13 replies to this topic

[octagonalpaul]

998 engine, 12g295 head, Swiftune SW5 cam. Cam followers were replaced when new cam was put in 5 months ago, has driven fine up until head gasket went between cylinder 2 and 3.


I've done the head gasket on the mini, and think I've managed to completely poo up my engine.. done it before and this has never happened any other time!
When taking the head off 3 pushrods came up and shifted the cam followers, which was annoying. The number 7 cam follower was more difficult to put back in than the others, but it did go in eventually. Problem is, now the rest is back together the number 7 valve never fully closes, and opens further than the others. What have I done ? The engine does still run but is very lumpy and I don't want to run it after hearing that for fear of causing huge damage. Thanks in advance!

[carbon]

Are you sure that the number 7 cam follower went back in the right way up?

[dklawson]

I don't understand. Are you saying that when you pulled the cylinder head and removed the pushrods, three of the pushrods stayed "in" the top of the followers and when you lifted them, the pushrods pulled the followers out of their bores?

You said you have replaced head gaskets before and that this has never happened before. Please do not take offense at this question, but did you adjust the valves after fitting the new head gasket? As you probably know, no two gaskets will compress the exact same amount so you need to adjust the valves any time a new head gasket is fitted.

[racingenglishcars]

Sounds like the lifter went in wrong way over. If so you can fortunately remove the cover and flip it, though it might be a VERY tight squeeze getting your fingers in there.

[Cooperman]

If the cam follower has turned upside down it is unlikely the rocker shaft would actually fit back on.
Have the valve clearances been re-adjusted to 0.012" cold after the head was torqued down, using the 'rule-of-nine' sequence for re-setting.

[octagonalpaul]

Cam follower is the correct way up, valve clearances all done except the number 7 valve as when number 2 is out number 7 doesn't come all the way back in. Sorry, it's difficult to explain! Not possible to set clearance for number 7 valve as it's never all the way in.

[Cooperman]

You need to remove the cam chest covers on the rear of the block and check that the followers are all seated correctly. It's easy once the inlet manifold is off.
If the follower is not seated correctly you need to re-fit it and as this means taking the push rod out then the rocker shaft will need to be removed and hence the head sould also be taken off again and a new head gasket fitted.
Do it all in sequence and check at each stage.

[ANON]

should be able to slacken it right off and slide the arm to one side to get the pushrod out.


edit...i think you should anyway??...i'm not going to google a pick of a set of mini rockers, honest

Edited by ANON, 02 January 2013 - 07:13 PM.

[jaydee]

Problem is, now the rest is back together the number 7 valve never fully closes, and opens further than the others. What have I done ? The engine does still run but is very lumpy and I don't want to run it after hearing that for fear of causing huge damage. Thanks in advance!

Sounds like the rocker adjuster istn seated properly on the pushrod
You've properly bent the pushrod now
Also dont forget to reset tappet clearance

[octagonalpaul]

I had the covers removed to ensure they all sat in properly, will check again though in case something shifted the number 7 one afterwards. Thanks for all the help so far!

Edit:
It's all seated properly up the top end, will have another look and try and get some pictures

Edited by octagonalpaul, 02 January 2013 - 07:15 PM.

[octagonalpaul]

Ah. All fixed now, and I feel like a total idiot! Here's what happens when you have too many car bits.. somewhere along the line a 1275 pushrod worked its way into my organised set of 998 ones to go back into the engine

I have no idea how I actually managed to do that, but the moral of the story is be more careful when putting bits to one side! Luckily there doesn't seem to be any damage yet, but I'll keep my fingers crossed and be more careful in the future. D'oh

[ANON]

these things happen

i was stripping a midget engine the other day, i thought 'no one would ship an engine with oil in it' but got a pump through the dipstick hole and managed to suck half a cup full out, then proceeded to strip it. lay it on it's side to take the sump off but had to answer the call of nature and left it just about long enough for it to spill about 3 litres of oil all over my spotless engine bench!!

[KernowCooper]

Boy you were lucky on piston to valve clearance or it could have been a head off again !

[dklawson]

Great! I'm glad you found the problem and sorted it without any apparent damage.