pontiac 400 valve adjustment

The lock nut is torqued to the bottle neck of the stud or the end of the threads. cam or no cam. Come join the discussion about performance, modifications, troubleshooting, maintenance, history, and more! cole. https://www.google.com/search?q=intAgAEEs&biw=1089&bih=527#imgrc=h4aATxujEZIM-M: 1964-1974 Tempest, Lemans & GTO General Discussion, 1964-1974 Tempest/LeMans/GTO Tech/Electric Wiring, Service, Maintenance and Technical Discussion, 1964-1974 Tempest/LeMans/GTO Restoration Projects, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. That way I can check to see if the push rods spin or not (no preload) if they spin I usually tighten them just enough to stop them from spinning. I'd loosen them up until they rattle while idling, then tighten them down until the quit and go 1/2 a turn past that point let the engine idle for 30 seconds before tightening the poly locs. Pontiac offered 3 different lengths of push rod, each .060 inch different, to compensate for valve grind, block/head surfacing, other issues like valve train variation when the engine was built at the factory. just make sure of your plunger travel. uh i hope someone can clear this up cause i just spent 2 hours adjusting them this afternoon. The motor is a 400 4bbl with 6x heads. This car and engine seems all stock and won't be run hard. Powered by vBulletin Version 4.2.3 Copyright 2022 vBulletin Solutions, Inc. All rights reserved. right?? Tomorrow I will torque each nut to 20 ft lbs with the individual valve closed. Turn the crank till the lifter is down, tighten the rocker till you take up the slack on the push rod, then give it 1 1/2 turns to preload the lifter??? When I installed the heads before I went by the cam install instructions. A photo of this is attached. That Vac guage reading is classic Valve adjustment too tight. This was when I was young and broke just trying to add some HP to a mid 70's daily driver with the smallest possible $$$ outlay. I recently removed the heads off my Pontiac 400 block and was wondering about the valve adjustment. Pontiac-Oakland Club International Forums. Well I'll let ya's know by the end of the week how it runs. Thanks Greg that is the same way I adjusted them before. The stock Pontiac nut bottoms out on the bottleneck portion of the rocker stud so you cant move it past that point. it goes E-I-I-E-E-I-I-E,i also am running performer,ARP7/16 straight studs,Mr Gasket poly lock with set screw. Secondly the driver's side has a sheet metal shield above the rockers below the valve covers. I'm not asking for much. thats what im running the performer(cause i had one laying around) the XE262H with new lifters and push rods i changed to a 7/16 stud with comps roller tip rockers. The "performance" Pontiac heads have screw in studs and guide plates from the factory, the only down side is the 7/16" to 3/8" bottle neck stud. The other, and later method is the valve covers will have "oil drippers" spot welded to the tops and serve the same purpose. Even if you have roller tip rockers? You are missing one or someone left it off. We need to know if you have a stock cam or did you go bigger with and adjustable valve train (which you must do with a bigger cam). BTDC.) For a better experience, please enable JavaScript in your browser before proceeding. They will look like little fingers protruding from the top of the valve cover. It may not display this or other websites correctly. It sounds like you've got a couple valves too tight. Patient: 1967 GTO Convertible with 400ci, hydraulic flat tappet lifters (assuming this because car is stock) & TH400. the correct way to adjust rockers on aftermarket cams is to have the lobe on the flat spot of the cam, which is done one of 2 ways. 0 Members and 1 Guest are viewing this topic. I am disappointed that I cannot fine tune the valves. Thirdly, I purchased new cork gaskets. Not sure I'm clear on that with regard to a Pontiac, would work for a Chevy. A forum community dedicated to hot rod owners and enthusiasts. You need to use a positive locking nut (poly-locks), because the stock type nuts won't hold the adjustment. i was hoping you would chime in to since i built mine to match yours. Thanks mike, i let the machine shop talk me into the poly locks. The motor has a crane cam in it with hydraulic lifters. JavaScript is disabled. A. It is owned by a friend of mine and I'm doing some work for him. Only to install a freshly done set of 670 heads and a new style rear main. :thumbup: If any of the valve train components have been changed, such as the cam, you can't use the stock adjusment method. What is my method of installation? You know I'll do it that way again and I'll only give them a half turn. If you must keep it running here, please support this endeavor and select a support plan - which starts at only $0.16 cents per day. Is there a torque spec for these rocker arm nuts? Thank you to both of you. did you buy a new cam?don't put new lifters on an old cam or you'll scap the cam,also the only gain switching to the performer is weight savings,everybody says XE262H is one of the best cam out there right now,im running the old school 268H,(pulls REAL hard till 4500RPM and then runs out of steam) it was in the engine when i got it the car,it doesn't require adjustable vavle train but this year i switched to full adjustable with roller tip rockers.i used the method in the link posted by Clint s worked perfectly.good luck! View Full Version : Valve Adjustment 67' 400 with PolyLocks. Some gasket sealant or install dry? Come join the discussion about