NA8A Lifter Issues

manga_blue · Postby **manga_blue** » Sun Jul 12, 2015 1:25 am

Vern, I'm interested in the cams. I've been thinking about just dropping in NB cams for a while. I've had it up to here with HLAs, even if I'm apparently just stepping around a different problem.

madjak · Postby **madjak** » Sun Jul 12, 2015 1:31 am

tbro wrote:Remember these aren't cosworth engines, these are motors designed for a 323/ Laser hatch/sedan, not designed to rev for 1 hour at 8000 rpm and come back the next day for more of the same, these are mass produced family car engines that date back to the 60/70s????.The fact that we can race them is testament to the designers abilities

Thats my 2c worth!!
T

They are based off a BDA cosworth engine though. Very similar design, 4 ports per cylinder, twin cam, cross flow head... same as the toyota, ford, honda engines of the same era. What works on them works on our engines. Replace the weak points and put in similar cams and you can pretty much match the power per litre of the original BDA. Only thing you can't get close to is the revs.

project.r.racing · Postby **project.r.racing** » Sun Jul 12, 2015 9:27 am

manga_blue wrote:Vern, I'm interested in the cams. I've been thinking about just dropping in NB cams for a while. I've had it up to here with HLAs, even if I'm apparently just stepping around a different problem.

just to throw a plan B at you. 96-98 Astina BP engines also had solid lifters. The lifters are the same as NB lifters, but the camshafts are different profiles. slightly less duration (on the exh cam) and overlap, but a shiz more lift on both cams. more torque and lower by 500rpm over the original NA8 motor, but guessing there will be breathing issues above 7000.

it depends on the plan for the car. track work looking for high rpms, stick with MX5 camshafts, motorkhana or autocross, astima camshafts might be the go.

pcmx5 · Postby **pcmx5** » Tue Jul 14, 2015 12:04 am

Ok, totally confused,which is not hard to do!! I have Tighe 805C cams and have purchased Mazda Speed motor Sport Developments shim-under-bucket solid lifters and when I can work out what I need Supertech lash caps which will be ordered after doing a test assembly.
As per my original post I tried to get Wazza to do the job in Dec 2013 but he couldn't. Did the head and have had constant HDLA issues since.So went the solid lifter route after consultation with Dalton Automotive here in Geelong.

Their head supplier has no idea what to do ,can anyone throw any light on the settings he needs to do to use the solid lifters?

Wazza are you out there? Anyone who has gone this route and has any REAL experience pls help!!!

Peter.

pcmx5 · Postby **pcmx5** » Tue Jul 14, 2015 12:06 pm

Ok, done the research I should have done before buying the solids. Tighe say it would be stupid to use them as they really not suitable for their cams and if you did put them in the motor would be as rattly as hell.

So a set of solids will be for sale and I will be going back to HDLA's!!!

Peter.

project.r.racing · Postby **project.r.racing** » Tue Jul 14, 2015 5:05 pm

or you sell the 805Cs and buy something suited to your liking and goals. 805Cs and F-cams are good for finding a few extra killer wasps and rpm. But if aiming or bigger engine power gains, you'll need to go past them.

pcmx5 · Postby **pcmx5** » Tue Jul 14, 2015 5:56 pm

Happy with the 805C's and my power output but not with the lifter noise which was the motivation to go solids.Have fitted stronger valve springs so will try some other HLA's and hold my breath. Realistically don't need to go over 7000 so hope all is good.

Thanks everyone for your input to this thread.

Peter.

pcmx5 · Postby **pcmx5** » Wed Jul 15, 2015 6:27 pm

I am going back to HlA's with new stronger valve springs.The head guy said the valve springs really didn't have much tension and a few of the lifters had collapsed!! They had only been in there for about 8000 klms and were from the US and cost about $300 for the set but i guess if the springs were stuffed this may have effected the lifters.

hopefully all back together and running well(and quietly) by the WE!! Will impose a 7000 rpm limit.

Peter.

