Nonsense Thread

[agent]

There are still some things to iron out post-upgrade, but we're getting there.

[CMBusch]

The biggest thing was moving the head machining in house. We had a race car in Finland about 4 years ago who flow tested the head after he got it, and it didn't match the numbers here. Couldn't figure it out at first, then realized it was the valve jobs being done at the local machine shop. We did all the flow research and bought the seat cutters to suit. Never thought anything of it since the cutters for the local's Serdi machine cut all the angles in one short. So, we did a little experiment and ported a head, flow tested it before and after bringing it to the machinist - it had lost significant flow. Now I use a machine that cuts each angle, one at a time which is a bit more labor intensive than a single pass on a Serdi, but as the old saying goes "The machine is only as good as the operator." Another big one was getting the perfect squish on the angular part of the m20 pistons/885 heads. Milling the head, torquing it down, measuring squish, then pulling it back off to get the perfect number. The m20 really likes .037-.039" of space between the head and piston. Then little details like weight matching all the components to within tenths of grams, double/triple checking clearances, polishing bearing surfaces etc. I guess in a nutshell, QC has been the biggest factor - stopped subletting out as much work as possible. There's a huge difference between caring and someone who operates a machine for a paycheck.

That's good to know. I appreciate you going through the details with me. I assume this is referring to various M20s you've built? I guess the TL;DR version would be, "Do it yourself if you want it done right." I guess overall design and QC is what separates the good form the bad.

[ForcedFirebird]

That's good to know. I appreciate you going through the details with me. I assume this is referring to various M20s you've built? I guess the TL;DR version would be, "Do it yourself if you want it done right." I guess overall design and QC is what separates the good form the bad.

Yes and no. I try something, dyno it, try something else, dyno it, and over time it just started figuring it out. I bought my flow bench when I rented my fist little shop bay in 07 or 08, but was specializing in GM v6 engines. A lot of those skills were transferable to the m20 bottom ends - but the m20 design has it quirks that are unlike typical domestic engines (semi hemispherical chambers, angular squish pistons etc). That's why I wince when someone says they have a "ported head" without flow bench or data to back it up - every "ported" m20 head I have stuck on the bench is worse than a hand selected stock head, and far worse than my heads that only have my custom valve job. I flow them before doing any work on them and set the top ones aside for the Spec guys and/or rule limited classes. It's not just m20's, I've built very potent s50/2's, and just wrapped an m30 (actually it's an m90, but same architecture) that will go to the dyno soon.

It's a far cry from back when I stuck an 885 on my personal eta and was disappointed at the 135whp number lol. Now my Spec-legal b25 engines have to have restrictor plates to meet the 162whp cap (basically stock rebuilds with .5mm over stock pistons), and the personal best b25 makes over 200whp (I have dyno'd several very stock s50/2's and they make about 215 on avg).

The NOS Euro pistons shipped today. Pretty excited to get them. Curious to see what I can do with no class rules, only stroking to 2.8l, no fancy roller cam or anything like that, will run on pump gas at 10.3:1, and leave the stock manifold/TB for now, might do +1mm intake valves only. Don't have the spare coin to drop on ITB's just for personal enjoyment right now, but we will see what happens. I still have my shell sitting in the back of the shop covered and untouched since Apr '16 :/

[LowR3V'in]

dumb question do you use oversized valves in your heads and is that something someone should get for a
non ported head or not really.
Just an unported head with a cam does +1mm make a big difference?

[ForcedFirebird]

Not a dumb question, at all. Yes oversized valves help a non ported head - BUT - the valve job has to be done correctly. I found the just increasing the diameter of the sealing seat angle and installing the larger valve actually hurts flow because it messes with the short side radius (more than likely what you will get at a local machine shop). They need a different third angle, or have a 4th added.

[CMBusch]

Yes and no. I try something, dyno it, try something else, dyno it, and over time it just started figuring it out. I bought my flow bench when I rented my fist little shop bay in 07 or 08, but was specializing in GM v6 engines. A lot of those skills were transferable to the m20 bottom ends - but the m20 design has it quirks that are unlike typical domestic engines (semi hemispherical chambers, angular squish pistons etc). That's why I wince when someone says they have a "ported head" without flow bench or data to back it up - every "ported" m20 head I have stuck on the bench is worse than a hand selected stock head, and far worse than my heads that only have my custom valve job. I flow them before doing any work on them and set the top ones aside for the Spec guys and/or rule limited classes. It's not just m20's, I've built very potent s50/2's, and just wrapped an m30 (actually it's an m90, but same architecture) that will go to the dyno soon.

It's a far cry from back when I stuck an 885 on my personal eta and was disappointed at the 135whp number lol. Now my Spec-legal b25 engines have to have restrictor plates to meet the 162whp cap (basically stock rebuilds with .5mm over stock pistons), and the personal best b25 makes over 200whp (I have dyno'd several very stock s50/2's and they make about 215 on avg).

