vettemad

I got about 20 miles on my 70 toro since rebuild...what seemed like a vibration problem has plaqued me from the start....I have eliminated all the things you'd think of first like flywheel correct and undamaged, torque converter, changed that, vibration damper 2nd new one there, replaced stock inginition entirely with hei and new spk plugs... so after eliminating these things I am back to considering things I've seen in the past like broken or weak valve springs which was an early thought but did a compression check and found all cyl. 195- 200 so abandoned that line of thought...now I'm back there and did a vacuum test which I should've done in the first place...duh! well that reading is in the normal range at all times but flutters about 4 points at the top....I don't do motors everyday so I've read many online vacuum diagnosis pages which most say this is a reading that reflects bad/broken valve spring....I've got the covers off and no broken ones visible and although I can move them with my hand they seem ok, I also read that after valve job you may need to shim retainers to make up for extra height of valve stems due to valve job....well all my rocker arms seem really tight and I unbolted a couple of retainers when at tdc to find that the valves move a 1/4" or more to close!...whats up with this??? How'd I get decent compresson readings??? The springs are single ones and new, the push rods are new and matched the originals correctly the hyd. lifters are new and double checked for correctness, they fit all kinds of engines tho....the lifters seem stronger than the friggen valve springs...should I go with double springs on stock toro motor, non gt? or shims? I need some real imput here....It actaully idles pretty nice when warmed up but starts the vibes just above idle and goes the rest of the spectrum....in gear or not but the worst around 40 miles per hour in third gear with slight acceleration....I've been screwing with this for weeks now and need to solve vibration or running problem what ever this is....thanks now!...cliff

Warhead

1st off, you are not unbolting retainers (those are the round things that hold the springs, and they are held to the valve with keepers), you are unbolting the rocker bridge.
When this was assembled, it should have engaged the pushrod about .050"-.075" max BEFORE the bridge base was all the way down to the head. Whomever did the valve job needed to SHORTEN the stems with the valve grinder before final assembly. Most shops will have a book-that they have to pay for- that lists the heads, and what height they should maintain.

You may be able to use a single 5/16ths washer (.060" thick is the most I would go) to shim below the rocker bridge, and artificially raise your valve gear. This will definitely tell you if it is the problem, it will most likely run a LOAD better.

Without seeing it in front of me, I am pretty sure that a complete valve job was not done by the tech (?) who assembled them.

Shimming the springs, will only equalize the pressure exerted by the spring, on each valve. You should have a minimum of 85#seat pressure.

I am not sure why you would have so much compression if the valves are not closing, are you sure on this reading? You may be right on the verge of bottoming out the lifters, or past it with some cylinders. Anyway, as oil pressure goes up, it's gonna want to keep the valves off the seats more.

You may want to also contact colormegone on ROP.com (aka Jim), he is in Ill, and he KNOWS Oldsmobile heads.
http://www.jsmachineoldsmobile.com

My thoughts,
Jim

vettemad

Hi Jim, yes, I was using wrong terms...what again? but was trying just that. with .060 washers I found that it fixed some but could make an adjacent valve too loose and this is kind of funky with a one piece 2 place rocker bridge...thats when i decided to post...My builder initially said he did'nt think this was the problem but I could try 0.30... but I have'nt found them that thin in 5/16 ...he did the heads including guides and short block and I assembled the rest which I have done many times....I will say my builder could be a little more helpful...but if it's his fault he don't wanna know i suppose and i'm sure he thinks it's something I've done...possible too but I'm experienced as well, the compression test was as stated... I was reading in my old motors manual that was the bible when I did do more wrenching back in the late 60's and eary 70's before I got into bodywork/rebuilding that the intake valves start opening at 20 degrees before tdc hmmm....anyway I appreciate the imput and want more!...actually i'm 40 miles due west of chicago...is this link for you or color me gone?...thanks, cliff

cutlassefi

If you're checking compression during cranking, weak valve springs probably won't show up. I did a compression test on a 383, had 180-190 during cranking, but ran like crap. Turns out the lifters were adjusted too tight. Once it started the lifters pumped up and held the valves open. I'd check some of what has already been mentioned. Along with that get a pair of plastic pliers and pull one plug wire off at a time to see if it narrows it down to a specific cylinder.