StillIC · Postby **StillIC** » Mon Aug 10, 2015 9:10 pm

Timely thread....
I have started hearing the dreaded rattle for far longer than normal for the last couple of weeks. I pulled the cam cover on the weekend to find two soft HLAs...one on the exhaust and one on the intake. Bugger. One can be compressed a good 2mm, the other less than 1mm. As of yesterday (state supersprint) the engine is very rattly. Mostly at low revs, but I think there is too much exhaust noise to hear what is happening at high revs. I also think they are causing a surging/retarding when rushing up through the revs, sometimes barely noticeable, sometimes very noticeable after running at constant speed on the highway.

I am running a B6 with Kelford cams: -1mm base circle, 10.0mm lift, 272Ex/280In duration and a spring poundage of 65 seated and 175 at full lift. I rev to 8000rpm in every gear on the track. The HLAs are less than 6000km old.

I have a feeling that a couple of the new HLAs were dodgy straight out of the package. Some of them were soft and I assumed they would pump up, which they did (initially?). I wish I recorded which valves I put the dodgy HLAs on when I rebuilt the engine 1.5 years ago.

Anyway, I am not sure I could be bothered pulling both cams out, replacing 2 HLAs only to have this issue happen again at any time. Do I do a Manga Blue and start rebuilding a solid lifter head? Do I back off on the seat poundage and continue running to 8000rpm (I was planning on revving faster, and this is a head off exercise)? What else?

manga_blue · Postby **manga_blue** » Tue Aug 11, 2015 2:44 pm

I can't see how you've got any options if you want to spin to 8000 and beyond. HLAs won't work at those speeds, even if you assist with oil supply. You need lightweight shim unders, solid profile cams and quality springs.

madjak · Postby **madjak** » Tue Aug 11, 2015 2:58 pm

My BP motor is running Eibach dual springs, solid lifters with big lift and duration cams. I'm reving it to 8300 which might be pushing it a bit, but the engine feels like it wants to go there. I know the previous owner had some valve float issues above 8300 even with the heavy springs which damaged the valve seats on the intake side.

Not sure if that's helpful or not! I know doesn't really apply to a B6. My B-spec 1.6 revs to 7800 rpm with the mazdaspeed ECU with HLAs without any issues. I have no idea what the cams are but they aren't stock B6. They come in at 5500 rpm.

zossy1 · Postby **zossy1** » Tue Aug 11, 2015 4:42 pm

The HLAs have benefits on a daily, but when you're talking those kind of rpm goals I'm fully in agreement with Phil. Solid SUB lifters are a must.

They can be a pain to keep in adjustment but that is the price you pay for spinning a B series engine that hard.

I hope you have forged rods in that engine...

manga_blue · Postby **manga_blue** » Tue Aug 11, 2015 7:08 pm

The good thing for you, Scott, is that B6 heads are cheap and freely available. Building one up on the bench while you've still got one going in the car shouldn't be too hard and it would mean no stress and no missed meetings.

pcmx5 · Postby **pcmx5** » Tue Aug 11, 2015 7:17 pm

[quote="manga_blue"]The good thing for you, Scott, is that B6 heads are cheap and freely available.
Unlike BP heads!! After 800 klms on a new set of lifters mine is rattling again worse than ever!!!!
To say I'm PD off is an understatement.

Peter.

StillIC · Postby **StillIC** » Tue Aug 11, 2015 9:16 pm

manga_blue wrote:The good thing for you, Scott, is that B6 heads are cheap and freely available. Building one up on the bench while you've still got one going in the car shouldn't be too hard and it would mean no stress and no missed meetings.

I think I mentioned in another thread that I am on my 6th head, and of those only 1 is hard (the one on my engine!), 4 soft and 1 marginal. Plus, building another head is many hours of porting, new valves, machining, new springs and retainers, new expensive head gasket (non standard thickness) plus the new buckets and cams. And a couple of days to change over.

I am thinking I may go the solid lifter and new cams, and just spend the time setting them up in the car on the existing head after the 2015 season ends. I may just replace the 2 dodgy HLAs and keep going for now. But even so it is a timing cover off, belt off, cams off job. I have spent too much time in my life working on cars.

Thanks everyone.

BTW, does anyone have any good info regarding seat poundage requirements for ~8300rpm? Supertech/949Racing quote different numbers to FlyinMiata, which are all different to my engine guy whose numbers are highest, hence the 65 pounds.