Notice: We request that you don't just set up a new account at this time if you are a previous user. If you used to be one of our moderators, please feel free to reach out to Chris via the facebook Outerlimits4x4 group and he will get you set back up with access should he need you.
Recovery:If you cannot access your old email address and don't remember your password, please click here to log a change of email address so you can do a password reset.
I just rebuilt a stock 3.5lt (8.13:1) mtr in a '84 rangie, it's got the 14 bolt heads with tin gaskets, from factory (i think). The only pistons I could find that would balance were 20 thou oversize 9.35:1, and I used composite head gaskets when I put it back together.
I replace all the valves and springs, rocker gear and shafts, lifters, cam and it rattles a bit....
I took off the rocker covers to retension the heads (which didn't budge) and to investigate and found that I now have 10-20 thou clearance between the top of the valves and the rockers?
In one of the other posts there was mention of taking 35 thou off the rocker shaft pedastals......should I do this?
G`day Stevo , you`ll have to take or leave what i say because you`ve really got work it out yourself but we know that anyway , will try to help .
On a 3.5 i think the diff is .6 so a very broad around 8.75 : 1.
Will depend on which comp gaskets used , the ones i`ve measured are Fel Pro blue 45 thou compressed .... Rover 52 thou compressed .
The figs for 3.5 comp gaskets on the WEB are 40 thou compressed , this is where the take or leave is because i cant get close to the WEB figs .
Though the tin gasket i get the same 20 thou as the WEB figs .
Combustion chambers on 3.5 heads that i`ve measured are more like in the range of 37 - 38 cc . The figs on the web are 34 - 36 cc
The accepted way is to measure the lifter preload generally in the range of 20 - 60 thou , it`s the distance the pushrod sits inside the lifter and of coarse the inlet manifold and gasket have to be off and the lifters need to have the oil drained from them .
I pressume the 10 - 20 thou you`ve found is with the lifters on the back of the cam so that means it has no preload at all and so the rattle will only get worse as it wears . The clearence you`ve found between the valve and rocker may or maynot relate to the clearence between the pushrod and lifter seat .
I know the rover manuals don`t mention lifter preload and unless there`s a problem , it wouldn`t be given a second thought .
Before you start taking metal off the posts i`d suggest and ask .
What is the engine number prefix on the 84 8.13:1 if the original engine should be 9.35:1 ?
Which type comp gaskets did you use ?
Which type of lifters did you use , Rover , Factory GMH , Aftermarket holden ?
With the rocker gear off put a straight edge across the valve stem ends and make sure they are even .
There are different types of rocker arms some are angled left and right and some are straight but the pads are left and right as well as not seating on the valve properly it can also hinder the lubrication of the valve gear if there arse about .
did you check your deck height ?
it could be the pistons kissing the head not the valves.
also - i wouldn't go machining posts until you check the valve train geometry. reground heads, remachined cams etc all will affect it.
if its way out you will wear the guides real quick.
what lift cam? durations etc. is the cam timmed right?
i would pull the heads off real quick and have a visual inspection.
Ex-Army - SeriesIII -186s - NP435 - Maxi rear - megasquirt coilpack ignition - AM FM radio with 2 X speakers
if you have 9.35 pisons to a 8.13 engine it is now 9.35 as the only difference is teh pistons. The heads of teh same model 8.13 and 9.35 are teh same.
If you have added composites then this has caused the lack of preload.
If you have 10-20 thou clearance, then you need 20 to 40 thou PRELOAD AT THE LIFTER , between the lifter and pushrod. ie the plunger in the lifter has to be 20-40 thou below the circlip. Now your rocker ratio is 1.5 :1 so your 10-20 gap at the valve is 3/4 of this at the lifter.
SO if you have say 5 thou clearance at the lifter you have to change this by 5thou plus 20 thou minimum. Probably taking 35 thou from the pedestal will fix it.
While Peter R has good points, if you have done exactly what you said you did you should not have valve clearance problems, just the preload.