vettemad

hi cutlassefi, I already did the wire off test a while back, but it was at idle when the motor runs best and all was good, Now with the V. covers off It'd make a mess of my otherwise almost spotless motor compartment....but I'll revisit that angle if I can't get it cured...and right, even if the springs are weak they might well hold their own at low r's and oil pressure....but these are new,but just the low perf single spring stockers...I wonder if they're rejects or if double springs would help...If I gotta do the work anyway why not go with the double spring...but I'm gotta try to find 030 spacers first and try that too but keep'em com'in I need all the ideas I can get bounced off me about the whole damn thing and you guys are a real world knowlege base!...Thanks, cliff

compedgemarine

few questions. when you say you unbolted the rocker bridge at ttc was that on compression or exhaust. if exhaust then you are in the point of overlap where the exhaust valve is closing and intake is opening so yes the valve could move 1/4" at that point. when the engine was machined was the block decked? the heads milled? the valve stems cut? when you deal with a motor with out adjustable rockers you have to machine everything together to bring it back in spec as was mentioned by Warhead.

vettemad

here's what I did, pulled covers for spring inspection, tried wiggeling some of the rockers, all seemed overly tight with zero movement...then unbolted bridge on #7 cylinder not at tdc, I saw large movement on closed valve the other was open...then I installed the 060 washers under the rocker bridges on odd side of engine and cranked to motor, I then went back and saw at least 1 closed valves on that side now had too much lash, so then I decided I needed to be at tdc on a cylinder and hand cranked to tdc pulled the distributor cap to see which cylinder was at tdc and it was #6...so yes compression stroke #6 is where we're working and both valves move to close by 1/4" on that cylinder...I'm gonna look again but I think the ends of my valve stems are shinney smooth and not dull from machining...I really need to find some 030 washers and try that....the lifters should self adjust for minor varibles...I'll post later with those results...thanks, cliff

Warhead

Yes, on each individual cylinder.... as the engine spins...you will see the exhaust open/close, then the intake O/C...then you will have a lull before they do it again.
Do the check after the intake closes all the way.
This will get the lobes on the heel of the camshaft.
Once the lifters pump up (?!), you should have a LOT of pressure on the rockers here.
I would not use that as a guide, just the distance you measure from bridge base to head.
Jim

80_cutlass

http://www.summitracing.com/parts/CRN-99179-1/

sb

vettemad

thanks for the link, but I found some at Menards and installed on all rocker bridges...the results? well, slight lifter noise in a few cylinders.....more responsve throttle....vacuum gauge still flutters at top between 21-22 when before it was 3-4 points flutter between 18-21... still has vibration...I also removed plug wires while running at idle and at about 2.5k r's and the motor reacts normally, the vibration remains unchanged throughout that process...one last stupid question before I set fire to this bitch....The flex plate looks perfect no defects and correct, I lined it up with old crank marks when I installed it, I have been told that olds 455's flex plate will only bolt up one way...that is correct right???.... I've already insured it so....thanks guys...cliff

vettemad

just makin sure warhead's gettin this too

Warhead

Yup, I got it.
I had to work today.
Don't burn it. That is a nice car, it is not her fault.
Second, the flexplate only goes on one way, and you can not get all the bolts in if it is from a 425, unless you have a 425 crank in it. The balance weight goes toward the transmission (transaxle).
That said...
Given all else being in good condition (dist, carb, etc)
If you have a more responsive throttle, I would say (while sitting behind this screen-not the best way to diagnose it) you are on the right track.
I will stick my neck out here and say there is probably one that is hanging a bit higher than all the others.
Throw a straight edge across all the retainers to see which one (ones?) are sitting up higher than the rest. That would be the one I would look at to check for excessive height, and blowing off your compression stroke.

