Los Panchitos heads

[Matt Tobias]

I received my 94 bore 40x35.5 dual spring Panchitos heads from CB and I am curious.  Most everything looks good so far.  They are based on the Mexican 043 casting and have the .040 step.  CCing the heads showed that they counted the step into the overall chamber CCs.  So they are not 59cc as advertised, when I measured the chamber it was closer to 54ccs.  To get my 9.5:1 I had to open the chambers to 60cc. 
I had planned to go .040 in deck anyway for a tight quench so I could have used the step to set my deck but here is where it gets annoying.  When they opened the head up to 94mm, they didnt open up the i.d. of the step so a 94mm piston could fit inside of it.  Therefore my piston would have smacked the head since Im running it flush with the top of the cylinders.  So on a brand new head I had to get the step machined out.  I emailed CB to ask them about this step and havent heard back from them.
Anyone else run into this problem?
Here is a pic of the head after I opened up the chambers.  You can see how small the i.d. of the step is compared to a 94mm cylinder i.d.

[nicolas]

the same step is there on los banditos and idem ditto on the step being too wide (mine are for 90.5).

[leec]

When I emailed CB about an issue with my Wedgeports I did get a reply but it wasn't a useful one

[DKK Ted]

Was gonna get them for a motor I'm doing for a guy, said they didn't have castings, glad I didn't, went with Tims heads.

[Matt Tobias]

Yeah, I probably should have gone with Tims.  Im not disappointed that I got these because I should hit 150hp with plenty o torque, but I was disappointed that a company known for high performance products would advertise these heads as having 59ccs(which they dont have), not mention that they are stepped, and then not even machine them correctly. 
Anyone who gets those heads and doesnt know any better is going to put a .040 or .060 copper gasket in them and end up with .080-.100 deck, thats ridiculous!
If I had known that they had the step I would have had them cut them out before shipping.

[richie]

Yeah, I probably should have gone with Tims.  Im not disappointed that I got these because I should hit 150hp with plenty o torque, but I was disappointed that a company known for high performance products would advertise these heads as having 59ccs(which they dont have), not mention that they are stepped, and then not even machine them correctly. 
Anyone who gets those heads and doesnt know any better is going to put a .040 or .060 copper gasket in them and end up with .080-.100 deck, thats ridiculous!
If I had known that they had the step I would have had them cut them out before shipping.

The step is included in the chamber, that's why it isn't the same size as the piston, its a universal step, the heads come that way stock, yes its not a nice shape for a performance head and doesn't match your requirements but that is included in chamber cc as that is what it is!!  but as with most things in life you get what you pay for

cheers Richie 

[Matt Tobias]

We'll have to disagree on that.  I've never measured that step into the chamber cc's as that area is the quench deck, not the chamber.  A nice tight deck is required to get a good efficient burn in the chamber and thats impossible with that step(Which is why I cut it out and will use a .040 gasket to set my deck).  As far as you get what you pay for, I appreciate you rolling your eyes.  $800 doesn't come easy and if I'd known about the step I would've done things differently.  I'm just letting other people know that if they want to order these heads they should have the step cut out before they leave CB to save them the trouble.  

[richie]

Look at your picture, that whole area is the chamber, to get the cc's you have to measure it all right? compression ratio is calculated using the total area above the piston, it doesn't matter how you get the area[deck height/chamber/piston dish/piston notches etc ] it all adds up to that same total area. Yes the step cut doesn't give the ideal chamber shape, but opening it up just to get cc's often doesn't either.
If that step was cut to allow the piston to fit inside and was 0.040 deep would you be removing it then? No because its the same as using the copper head shim you mention. They advertise them as having 59cc's in the chamber and I am pretty sure they do if you measure it all,

I thought the Los panchitos were only about $650 a pair in 94mm bore?

To warn others about the step is good, but other head shops sell the same thing, lots of 043 castings come like that, I would guess CB didn't put that step in, the head came that way     

cheers Richie

[Pedalpusher]

A pair of SCAT Super D-Ports I purchased last winter had the same step.

Had to just machine it down to get the right deck as I already had 1,5mm deck from top of the cylinder to top of the piston.

Propably they were nearly the same casting or exactly the same.