restoration, builds, performance, modifications, classifieds, troubleshooting, maintenance, and more! The easiest way to do it is with the car running. Please don't miss the point that unless you have some sort of locking/poly-lock rocker nuts, Pontiac factory valve trains (using the bottleneck studs) are *not* adjustable. So I figured if it was a ringseat problem, new rings would resolve it, if it was sucking oil from the worn guides that would resolve it. None on the passenger side. The heads will be ready in a week and when I re-install them I would like to know from the membership on the proper way to set them up. It is a little messy, but works fine, did it many times took a valve cover and cut a strip out of the top to get at the nuts. For a better experience, please enable JavaScript in your browser before proceeding. Is there anyone out there that can help me with my valve lash question. You are using an out of date browser. The stock one is just a torque and go thing and there are several methods of doing the other way. I just need a little help. Thanks. New rings and bearings installed "just because" (I was burning oil bad from a previous low mile 0.030 rebuild) with not doing the 100,000 mile heads. link to a head, CTRL and + will blow it up. I did have a couple of pressed in rocker studs pull out in just a few miles of "spirited driving" It probably would not matter if you used all new parts like I would today, but old habbat. will work. If the aftermarket cam has a different base circle, as they usually do, the plunger in the lifter is either pushed too far, or not far enough. A forum community dedicated to Pontiac GTO owners and enthusiasts. If true then I should just make sure all the nuts are tight with the valve closed and reinstall the valve covers with fresh gaskets. JavaScript is disabled. The Fora platform includes forum software by XenForo, VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Is this correct? Loosen up until it starts clattering tighten till it stops and then 1/2 turn and lock it down. Last fall I tore down my Pontiac 400 "WT" motor from my 67 Firebird. In either case, the set up is not correct! On a cold engine, just torque it to 20 ft/lbs Valve position doesn't matter. The 1964-1974 Pontiac Tempest, Lemans & GTO, 1964-1974 Tempest/LeMans/GTO Engine Tuning, The Fora platform includes forum software by XenForo, www.pontiacstreetperformance.com/psp/rockers.html. This assumes stock rocker arms and stock bottle neck rocker arm studs. They say it does not matter if the valves are open or not, but I always torque them with the valves closed. Im so used to screw in studs, i had forgotten about pressed in, had that happen on a 69 small block Chevy. That is it, from front to back 1,3,5 and 7 are on the driver's side 2,4,6 and 8 are on the passenger side in that order. He takes care of it and does not drive aggressively. Would it be the same as a sb chevy. For a better experience, please enable JavaScript in your browser before proceeding. I would swap the cam & lifters and reuse all the other parts. I hate poly locs, they're a PITA to keep the setting right while locking them down, IMO. The shields are "oil drippers" which capture the oil splashed by the rocker arms and directs it to "drip" back into the rocker arm to aid in lubricating the rocker arm ball. To me this is the easiest way and these Pontiacs a a bit finicky when it comes to valve adjustment. here's the procedure per chilton & clymer manuals. If you've got high pressure springs in the engine then yes moly push rods are cheap insurance. vac gauge jumps about 4-6psi (cant remember the number, ill check again and write it down. last night i reset the dwell and timing (30 and 6degr. as long as the valve length is at the right height, assuming all else is good, the stock valve adj. IF any of the things listed have been done, different length push rods will be needed. 50 dollars worth of polylocks save you alot of heart ache down the road. JavaScript is disabled. I cant get the car to idle down to the recomended 500RPM in my book. I think i have a vac leak. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register. I thought the XE262H cam doesn't require an adjustable valve train? I'll check for the oil groove and the contact point of the rocker on the valve. If you try to use any of these procedures with the factory rocker nuts, they -will- come loose and you won't be happy with "what happens next". i really appreciate that link it will help me out alot when i do this tomorrow, but i have one question which valve is exaust and which is intake? If this is a stock pontiac head, the proper way to adjust the vales is to torque the nuts to 20 ft. pounds. I think I gave them a full turn and a half before. Ebay typically has these. Starting with #1 cylinder, turn the engine over until the exhaust pushrod just begins to move up. Any suggestions? The standard "set distance" valve train is a real issue. Please consider whitelisting my site in your ad blocker. In the coming weeks I would like to change my intake as well as my lifters and would like to know if there is a simple resource (manual, web site or tip)as to how I can adjust valve lash. I understand what you are saying, but I have found a couple of times when reusing used rocker parts that they did not quite work well together. But the difference is the 1/2 turn part. Thank you. http://www.pontiacstreetperformance.com/psp/rockers.html, Quote from: Clint s on July 20, 2009, 07:40:42 PM, http://www.78ta.com/gallery2/main.php/v/soonerta/, Quote from: SoonerTA on July 21, 2009, 09:24:15 PM.

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