Mofoco Head Problems, Fixes, and Perfomance- Post it all here

[Nightshift]

Roy himself will need to make the decision to change what goes out the door. Machines are expensive to replace as is the tooling. Machines get old and have to be replaced. Even with proper care, lubrication and correct usage, the life span is only so long. Repairs, rebuild, finding parts and finding a good company to perform them is hard and getting harder. Let alone being without one for a month or two.
Does the machinist care or is he/she just in it for a paycheck?
Casting shifts seam to get worse over time also. Is it the casting company not paying attention to what they are doing?
Is it all the above? Any one of the above is a recipe for failure, two or three and its time to ask yourself what are going to do.

[raygreenwood]

[Ohio Tom]

[mark tucker]

yes that pushrod is dead, as is the one next to it. was it the reason or the after math....where is the spring?what rpm( true not wish/claimed rpm like idle or 11000 bs.) was the spring dead? were the keepers gaped? was the spring broken? was the raido turned up at 60 mph in first gear? did the car have front bumper....it does apear the heads still had the shit retainers...I think I put cromolys or tits on mine before they went on the engine.I was quite suprized to see those junk retainers.of coarse roy has never had any issue with them, neither have I since I wont use them. as always keep your eyes and mind wide open.

[[email protected]]

Hey everyone, I've been waiting to reply to see if anyone would post new information that hasn't either been fixed in the great cylinder head update of 2018 or been addressed by me in the past. So far, I haven't seen anything yet. This post will be like a press conference as I will not be answering any questions as they have all been answered before.

First, I appreciate ALL constructive criticism and suggestions. You are all in a very unique position of being able to give feedback to the actual manufacturer of a cylinder head and as a family business owner, I take every single word to heart. I have shown over the last 20 years of my ability to admit when I am wrong and also to update and make every single product I produce better.

That being said, here is my response to some of the things brought up in this thread. There are several pictures of failures which are all of heads that have step in the chamber, bosses in the 042/050 casting and also stock retainers on an 042. These are all things that don't apply anymore to any head I produce. This is like jumping on a forum about the new Macintosh laptops and commenting about the Mac LCII that you had back in 1992 and how the hard drive failed. One has absolutely nothing to do with the other.

So, it appears that there are two issues here that need to be addressed again. One, seat overhang. This is an issue due to the fact that my mold is a sandcast gravity mold, not a permanent injection mold. This means that the mold itself is multiple pieces and the overall head mold is the same, while the rocker box and port cores are interchangeable. The port core can shift as they are put in by hand and when they are off by .100", that is called core shift. I do not like seat overhang, I don't want seat overhang, I strive for perfection all the time. This issue will not cause any type of failure, period. I have not seen one failure in 25+ years due to this issue, you can talk theoretically all you want but I want real world facts. Next, seat overhang will only cause lower CFM on the intake and not the exhaust. IF you order any of our heads "ported and polished" we blend the seat to the port perfectly on the intake and exhaust. Some say, why don't you just fix it? Well, it's not just a flip of the switch or reprogramming. Changing a mold is very expensive and if they screw up the fix and I have to actually make new port cores, it could ruin my ability to make heads at all. I do still plan on doing it when time and money allows.

Last, the valve guide being offset. This has been addressed a few times and I understand it's a hard concept to grasp if you've never actually manufactured something. As previously mentioned, the rocker box is sand cast, which means that between the rocker box core itself and then the head being poured, there can be shortfill. When the head is bolted on to the CNC machine, the machine doesn't care where the bosses were cast, it drills the holes in the same place every time. This means that the hole for the valve guide is drilled in relation to the rocker stud hole and in relation to the other valve guide holes so the valves line up correctly. Then the spring seat is machined in relation to the hole, not the boss. Now, I have seen a couple pictures of failures and while I can't say definitely why it happened, since you know, I wasn't given a chance, the fact that it was offset would not cause any type of failure. Maybe some of you remember a very highly publicized case on here of this 'failure" After pages of accusations and bad words and general negativity, the customer bought a new set of Timm's heads......and the exact same failure occurred with those too. This customer, who I have the utmost respect for, came back on to this website, hat in hand, and admitted that it was his rocker geometry that caused both failures. He learned, he got another set of heads and he has a great running engine now.

This brings me to another point, probably the only part of this entire thread that has made me quite upset. There are a couple of you on here who keep referring to "people you know who have had these failures and are afraid to contact me." I have never refused fix a set of my heads.....never. I even fix things that I know 100% were user error. I've fixed heads that are 10 years old for free. I will lend no weight and give no thoughts to "unnamed sources" about anything. "You want answers? You want the truth? You can't handle the truth." I want names, dates, pictures and engine specs for any alleged failure and I will investigate it 100%.

And last, but not least, is this. Of all the businesses that manufacture or sell cylinder heads, I am the only one that builds engines with them every single day. I am personally the #1 customer of Mofoco cylinder heads as I have used at least 5000 heads(personally) over the last 30 years. When I started building exclusively in the early 2000's; I didn't like how the rocker assemblies sat on the 042's and 050's. I immediately halted production of our heads and went on a 6 week reprogramming of our CNC machine to realign everything. I had to learn the programming language and since our heads are machined on 3 sides(watch the video on youtube) I had to learn a lot. About 6 years ago, all of a sudden, I built 3 engines in a row that broke the tips off the valves while I was breaking it in on the stand. I immediately halted my head production until I learned it was a bad batch of Osvat valves. I communicated the problems to my supplier, they contact Osvat and Osvat recalled tens of thousands of valves. About 2 years ago, all of a sudden I built 3 engines in a row that were leaking oil between the head and the barrel. I immediately halted my head production to figure out the problem. It ended up being a problem with the CNC machine and all my heads since are finish bored on a bridgeport to insure a 100% perfect sealing surface.