-Mikko-

[Matt Tobias]

Richie said:
Look at your picture, that whole area is the chamber, to get the cc's you have to measure it all right? compression ratio is calculated using the total area above the piston, it doesn't matter how you get the area[deck height/chamber/piston dish/piston notches etc ] it all adds up to that same total area.

I said:

No, deck height is the distance from the top of the piston at TDC to the flat part of the head, as you know deck height is one of the measurements used in figuring compression ratio along with chamber ccs.  Tight deck is very important to having an efficient engine, which having run an 8 second quarter mile I know you are no stranger to    This universal step as you call it prevents you from setting your deck height with it as the piston will smack the step.  So to get safe distance from the head you have to throw another .040 gasket on top and have a pig of a motor or cut the step out altogether.  
Would you rather have a 9.5:1 motor with 59ccs(measured to the step) and .080 deckheight(.040 gasket required for safe clearance) or a 9.5:1 motor with 59ccs(by opening the chamber a little)and .040 deck height?  The one with the tighter deck is going to run better.  

 Yes the step cut doesn't give the ideal chamber shape, but opening it up just to get cc's often doesn't either.

Id rather open the chamber a bit then run double the deckheight I need.   Snappier engine with easier tuning and less detonation will make it worth it.

If that step was cut to allow the piston to fit inside and was 0.040 deep would you be removing it then? No because its the same as using the copper head shim you mention.

Yes if the step was cut properly I would have used it to set my deck height, which when added to the actual 55 cc chamber measurement would put me over 10:1, and I still would have had to open up the chambers

They advertise them as having 59cc's in the chamber and I am pretty sure they do if you measure it all

Yes they are 59cc if you measure up to the step but thats not how  you measure combustion chamber ccs.  Chamber ccs are only the bowl area around the valves, shown outlined in black

the flat area above and below is all quench pad, to be measured into the deck height

I thought the Los panchitos were only about $650 a pair in 94mm bore?

Ah yes sorry when I bought them they came to about $700 with shipping, i forgot I had some other things that came in with the same order.

To warn others about the step is good, but other head shops sell the same thing, lots of 043 castings come like that, I would guess CB didn't put that step in, the head came that way  

Yes, had I known.  They arent advertised as 043 castings, there is no mention of it, if you look at the Panchitos ad the casting number has even been machined off.  I guess I just assumed( I know, my fault) that they were 044s, and I thought that a head advertised as supporting 160hp out of the box wouldnt leave me running a deck height of .080, that was unexpected.  

[leec]

I am not being a smart arse, but if you were that unhappy with them why didn't you send them back for a refund?

Lee

[richie]

Matt

I guess we are just going to have to disagree on this one, but here goes anyway

1 I never quoted what deck height is, I  stated that everything is taken into account to get compression, which it does have to be, and unless you dyno back to back the same engine with and without the step, then you will never know for sure what difference it makes. I know the theory but have seen some complete turds on paper run way better than they should and some that were built with all the correct theory run like pigs I have even built a couple, the old car went 9.23@152 with over 0.100 deck

2 Everyone has there own choice of the way they want to do it, yours is in the bowl in the chamber, that's fine, others might run more deck, 0.040 is real tight for those drivers that don't have much appreciation of valve float etc   I have seen plenty of engines with around 0.040[ try actually finding copper shims that measure 0.040 exactly, but that's for another topic] that don't have any carbon build up on the piston outer area or head flat surface area due to it slightly touching at high rpm

3 Generic heads are one size fits all, reality is they don't actually fit any, you always have to do some work, or be prepared to make a compromise, but I don't get why you are complaining about it, you knew before hand that even with 59cc and your perfect 0.040 deck it would be to much compression for you so some work would be needed did you not? I am guessing the stroke in my calcs but neither 82 or 84mm would work

4 What?  so the chamber area in the head that doesn't fit your ideal shape is not the chamber? if the chamber was 0.100thou deeper but didn't have the step, it was just the shape of the "bowl" would it not be the chamber then?  I measure chamber size with a clear Perspex disc with a hole in it, it has the correct OD for 94mm bore cylinder, then use a pipette to get cc, it would show the total cc, there is no way to measure just the "bowl" area like this. It measures the total chamber area

5 and if you wanted more compression you would have to machine the chamber smaller, what's the difference? as I mentioned generic one size fits all heads rarely fit anything correctly   We both surely know enough to realise that

cheers Richie

[K-Roc]

I agree with all Ritchie is saying..... volume is volume, all of it.......

