Crazee build

[Crazee D]

Yah, my piggyback wont be able to deal with that

 

[Crazee D]

Have you pics of how you cut the 626 valve cover?

Mine I bought recently from XelderX...

 

[bazooka joe]

(cool)

 

[altspace]

woot!

 

[Crazee D]

So I spoke with the shop again (http://candcperformancefabrication.com/ ) since I've been nagging for an update.
Cylinder head was sent WAY off cape to somewhere in Western mass.
(monkey2)
That shop is doing the decking, valve and valve seat work.
They finished the intake side so far. So about halfway done before it comes back for the port work.
The valve and seat work apparently / obviously also affects lift which affects our lash measurements.

Let's talk about what I am learning regarding lash...(ughdance)
Apparently aftermarket cams often CANNOT be set back to OEM tolerances.
This race shop uses a technique of trimming the valve stems along with shimming (I assume) to adjust lash.

 

[Tom03es]

^^Interesting. I wonder if that's just because they don't have the amount and variety of shims that a Mazda dealership might/should have.

So with the fatter cams installed, is the valve lash too tight now with your original shims?

 

[LordWorm]

So I spoke with the shop again (http://candcperformancefabrication.com/ ) since I've been nagging for an update.
Cylinder head was sent WAY off cape to somewhere in Western mass.
(monkey2)
That shop is doing the decking, valve and valve seat work.
They finished the intake side so far. So about halfway done before it comes back for the port work.
The valve and seat work apparently / obviously also affects lift which affects our lash measurements.

Let's talk about what I am learning regarding lash...(ughdance)
Apparently aftermarket cams often CANNOT be set back to OEM tolerances.
This race shop uses a technique of trimming the valve stems along with shimming (I assume) to adjust lash.

The cams are not designed to operate with OEM lash though.... and no attempt should be made (especially on the exhaust side, which has a deliberately reduced base circle) to get them to OEM lash specs.... The lash figures you are after are in the original GB thread and in the install thread - if you go for OEM lash you'll be miles too tight....New lash numbers were worked out by the cam manufacturer taking into account the new ramp rate (which is very aggressive compared to the OEM cams) and base circle diameters...

also - have your head guys considered making custom shimless buckets? might be something to consider - less mass in the valve train etc - meaning less flogging the springs, less parasitic loss etc...

 

[Crazee D]

Link to lash discussion in Twiggy install thread:
http://www.mazdas247.com/forum/showthread.php?p=3208603&highlight=lash#post3208603

^^Interesting. I wonder if that's just because they don't have the amount and variety of shims that a Mazda dealership might/should have.

Yeah, this way they can avoid the cost of those shim kits

So with the fatter cams installed, is the valve lash too tight now with your original shims?

I'm not sure thats how to explain it.
I think its more that the changed base circle of the cam lobes means they can no longer safely run at OEM lash spec.
They have to be looser to run the more aggressive ramp profile and not wear a channel into the cam lobes.

Someone please correct me if I'm wrong cuz I'm new to learning about this.

The cams are not designed to operate with OEM lash though.... and no attempt should be made (especially on the exhaust side, which has a deliberately reduced (????) base circle) to get them to OEM lash specs....
The lash figures you are after are in the original GB thread and in the install thread

Please help me find and re-post these.

- if you go for OEM lash you'll be miles too tight....New lash numbers were worked out by the cam manufacturer taking into account the new ramp rate (which is very aggressive compared to the OEM cams) and base circle diameters...

also - have your head guys considered making custom shimless buckets? might be something to consider - less mass in the valve train etc - meaning less flogging the springs, less parasitic loss etc...

Are these all the same numbers? What are they?
What's a shimless bucket?

 

[FL_PR5]

Interested in these questions as well. Subbin, for future reference on the a NA build of my own...(sssh)

 

[AusOrion]

Please help me find and re-post these.

Here you go:
http://www.mazdas247.com/forum/showthread.php?p=2929337&highlight=lash#post2929337

My Twiggy cams went straight in. Some of the shims had to be moved around to get a better fit but nothing major.

 

[ForceFed]

90HP on your previous Dyno...Wow....My damn Bike puts down 111 to the wheel!

 

[LordWorm]

words...

Base circle on the exhaust cam was reduced below the OEM cam base circle to (from memory) accomodate the lift and ramp rates without getting clearance issues.

Base circle is just that...the base circle that the lobe profile is ground from. If you were to imagine a lobe sitting on your desk - if you project a circle, using the radius to the point that is the furtherest distance from the centre of the lobe, you get the base circle.

Ramp rate is more or less the rate at which the lobe opens the valve. Theres certainly a lot more to it...i'll try and find some literature for you.

You don't need base circle numbers etc to work out the lash requirements, the cam manufacturer has already done this for you - follow AusOrion's link and you'll have all the info you need (you MAY need a few shims from mazda to get it all within tollerences, but you could get lucky and just have to move a few around to get it right).

Shimless buckets are just that.... custom built buckets that provide you the exact lash you need and don't require shims.... not cheap, and usually reserved for race motors - but if you are already going that far . . . . . . .

 

[Crazee D]

Thank you, thats what i was lookin for.

LASH (important).
Intake should be set between 0.010 and 0.014
Exhaust should be set between 0.020 and 0.024 please note this is perfectly fine when you check your lash. If youre wondering, the reason for the higher lash is to get the ramp rates back into an acceptable range.

 

[Crazee D]

update...

Innovate LC-1 is here! Woot!
Came with a serial cable...boo!

 

[bazooka joe]

serial???(scratch) that's dumb!

 

[Sleepy]

I had to buy a serial to USB converter because my laptop doesn't have a serial input. No big deal though. The LC-1 in my car has been very useful and reliable for over a year now. The 2 programmable analog outputs have come in handy. My wife just likes the pretty lights, but I installed it in the cup holder and shut the lid when I don't want it to be seen.

 

[Crazee D]

This appears to be a rather complex tuning tool. I loaded some of the software earlier.
It will be a challenge for me to come up to speed on this.
Any advice or guidance?
I got to join the Innovate forum now too, I'm already on the AEM one.

 

[Crazee D]

Ofc I sold my $70 Radioshack serial to usb converter along with my MPI

figures.

Called shop again today for update on head, he will call them.

 

[Sleepy]

I can't remember having any trouble setting it up, or much else about it, it's been that long. There is plenty of instruction and info with the kit. Make sure that the plugs are pushed in hard (get the 'click')and don't put any side load on the plugs. The only time I thought it had failed turned out to be my poor location of a plug allowed passenger foot pressure to loose the connection to the gauge.

I use one analog out to provide a narrowband signal to the ECU and the other for wideband signal to the emanage for tuning. The preprogrammed narrowband worked fine for my ECU.

As a quick install, the XD16 can be mounted in the cup holder(don't know if yours is the same place though) on a toilet roll cut to fit and angled as desired.

The stamped in/out plugs can be difficult to sort out in low light, so tags could help when changing stuff.

 

[Crazee D]

Thanks mate!