Assuming I had the supporting valvetrain and cams, what is the maximum rpm the HLA's could take before I needed to start worrying about them collapsing?

 

I don't have any other input on that topic. But is there a way for you to convert to solid lifters like my motor?

 

I did a little reading up on the limiting factors for the rev limit on the 1.6 about a year ago. I seem to recall that it was one of the first things that limit the revs on the motor, and they start to have problems around 7800rpm .. or was it 7600? I just remember that the recipe for 9k rpm was oil pump gears, solid lifters, and upgraded rods ... or something like that.

I dont remember if you were going FE or BP motor for your build, but it is possible that the BP solid lifters will fit in the FE. .... a 9krpm 2.x FE would be sex in the miata gl with you build

 

toda makes a solid lifter conversion the 1.6 NB's are solid lifter as well. I would check with them and see if they are the same.

 

hes building his 1.6L

 

Float definitely occurs closer to 7k than 8k. Conversion to the 99+ solid lifters is the same for the 1.6, but you'll want some solid lifter cams. I'd think that the 99 valve train parts would be fairly cheap now that the cars are 8 years old. The only problem with the OE shim-on-bucket solid lifter is the weight. Over 8k and there's a risk of spitting out a shim.

 

dont think 1.8 cams will fit a 1.6....

what years had shim under bucket?

 

Nope. There's probably a Jap shop that made solid lifter cams though... chi-ching. Shim-under-bucket wasn't available stock- but you can buy the setup from Mazdaspeed. Though it's pricey. I ran the Mazdaspeed Production shim-under-bucket valvetrain in my 99. We used a shim on the lifter bucket pedestal and then made another from drill rod to sit on the valve stem. This compensated for the cam base circle change. You set the valve lash by grinding the drill rod shims to fit. It worked great - car rev'd like a motorcycle.

I'm sure hla 1.6 cams could be cut for solid lifters and then just adjust the base circle as we did. I doubt the cams we ran were cut from blanks- since we too had to compensate for the base circle difference from stock. Though it could have been for the differences in valvetrain from the 1.6 to the 99 1.8 valvetrain. Time to get measuring.

 

What is the difference between cams made for hlas and solid lifters? They all look the same to me I'm sure that any company that makes cams could do the extra work easily. I know crower does cam grinds for a decent price.

 

if you tell the cam grinder you have solid/hydraulic lifters they will make sure the profile is compatible. It has to do with the ramp up rates going from closed to open and the ramp down rates in the opposite direction. That's about all I know.

 

The solid lifter cam (left) provides a more progressive transition to peak (and longer duration). Running the hla cam profile would be harsh on the solid shim.

 

Gotcha, I emailed you rob.

 

I know it would probably be impossible to find but.... what about the B6T motor out of the 323 gtx... wouldn't that have used solids?

Dave,

 

They had hla's also

 

can anyone with a mazdaspeed membership get me a price on the solid shim under bucket lifters each, and on the shims? I wanna get one to check out and take measurements.

 

I know that is why i referenced several 1.6 examples i hope this works i so want it for my self. 10K rpm would be sweet if i could figure a way to not split the block :gay:

 

I have someone sending me a pair of mazdaspeed shim under buckets. I will make a new thread when they arrive detailing what needs to be done to make them work.

 

I am in the process of porting, new larger valves, stiffer springs, and probably a .050" shave to increase compression. I have sent a pair of cams to the cam grinder, and they say they will take approx .080" off the base circle to get max lift and duration. They are grinding for mechanical lifters. I should get about 260 deg advertised and 214deg duration at .050" lift with .375" lift (9.5mm) total.

I bought one shim over bucket lifter, and one shim, so I can measure what clearance I will have. Then I will order a full set of shim under bucket lifters and shims. I will be ordering slightly larger shims than what are required. I will then assemble without springs and check the clearances, and hope to be able to trim the tips of the valves to get the proper clearances. The shims themselves may be able to be ground, but until I have them, I dont know how I would be able to chuck them into the valve grinder to trim them. I have read it is possible, and would prefer that way, rather than to trim the valve tips.

The reason I will have to go through all of this, is because it appears the shim sets (cheaper to buy a set) can only be purchased as a set of one size. My labor is free.

I will keep you posted on my progress.

Ron

 

awsome yes please keep us updated.