Another thing, Un shrouding valves to gain chamber volume is the worst thing you can do to a designed chamber/port.... It destroys the discharge  coefficent  and velocity , kills flow and especially torque.

A port, valve seat angles,and chamber shape all work together.  

If after you machine the step off the heads to get a flat fire deck. And you find you need more cc volume to get your desired compression, you should be mirroring the chamber shape in the top of the piston to gain the volume, not enlarging the chamber.


K-Roc.

[Matt Tobias]

Well that was lively!  Thanks everyone for your input I certainly didnt want to get in a pissing match with anyone just wanted to let people know what they were getting since there is no mention of it on CBs site.
Matt

[Red Rooster]

Well I thought I would share a few thoughts, I'm relatively new on the lounge but have been a viewer for quite some time and this thread is similar to situations I see on a weekly basis.

I work a full time job but run a machining and fabrication service in my spare time from street cars to 6 second V8's.

The bulk of work is heads for VW's and the case is normally as follows;

A guy is building an engine and he has a big pile of parts that will make a 160hp 2276. However these parts don't just go together easily. the flywheel does not run true to the crank, his deck heghts are all over the place and all different and his ready to fit CNC heads need further machine work because the chamber ends up too large once he has finished removing all the steps where the seats where fitted etc and they now need machining deeper. Add this to his balancing cost and having me check his bargain dyno time only con rods that are really 0.003" out of round and the time and cost is spiraling. his budget created out of clicking the online shopping cart has grown by another 20% already!

He is annoyed that its now costing him far more money that he expected. All of a sudden those heads built to order and spec don't seem quite as expensive now??

The reality is engine building traditionally is about all of the machining and equal matching of parts to increase performance and every engine is different. there is no off the shelf one size fits all component. There are lots of good parts that can be used to very good effect but its the additional work that goes into all of theses parts that you pay a top engine builder for and hence the reason why over say 20 engines of similar spec there is perhaps two amazing engines 8 good ones a few reasonable ones and as many shocking ones despite being built with the same parts.

We are supplied with the vast array of off the shelf parts ready to bolt on but the truth is still however there is an element of finishing needed to adapt and optimise these parts for your application. We either do this or compromise what we end up with.

cheers

David

[rick m]

All very interesting opinions....  :-)  All of the comments have some validity. What really matters is what you are trying to accomplish and how.

Build it... Tune it... Drive it!

[Jeff68]

Well I thought I would share a few thoughts, I'm relatively new on the lounge but have been a viewer for quite some time and this thread is similar to situations I see on a weekly basis.

I work a full time job but run a machining and fabrication service in my spare time from street cars to 6 second V8's.

The bulk of work is heads for VW's and the case is normally as follows;

A guy is building an engine and he has a big pile of parts that will make a 160hp 2276. However these parts don't just go together easily. the flywheel does not run true to the crank, his deck heghts are all over the place and all different and his ready to fit CNC heads need further machine work because the chamber ends up too large once he has finished removing all the steps where the seats where fitted etc and they now need machining deeper. Add this to his balancing cost and having me check his bargain dyno time only con rods that are really 0.003" out of round and the time and cost is spiraling. his budget created out of clicking the online shopping cart has grown by another 20% already!

He is annoyed that its now costing him far more money that he expected. All of a sudden those heads built to order and spec don't seem quite as expensive now??

The reality is engine building traditionally is about all of the machining and equal matching of parts to increase performance and every engine is different. there is no off the shelf one size fits all component. There are lots of good parts that can be used to very good effect but its the additional work that goes into all of theses parts that you pay a top engine builder for and hence the reason why over say 20 engines of similar spec there is perhaps two amazing engines 8 good ones a few reasonable ones and as many shocking ones despite being built with the same parts.