Regards Philip A
I'm fairly certain (hopeful) that the heads and block haven't been machined.
I used the genuine rover comp head gaskets and i originally had the GMH lifters (which were supplied by Crow Cams with the new cam) and changed them to genuine rover ones (after about 5000kms) thinking that was the problem.
Doing this did reduce the noise slightly.
I think I will try taking 35thou off the rocker shaft pedestals, as I can get them cheap if it doesn't work and I then need to go deeper.
G`day , i`d suggest you don`t overlook popeyes valid point about train geometry .
You have me intrigued .
I have 3 x3.5s here one had tin one had comp one had both ( at different times ) none rattled or have had there posts machined . Two have had there heads machined but the one that ran comp has only been skimmed .
Two are 9.35 stamped one is 8.13 stamped but has 9.35 pistons .
All engines are different to some extent but it is uncommon to have to machine posts , very common to fit shims .
AFAIK your 84 should have a 9.35 stamped engine and should have ERC 0216 heads but you say yours is 8.13 . my 8.13 stamped is from an SD1 not a RR but the main bulk is the same .
If yours has 2 numbers and a letter as its engine no prefix and ERC 0216 heads , not a concern ...... but if it has 3 numbers as its prefix and other heads ..... it may have the smaller valves ( heads ) and if you ordered valves for an 84 and got them to fit in these heads ( don`t know if poss )
the installed height won`t be right , as in too low and extra clearance .
Just trying to understand where the extra has come from , at most there`s around 30 thou difference between the gaskets ( my reckoning )
Maybe the cam base circle is smaller
maybe his valve installed heights are lower
Maybe his lifters are shorter, perhaps after market for something else masquerading as Rover.
Plus some caused by thicker gaskets. If he is plus 30thou ( ie +20 thou min preload plus a gap of 10thou at the lifter) and he was at the lower end of preload 20 thou it is conceivable it is all caused by the gasket. Remember he was measuring at the valve which is 1.5 times at the lifter.
Now I am not sure of this but I believe that even if it is caused by something else, by machining the rocker posts , he will restore the relationships. I do not think he can cause problems BUt of course it is his call we can only advise.
Gee it must have a tiny valve lift and overlap at 20thou clearance!!!
Regards Philip A
G`day Philip , yes unless all the infomation is there , i certainly couldn`t hazzard a guess and i have a feeling it`s not forthcoming so another wonderment .
When i was cam searching i noticed most ( prefer these to off the shelf )cam places say 1.5 and AFAIK the 4.4 is . Rover reckon 1.6 .
[quote="peter r"]G`day , i`d suggest you don`t overlook popeyes valid point about train geometry .
You have me intrigued .
I have 3 x3.5s here one had tin one had comp one had both ( at different times ) none rattled or have had there posts machined . Two have had there heads machined but the one that ran comp has only been skimmed .
Two are 9.35 stamped one is 8.13 stamped but has 9.35 pistons .
All engines are different to some extent but it is uncommon to have to machine posts , very common to fit shims .
AFAIK your 84 should have a 9.35 stamped engine and should have ERC 0216 heads but you say yours is 8.13 . my 8.13 stamped is from an SD1 not a RR but the main bulk is the same .
If yours has 2 numbers and a letter as its engine no prefix and ERC 0216 heads , not a concern ...... but if it has 3 numbers as its prefix and other heads ..... it may have the smaller valves ( heads ) and if you ordered valves for an 84 and got them to fit in these heads ( don`t know if poss )
the installed height won`t be right , as in too low and extra clearance .
Just trying to understand where the extra has come from , at most there`s around 30 thou difference between the gaskets ( my reckoning )
Thanks , peter[/quote]
Well I did the deed and took off the 35 thou from the rocker shaft peddestals, and it works a treat, no more tappity tap tap.
Just for your info the block I have may have come out of an earlier car as it stamped 8.13 and by the eng# looks to be a '78 model, the heads are the ERC 0216. Anyway thanks for the info, I'm goin to take it for a test in some mud this weekend and see how it goes.
