NA8A Lifter Issues

[pcmx5]

My NA did well over 100,000 klms on the original lifters that then developed a ticking noise and were replaced with Kia ones.These only lasted about 10,00klms before they rattled too.When the head was off for some work new expensive $300 plus ones from the US were fitted and less than 5,000 klm they rattle on most start ups and almost every time the car is taken over 5,000 rpm.Sometimes it is perfect but most times noisy.It is driving me crazy(ier!)

Car is running Penrite HPR 30 and I have tried some Nulon lifter clean with no effect.Have fitted a proper oil gauge and it is running between 45 and 65 PSI hot under load and 25-30 at idle..

Cheapest way would be to fit another set of lifters but am wondering if i have another issue .I am considering Mazdaspeed SUB's (to convert to solid lifters)but that will end up costing around $700 to source and fit plus the car will be off the road for a while as the buckets need to be put in and then measured for the correct lashes to be ordered.

Has anyone had experience of another cause for this eg. blocked oil ways?

Peter.

[manga_blue]

Yep, they're the bane of my existence. Kia HLAs are identical to Mazda HLAs. They are most likely not your problem. It's in the head and cam setup.

Have a close look at an HLA to see how it works. You'll notice there's a groove around the outside about half way up. The purpose of that groove is to transfer oil via the oil feed hole in the lifter bore from the gallery to the centre of the lifter, no matter which way the lifter is currently rotated. With a standard cam that groove should sit on about the same level as the oil feed hole for most of the cam rotation, excepting of course when the cam lobe depresses the lifter below that hole. This means that the lifter has a pressurised oil supply for around 210 deg of the cam rotation.

If you have a reground camshaft with a smaller base circle diameter then the lifter sits higher in its bore when not depressed and it may have inadequate feed from the gallery because the groove is above the feed hole for almost the entire cam rotation. This usually manifests itself as oil starvation, heard as thrashing, at higher RPM, as opposed to the more common lifter problem of clicking at idle on start-up. Coming down the main straight against the pit wall at Wakefield I've heard my car sounding like a chaff cutter.

You have three options:
1. Swap to cams with standard BCD
2. Take the cams off and open out the feed hole in the head with a channel or groove extending at least as far up from the original hole as the decrease in BCD in your cams. Wozzah can advise on this.
3. Swap to Mazdaspeed shim under lifters. If you do that then you must also change the cams because the cam profiles for HLAs are totally unsuitable for solids (search this site for posts by me on breaking valve springs )

Option 2 is worth doing in any case. I've had several NA8 heads and the positioning of those feed holes with respect to the groove in the lifters has been wrong in some and they've needed the holes opened just to work at high RPM with standard cams.

[pcmx5]

Thank you Manga for the great in depth reply and sharing your experience,really appreciated.

My cams are Tighe 805c and they are bullet cams so will have to check the diameter.Only doubt here is that the 805c's were in the car for about 50,000klms with the original lifters and i never had the issues I am experiencing now so in my non mechanical mind I cannot work out why all of a sudden things have changed.Head work was only a mild port and polish and slightly bigger exhaust valves.

I seem to be suffering both at low speed and more recently(remember after about 5000 klms of silence) the new high speed rattle.

Thanks again plenty there for me to pursue with my mechanic.

Peter.

[pcmx5]

Tighe's say that they are the standard Mazda base circle diameter..

Peter.

[manga_blue]

You've got me stumped, Peter. I'd try getting in touch with Wozzah. I think he has messed around with lifters on higher revving BP motors a fair bit.

As for me, I've had enough of HLAs. Never want to see or hear them again. I'm quietly sourcing parts to build a new HLA-free head which I can just swap in in a couple of hours when it's ready.

[pcmx5]

Thanks Manga,i'm stumped too(but that's not that hard).

Will make sure i do not have any valve spring issues and then probably try some more HLA's. Are absolutely sure that I cannot convert to SUB's with my current cam?

I also forgot to mention that the exhaust is not as crisp when the noise is there and it feels to lose some power.

Thanks again,

Peter.

[manga_blue]

Happens with mine too. I lose a lot of power when it's thrashing. Loss of valve lift I think. This car is redlined at 7600 and I use 7500 for almost every shift. Starvation tends to build up over a few laps. By about lap 3 or 4 it's buggered.