We are supplied with the vast array of off the shelf parts ready to bolt on but the truth is still however there is an element of finishing needed to adapt and optimise these parts for your application. We either do this or compromise what we end up with.

cheers

David

David This is the best post I've read about engine building in a long time!! There is much more to it than just buying parts in the ads! Many know this but for those new to the air cooled performance engine building world this is great information!

[Red Rooster]

Well I thought I would share a few thoughts, I'm relatively new on the lounge but have been a viewer for quite some time and this thread is similar to situations I see on a weekly basis.

I work a full time job but run a machining and fabrication service in my spare time from street cars to 6 second V8's.

The bulk of work is heads for VW's and the case is normally as follows;

A guy is building an engine and he has a big pile of parts that will make a 160hp 2276. However these parts don't just go together easily. the flywheel does not run true to the crank, his deck heghts are all over the place and all different and his ready to fit CNC heads need further machine work because the chamber ends up too large once he has finished removing all the steps where the seats where fitted etc and they now need machining deeper. Add this to his balancing cost and having me check his bargain dyno time only con rods that are really 0.003" out of round and the time and cost is spiraling. his budget created out of clicking the online shopping cart has grown by another 20% already!

He is annoyed that its now costing him far more money that he expected. All of a sudden those heads built to order and spec don't seem quite as expensive now??

The reality is engine building traditionally is about all of the machining and equal matching of parts to increase performance and every engine is different. there is no off the shelf one size fits all component. There are lots of good parts that can be used to very good effect but its the additional work that goes into all of theses parts that you pay a top engine builder for and hence the reason why over say 20 engines of similar spec there is perhaps two amazing engines 8 good ones a few reasonable ones and as many shocking ones despite being built with the same parts.

We are supplied with the vast array of off the shelf parts ready to bolt on but the truth is still however there is an element of finishing needed to adapt and optimise these parts for your application. We either do this or compromise what we end up with.

cheers

David

David This is the best post I've read about engine building in a long time!! There is much more to it than just buying parts in the ads! Many know this but for those new to the air cooled performance engine building world this is great information!

thanks Jeff.

I am certainly no expert. I build my own engines however but machine work is where I concentrate my efforts.

Its also worth noting how many people bring parts to me just to check, rods cylinders etc once you tell them over a beer about a job you have on where one rod is a little tight on bearing clearance etc and the usual response is, ah but mine are new, do I need to check them still??

I adopted a logic from a friend who works in a V8 shop, they assume everything is wrong, check it and check it again. if its right then start building!

If not get it right!

I'm not dissing parts here either, far from it but always consider a set of rods made in China, they are built to a price, the sampling procedure for them maybe to 100% inspect one in 50, 100 or even 500. Bad parts do slip through. I know this from working in the engineering industry. the only way it won't happen is if every part is given a 100% inspection before despatch. In my day job for the work we do this can add up to an additional 30% in cost which if its for the aviation industry is well spent however for crankshaft pulley way over the top.

Cheap parts are by no means bad but it pays to check everything(even top dollar stuff) before you start. if you don't have the measuring equipment either invest in some if you plan on building engines often or take your parts to a machine shop or an engine builder to check for you.

It may well be the best 100-200 pounds you ever spend if it keeps you 6k engine in one piece.

Cheers

David

[leec]

Interesting posts David.
If you were to recommend some measuring equipment to check parts, what would you suggest to buy?
Sorry for the thread hijack but figure many people could benefit from checking procedures

Lee

[Red Rooster]

Hi Lee,

And yes sorry to hijack the thread.

I can make a basic list of some basic stuff that I find invaluable.

I will see if I can post some links of tools in the UK so people can get an idea of what's needed and prices too.

David

[Catbox]

This is a photo of my Steve Timms Stage 2 head.


See the step?
Even the Timms heads have them.
It is 0.054" and I believe that my piston is in the hole somewhat from what I remember.
I will be getting the step cut to the proper size for my desired compression ratio after some fresh measuring and a the time of service my machinist will be opening the center of the step to clear my 94's.
I did not want to cut into the good looking chamber work, so I dug into the pistons to create more chamber volume with a set of valve eyebrows.
These are just some of the little things that have made my 2332 engine project take what seems like forever to get around too...

[j-dub]

My 034 based Steve Tim's stage 2 heads had the same step as well. in the end I ended up having the step filled with weld, the heads machined and the chambers touched up to get the proper volume I needed.

