timdog Posted February 11, 2003 Report Share Posted February 11, 2003 Does anyone know the specs and pitfalls to doing hydraulic to mechanical rocker conversion on a 1987 Quest? I've got the mechanical rockers already, but I don't know what the intake and exhaust back lash should be set at. I left the stock 87 cam in it too. Please provide some insight. Thanks, Tim Link to comment Share on other sites More sharing options...
chiplee Posted February 11, 2003 Report Share Posted February 11, 2003 I don't think you'll have any trouble with the stock cam. Lash adjustment is usually .008 in intake and .010 exhaust, but I've heard anywhere from that to as low as .006 for both. I consider it an upgrade. You can expect an ever so slightly more responsive engine but the real benefit is simply that you eliminate the hydraulic noise makers. They only real con is that you add a required periodic maintainance item. Valve lash adjustments. But I think we should all be pulling the valve cover to look at the cam races and lobes ever other oil change or so anyway so that could almost be considered a pro. Link to comment Share on other sites More sharing options...
Adi Posted February 11, 2003 Report Share Posted February 11, 2003 I did the conversion. Using a stock cam... I love it. I can tell differences a lot of places. And mine need adjusting allready from seating in the head. My car was quite a bit more responsive on bottom end...1k-2500. adn top end I didn't miss teh valve float chatter at 4500 one bit, I am glad it was gone....Yeah I got a tick at idle....big flippin woohaa...easy fix when I re adjust valves. I like and IMHO don't think you'll be dissapoitned one bit. Just my aussie penny worth though. Jay Link to comment Share on other sites More sharing options...
Tim_C. Posted February 11, 2003 Report Share Posted February 11, 2003 Well, a general rule is you can't use a hyd cam with mech rockers due to the increased lift ramp before the @ .050 location on the lobe. As long as it doesn't eat into the cam, then it will be an increase in performance. Worth a try, especially since these guys have tried it. I know one guy who tried it on a naturally aspirated 7500 RPM 2.6L. It didn't work, and ate into the cam? Link to comment Share on other sites More sharing options...
DJpowerHaus Posted February 28, 2003 Report Share Posted February 28, 2003 Can somebody make a list of everything involved in a conversion? Where to get it and how much would be great too. Link to comment Share on other sites More sharing options...
Quest340 Posted March 21, 2003 Report Share Posted March 21, 2003 Mechanical valve train came on 84-87 caravan and voyagers I believe. I wish for a little more info on this because I would like to do the conversion too. I snagged a complete head from a Caravan. Now I just need to know if the valves are the same. I haven't had a chance to pull both heads down and compare parts. Link to comment Share on other sites More sharing options...
j5 Posted March 28, 2003 Report Share Posted March 28, 2003 The valves are different. like 0.006" I think the valve material is harder also. Link to comment Share on other sites More sharing options...
chiplee Posted March 28, 2003 Report Share Posted March 28, 2003 some of the valves are physically longer but not effectively longer. Â The keeper grooves are all located in exactly the same position relative to the valve face. Â So the only thing that changes is the height of the rocker when adjusted properly, the valve doesn't extend any further into the combustion chamber. Â edit: Â sorry I thought you were talking about mech vs hyd valves in starquests. Â I'll read more carefully next time. Â The above info is true for G54B powered starions and conquests. Â I don't know the first thing about caravans Link to comment Share on other sites More sharing options...
Tim_C. Posted April 2, 2003 Report Share Posted April 2, 2003 The carvan mechanical valves are the same as the hydrauic valves. Only '83 & earlier year 2.6L had the longer valves. Early '84 too. That only affects what type of rocker stud to use. Long stud for the short valves, and short stud for the longer valves. Of course, the retainers are different like Chip says. Link to comment Share on other sites More sharing options...
thegame Posted April 26, 2003 Report Share Posted April 26, 2003 i'm in the process of compleating this mod. the valves are the same in the caravan head even the exhaust valves. should help out the top end pretty good. Link to comment Share on other sites More sharing options...
MikeMeyerhoff Posted April 28, 2003 Report Share Posted April 28, 2003 I'am probably gonna get a "preped" head from mwt with the 284 cam... I have my 88 TSI's orignal hyd rockers and I also have a set of caravan mech. rockers I was planning on using with the new head. If I understand everybody, I should be good to go right with the mechanical setup right?? mm Link to comment Share on other sites More sharing options...
turboTSI Posted April 28, 2003 Report Share Posted April 28, 2003 ok then for me what would be a pro and con.. and what do I need to do this or what not... I will use: 284 cam HD springs SS valves non jet head mechanical rockers anything else I need? or u might recomend turboTSI Link to comment Share on other sites More sharing options...
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