Really, the best way is to get someone with longtime experience to get his head under the hood of this gal, and diagnose it thataway. Do you know anyone locally that can help with this?

Jim

vettemad

well Jim, I am long time old school...I grew up making a living wrenching on this era...I'll be 57 this year, this one's just got so many if ands and buts it's a nightmare at the moment(s)...Start'in to remind me of an OBD I car! I've had enough today we''ll see what I can come up with tomorrow....thats if I don't get a bad hangover...Thanks, cliff

vettemad

hey jim, by any chance you got a vacuum diagram that covers a 70 toro? or close? I did wind up with a hangover so I'm mov'in slower than usual but so far have at least got out there and pulled all the vac lines to make sure some external vacuum operated attachment was'nt causing the fluttering vac gauge....I was never sure where the lines went in the first place since it was apart when I got it so I used best guess and would like to have them where they're sposed to go for sure....I'll pull the covers and try the straight edge idea tomorrow, I just gotta find a short one....thanks, cliff

Warhead

Find the TALL one!!!
I will check what I have in service manuals.
Jim

vettemad

Hi Jim, I meant short staight edge....most are yardsticks!...I did get one side done yesterday, they're mostly all even except #1 intake is about 020 lower and another I can't remeber which is about 010 lower....this is rockers removed and straight edge across the top of stems, my old "motors manual" lists a specific measurement for valve height after valve job but thats using special (gm?) tool that looks to brige head at valve cover edges then you're supposed to measure off that to stems...hmmm...after the lastest round of storms wrap up I'll get out there and see what the other side looks like....don't forget the vacuum diagram if you can get it....thanks, cliff

vettemad

Ok jim, I got done using straght edge and found one or two on even side @010 under the rest....I got to thinking since I did'nt write down the first compression numbers (they were 195-200 overall) I'd leave the shims out and take another compression check to see which ones were the lower ones....The last time the motor was run it was with the 030 shims, but had sat apart for 2 days since...well, Cold, without shims #1 where the lowest spring height of 030 was came to 210 lbs. the others on that bank came up with zero, as did #8 then I quit, figuring the lifters did'nt beed down and were still at 030 height and I might hurt something and so let it sit together overnite, now this morning I got 180 to 190 in all cylinders..runs ok but vacum readings were back to where they were in the first place and vibration still there......but that 210 reading has got me think'in...I'm just not sure about what....I'm gonna take it to a shop with a osciioscope today to see if he can identify which cyl. or at least area may be the culprit....feel free to chime in I got lots of opinions and ideas but still need more....kind like Bp with out all the money!....thanks, cliff

Warhead

Good luck-
Keep us posted.
Jim

vettemad

Jim,..That's it? I thought you'd have more to say....I just got back from the guy who was gonna do the oscilloscope test my builder sent me too and he says he does'nt think theres anything wrong with the motor he thinks it's bad mounts.....yeah sure, him and the builder are probably in bed together on this...I know they ain't broken but they may be petrified so I looked into mounts(to cover all the bases) for a 70 toro and nobody shows em, they all show side mounts and are calling them 1970 toronado....which ain't right! of course we all know there's on big one in front center and two smaller ones on the sides of trans in back...they probably want to convert me to the side mounts but still don't offer the trans mounts...what about the vacuum diagram...you got one?....thanks, cliff

Warhead

With those verified compression readings, I think you are ok on the valvetrain.
It's hard to diagnose from this end, that is why I said to get someone on the fender. If you think he is full of it, he probably is. Maybe a second opinion would be in order here. You can usually tell when someone does NOT want to work on your vehicle.
Vibration is coming from somewhere, very likely to be connected to the errant vacuum reading.
*** That 455 should run smooth.***
Without seeing it myself...I can not say much more, except to look for vacuum leaks. A pair of needle nose pliers work great for pinching rubber vacuum lines. Carb cleaner sprayed around the base of the carb will reveal a world of loose gasket issues.
Sorry I can not be of any more help.
Jim