I think this may just be par for the course when building a custom engine.

[Zach Gomulka]

My 034 based Steve Tim's stage 2 heads had the same step as well. in the end I ended up having the step filled with weld, the heads machined and the chambers touched up to get the proper volume I needed.

I think this may just be par for the course when building a custom engine.

Could you have reached the same compression ratio if you ran zero deck in the cylinder and left the step in the head (assuming it had the proper ID)?

Is there a difference between the two; having the combustion in the deck of the iron cylinder, or the aluminium head?

[Jon]

I know what I value more, a head flowing like the porter intended with a good squish, or some magical compression number somewhere under ten.

[Torben Alstrup]

I agree with all Ritchie is saying..... volume is volume, all of it.......

Another thing, Un shrouding valves to gain chamber volume is the worst thing you can do to a designed chamber/port.... It destroys the discharge  coefficent  and velocity , kills flow and especially torque.

A port, valve seat angles,and chamber shape all work together.  

If after you machine the step off the heads to get a flat fire deck. And you find you need more cc volume to get your desired compression, you should be mirroring the chamber shape in the top of the piston to gain the volume, not enlarging the chamber.


K-Roc.

X 2
And ditto to the Rooster.

That´s some of the stuff people do not understand or will not pay attention to, because it is nowhere in the magazines, so it´s not needed. 

T

[Red Rooster]

in response to Lee here goes with a few basic things I don't think people should be without.

id say this is the bare minimum for putting a motor together safe in the knowledge its right.

I'm assuming here that everyone has access to things like feller gauges, straight edge, vernier etc.

a section of micrometers from 0 up to at least 75mm preferably 100mm. these can be bought used but don't be to worried about accuracy a most uses are using them in conjunction  with the next item on the list and your using them more for point of reference than obtaining sizes. http://www.amadeal.co.uk/acatalog/Outside_Micrometer_Sets.html

a dial bore gauge such as this http://www.machine-dro.co.uk/50-to-160mm-dial-bore-gauge.html
to suit the bore your measuring. this is the budget version of a 50 to 150mm version but sizes are available from about 18mm upwards. this is used to check how round and straight a bore is and clearances on anything from liters to rods, main bearings etc. to use you get your micrometer and measure you lifter, crank journal, or anything that runs in a bore and lock your micrometer up at that size.

them set your bore gauge to read zero when rocked between the micrometer anvil. then pop the bore gauge into your bore, be it a lifter bore, a rod with a bearing in torqued up, case halves etc and read off the gauge your clearance of your parts. compared with plastiguage its much more accurate and also it shows taper and any ovality. you can use this on anything that runs in a bore but specifically bearing clearances and lifter bore clearance, even a distributor drive can be checked this way.

also cylinders can be checked for piston clearance etc, ovality although its not accurate to check without them being torqued in place.

a set of accurate digital scales

A dial gauge and magnetic base for measuring valve lifts, and also something I doubt many people check, crank runout. for this you need a pair of vee blocks and a flat surface. a peice of granite worktop works well as a surface plate if you can't justify a proper one. place the crank in the vee blocks and check with the dial gauge the run out of the  rank when rotated in the blocks. flywheel run out can be checked in the same manner.

 http://www.rdgtools.co.uk/acatalog/Vee_Blocks_and_Clamps.html

small bore expanding gauges for  checking valve guide clearance  with micrometer

valve spring tester, cheap ones that use a vice will do

valve spring height micrometer.

burette.

these are basics that are required to confirm sizes and clearances etc when building your motor.

there are many more tools out there and what I have linked are basic budget tools, like anything you get what you pay for but for a few of your own engines they are perfect. if you plan to make a liwing from it invest in some quality kit it will last a lifetime if looked after.

also there are far more usefully tools out there that can be added to this list but these things once you have you will wonder how you ever lived without them!

apologies for the messy post, my pc is down and all this was done from. my mobile phone.

if anyone needs any measuring equipment or advice on how to use it to full effect we ha e companies we buy from I'm sure we can help you out just drop an email to northracemotorsport@yahoo.co.uk and any help I can offer your welcome to.

cheers

David