Speak to any cam builder about the profiles. I think you'll get the same story.

FWIW the history of mine was I first replaced the HLAs with a good second hand set, almost no improvement. Then opened out the oil holes, about 25% improvement. Then installed brand new HLAs, another 10-20%. Trouble is that I needed a 100%.

Is anybody else getting this?

[sailaholic]

What valves did you go? I did supertech 1mm oversize. The valve stem is a different length and required different shims fitted to the hlas by wozzah. Maybe similar had happened to yours and the correct adjustment not made?

Manga, I believe Gary Stewart just shims up the hlas for many of his builds.

[project.r.racing]

The HLAs dont really like going past 7000rpm regularly. If you do, it's time to invest in solids.

[manga_blue]

What valves did you go? I did supertech 1mm oversize. The valve stem is a different length and required different shims fitted to the hlas by wozzah. Maybe similar had happened to yours and the correct adjustment not made?

Stock NA8 valves. This is not a highly modified motor.

Manga, I believe Gary Stewart just shims up the hlas for many of his builds.

Now that's an interesting concept. Does that mean that the HLAs won't work properly because a reduced BCD extends their length beyond the normal range, rather than being starved of oil by sitting above the feed hole. If that's the case I've got a box full of lash caps ....

The HLAs dont really like going past 7000rpm regularly. If you do, it's time to invest in solids.

Yes, well, I was told HLAs were good to 7800 with very mild cams. Until sailaholic's little comment about Gary Stewart I thought I'd pretty well proven that was wrong and you're right. Hence the shelf in the shed filling up with head parts.

[pcmx5]

[quote="sailaholic"]What valves did you go? I did supertech 1mm oversize. The valve stem is a different length and required different shims fitted to the hlas by wozzah. Maybe similar had happened to yours and the correct adjustment not made?

Not sure what valves were used but will check.When it is right it makes good power,up to 108RWKW on a fair dyno, but has lost up to 10 RWKW with no real reason a couple of times.The inconsistency is perplexing, perfomance and noise wise.

Wish Wazza had been able to do the job as i really wanted to use his expertise but had a car with an oil leak from the head and waited a couple of months but needed it done.Was done by a supplier to Dalton Automotive here in Geelong .Daltons have a very good reputation and prepare many high performance cars and have built a few BP's.

Just very frustrating as I love the car and have always had it maintained regardless of cost.

Thanks for everyone's input.

Peter.

[sailaholic]

Sorry, miscommunicated that. My understanding is garry shims the hlas to make them solids at a significantly cheaper cost then buying one of the aim under bucket kits. I think garry might have made a passing comment to a friend that hlas should be fine in a non race engine.

In speaking to wozzah he said he ran hlas in his face had for quite a while until he got into the 8000 rpm terrority.

I got confused about the valves, are they bigger exhaust valves or standard na8.

108kw is pretty good! I only got a about 108kw from my dyno. I really need to back to back dyno run someone with these tighe cams.

[manga_blue]

Sorry, we've got our wires crossed. Mine are stock NA8. Not sure what Peter has.

[project.r.racing]

]Now that's an interesting concept. Does that mean that the HLAs won't work properly because a reduced BCD extends their length beyond the normal range, rather than being starved of oil by sitting above the feed hole. If that's the case I've got a box full of lash caps ....

It is not anything new. People have been doing it from the 90s. But it is the same process as SUBs or SOBs, so most just go the correct route in the first place.

[evil_weevil]

Hello all,
I searched the forum before starting a new post...seems it worked out well as I'm having similar issue!

when I got my camtech cams put in back in 2013, car ran great, no lifter noise, managed 94rwkw (NA8) and even managed a 1.118 @ wakefield.
then after a few more track days, the dreaded lifter noise came back.

I am now in the same boat!
people have said its best to switch to solids and also mentioned in here, but does that mean a new set of cams as mine currently in the car are done on the original NA8 ones?

I think solids would fix the issue of the lifters - but hopefully I don't need new cams for it.

I have also suffered loss of power when the noise comes full on.
cheers,
Chris