IDK if they do custom grinds but I've delt with the guy and he was super nice, answered the phone and answered all my questions after hours!!! :o It appeared to me that he really likes what he does :D.
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are the lobes the same? the object here is performance. isn't the aaz cam the best available as far as lift etc.? anyone know a custom cam grinder? ;D
the 1.6 cam is better than the AAZ cam.
and solid lifters require some modifications to make them work right. valves for hydro lifters are shorter.
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If you use the Crespo solid lifters for Hydro heads, no other modification is necessary.
You do have to use the solid lifer lash shims, and have a good assortment when you do it, as the Crespo lifters have a wide variance on required shims.
Find a mechanical 1.6 cam. Hydro cams don't work good with solid lifters.
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ive heard that people like putting the shims under the buckets too on that kinda setup. so they dont fly out when you rev the crap out of the engine.
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ive heard that people like putting the shims under the buckets too on that kinda setup. so they dont fly out when you rev the crap out of the engine.
now that sounds like fun, the kind of fun I want to be a part of ;)
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ive heard that people like putting the shims under the buckets too on that kinda setup. so they dont fly out when you rev the crap out of the engine.
now that sounds like fun, the kind of fun I want to be a part of ;)
actually, i was referring to missing a shift. theres no way these engines can spin 9000 on their own. going from fifth to second is a good way to over rev your engine and have all the pucks fly out of the buckets.
the bad thing about pucks under the buckets, you have to take the cam out to adjust the valves.
ive turned my engine over 7500 before, and all is well.
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very rarely will a shim come out due to too many RPM, they usually come out because of a really big cam, catching the edge of the shim with the lobe.
the general fix for that is either to bore out and install wider lifters and shims, or like you said, install flat topped lifters with lash caps under them to adjust.
-Owen
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very rarely will a shim come out due to too many RPM, they usually come out because of a really big cam, catching the edge of the shim with the lobe.
the general fix for that is either to bore out and install wider lifters and shims, or like you said, install flat topped lifters with lash caps under them to adjust.
-Owen
im not saying this is going to happen to everyone, but it has happened.
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good advice, and also great to know ;D