Again, I thank you all for your time and efforts and if anyone has anything they wish to say or a problem for me to look at or advice, I am all ears. You can email me direct [email protected].
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Cylinder Head Reference Sheet

[Lingwendil]

[oprn]

That was a very classy and appropriate reply Roy! Hats off to a guy that cares!
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We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age)

[Lingwendil]

[calvinater]

Hello Roy, thanks for chiming in.
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"Albatross"!

[Nightshift]

Great to hear from Roy.

1 How do you explain leaky valve on new head and poor quality seat cutting?
2 I get that the spring pad/boss is cut in relation to RA stud. That being said, the boss being off is causing the springs to sit at an angle, thus causing premature guide wear? I actually had to special order spring cups to locate the springs properly for my new heads.
3 Should a customer have to do this work?

"Hey everyone, I've been waiting to reply to see if anyone would post new information that hasn't either been fixed in the great cylinder head update of 2018 or been addressed by me in the past. So far, I haven't seen anything yet. This post will be like a press conference as I will not be answering any questions as they have all been answered before."

My heads came in late 2019, Did I miss the great head update of 2018? If these were pre 2018, I would hope you would not sell them in 2019. According to your last line you wont be answering any questions. I will take that as you are satisficed with the heads you are shipping!
I will NOT be recommending, selling your products to customers or buying from Mofoco.

Good luck to you sir.

Nightshift

[[email protected]]

[Alstrup]

My 2 set puchased early 2020 I´m sure you´ll be able to find my invoice. The non TS ones were the worst.
Lee´s were early 2019.

On a positive note, I really hope it is improving. On a personal level I think I have come to the conclusion that seeing is believing.

I know enough about CNC to get myself in trouble. At least 75% of the inaccuracies with guides not being in the correct position and angle, - varying 3-3,5 degrees in the same head is almost certainly due to slack/wear in the tool holder hence my comment earlier. The last 10% can be a lot other factors. But hey, if they can do it correct in China or Brazil I´m sure its posible to do it right in the US too.

Carry on.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[chrisflstf]

[SixVolt]

I purchased a set of 040-DP (85.5/87) MOFOCO heads on May 28, 2020, Order #33652. Because I'm busy and mechanically incompetent, I didn't have a chance to install and run them before seeing this thread.
I am friends with a very competent VW tech who posts on this site regularly and I decided to run the heads over to his shop and have him give them a closer look before he reinstalls them and runs them for me.
The short answer is he saw nothing out of the ordinary in his inspection. At least nothing that would cause him to say there are obvious problems.
He disassembled the heads and checked the valves, stems, seats, guides springs retainers and clips and found nothing out of whack.
Now the proof won't come till the engine is run, but nothing visual looked out of place. He may or may not want to offer his assessment, but I'll at least show the images of him going through them. He previously air tested them and also tested the valves seating with a blueish dye today.

One last point, In the images you can see some casting numbers and there's a "1" stamped on the side of both heads. Could that be the tech who did the work?

[AlteWagen]

[Ebel]

That first spring seat would concern me. Almost 50% uncut. I’d personally want them cut 100% -75% min. The spring must bend differently without a flat seating area. It could be such a small difference it wouldn’t make a difference in longevity but I don’t know.

[modok]

Why cast the rocker box with not enough material for a spring seat?

Some engine have spring seats as deep as 1/4 down in the head. The spring is literally DEEP down in a ditch but it works fine. is that good? well, it's not bad. Maybe it is because I played with 2-strokes early on but I see excessive volume in the rocker box as just places for oil to be instead of in the sump where it should be.
So it does make you wonder why, what the point is?
Is the mofoco cnc machine not strong enough to cut deep?
Is the aluminum too costly?

If I could get a casting with enough MATERIAL to make a BIG 200hp vw engine, I'd be exited about it...because that sounds like fun.
Is that was mofoco does? no, is that what mofoco customers want, seems not.

But we seem to do this once a year anyway.... so what's new?
When I first encountered heads where the cooling fins are to shallow, I was pissed off.
When I first encountered heads where the thermostat rod won't fit through I was pissed off too.
But fixing it wasn't that hard once I actually tried and figured it out.

If having castings that need minimal machining is what mofoco customers want..... the then that's fine.
But some people have the idea that sending these castings to a miracle machinist will do wonders, well, duh, no.
I have figured out how to machine cooling fins and thermostat rod holes, but I still have not found a GOOD way to weld up valve seat and valve throat areas and spring seats. THat stuff is just really hard to do correctly. Ask anybody who isn't an idiot they will tell you the same. So there we go. And i appreciate Roy's attitude. The only way to keep this piece of HISTORY alive is PURE stubbornness, and he's got it.

I have seen mexican heads where the spring bosses APPEAR off center because the casting shifted. it just looked bad but it was not a big deal. They were some of the highest flowing heads I ever encountered. Sometimes "core shift" is how you discover good things. or sometimes how you discover bad things. Overall I've seen MORE...... COMPLAINING about needing to port the heads to match the valve seats, or clean up the cooling fins but, to me it is opportunity..... it is what I CAN fix.

If your looking for a "super accurate casting" Autolinea or china will kick your ass. So, might need to change your goals. Are people ready for that? probably not. So.....I don't know. I really don't.

[67rustavenger]

[jpaull]

[jpaull]