The NOS Euro pistons shipped today. Pretty excited to get them. Curious to see what I can do with no class rules, only stroking to 2.8l, no fancy roller cam or anything like that, will run on pump gas at 10.3:1, and leave the stock manifold/TB for now, might do +1mm intake valves only. Don't have the spare coin to drop on ITB's just for personal enjoyment right now, but we will see what happens. I still have my shell sitting in the back of the shop covered and untouched since Apr '16 :/

I gotcha. Thank you for sharing this info! I know some engine builders try to keep everything a secret so I really appreciate this.

Each platform has its own quirks for sure (i.e. how they respond to different modifications). I know that the 24V engines really don't need porting but for some reason I still see people do it... correct me if I'm wrong.

Would you say that getting a flow bench was integral to building better/higher performing engines?

I recently got my 2.8 M50 stroker dyno tuned and it made 213whp on a mustang dyno at Kassel Performance. I'm happy with the results but I feel there is much more to learn (obviously) and the engine would've made more power if I had been that scientific about it.

[ForcedFirebird]

Some stuff I don't mind sharing publicly, it's the stuff like valve angles/shapes/porting practices that cost me hours and hours of flow testing that won't be posted, you have to buy a head to see that stuff :p

That's a healthy m50 if you are using the stock cams! I rebuilt and s50 a few months ago, just +1 intake valves, +1 point compression .5mm over pistons, stock s50 cams, ebay headers, true dual exhaust and tuned x-pipe, it put down 255hp/248tq. OBD1 and wrote a chip on the dyno. He blew it up shortly after, we put a stock s52 long block in to get back to racing and it dropped to 238whp.

The 24v heads can use port work, but not with conventional thinking, just like the m20. They are even easier to screw up.

The bench helps a lot as tool, but it's not an end-all-be-all, just like the dyno. Where it really matters is when I get to go around an e36 328 on the banking at Daytona in an m20 e30 heh.

[mrsleeve]

Gots a question. Now that I am laid up for 6-8 weeks of non weight bearing and trapped at the house with a "fixed" knee...... Anyone every build a Desiccant dryer for their shop air set up??? Looking for ideas for something I can sit at the bench and tinker with so I dont feel so useless. would like to have something that will have a safe working pressure of 200ish psi as I will be upgrading my compressor in the near future as well and will havea primary per-regulator main system delivery of 175psi and would like to install all conditioning equipment on the tank side of the primary regulator and final post-regulator filtration.

Have some ideas on how to go about it, but nothing will have a decent sight glass to monitor media condition and I dont want to have to disassemble all the time to just check on media saturation levels.

[ForcedFirebird]

Wish I could hep you there. I find a lot of good ideas on YouTube University.

Sometimes my job has some awesome perks. Might not be getting rich doing this stuff, but get opportunities of a lifetime. One of the local Exotic car clubs (Dream Drive Exotics) called me today and need me to come out to the track and coach some drivers, or take their friends for ride-along. So, I am going to get paid to go to the track and coach/drive some really neat cars...

https://dreamdriveexotics.com/cars/

[LowR3V'in]

I found the just increasing the diameter of the sealing seat angle and installing the larger valve actually hurts flow because it messes with the short side radius (more than likely what you will get at a local machine shop). They need a different third angle, or have a 4th added.

The machine shop i go to says they do a 3 angle grind on all heads.
is that what u mean? just wondering if the +1mm could be a huge difference say on a boosted m30.
don't see anyone really doing that. more like one of the last mods you want to do type of thing.

[ForcedFirebird]

Your local machine shop is the epitome of NOT what to do. :p

[ForcedFirebird]

Valve angle is the most important part of a high performing cylinder head. Sorry bro, IIWIS

[CMBusch]

Some stuff I don't mind sharing publicly, it's the stuff like valve angles/shapes/porting practices that cost me hours and hours of flow testing that won't be posted, you have to buy a head to see that stuff :p

That's a healthy m50 if you are using the stock cams! I rebuilt and s50 a few months ago, just +1 intake valves, +1 point compression .5mm over pistons, stock s50 cams, ebay headers, true dual exhaust and tuned x-pipe, it put down 255hp/248tq. OBD1 and wrote a chip on the dyno. He blew it up shortly after, we put a stock s52 long block in to get back to racing and it dropped to 238whp.

The 24v heads can use port work, but not with conventional thinking, just like the m20. They are even easier to screw up.

The bench helps a lot as tool, but it's not an end-all-be-all, just like the dyno. Where it really matters is when I get to go around an e36 328 on the banking at Daytona in an m20 e30 heh.

Oh, yeah I probably should've specified. It's a 2.8l with 11:1 compression (M52 crank and rods, keeping the M50 vanos pistons) and S52 cams. So probably not as impressive, but I was still pumped with those numbers for never having rebuilt an engine before. The fact that it's still running a year after I fired it up for the first time is huge for me.

Damn, do you know why it blew up? i.e. user error or mechanical error?

Ahh understood. I was always under the impression that they flowed plenty, even for F.I. applications.

Haha right. None of these tools is going to be the answer, but a combination of them will be pretty close.

That's awesome that you get paid to blast around the track in those cars. They're probably the best billable hours to date.

[LowR3V'in]

so basically every head rebuild place does a sorta crappy job.
do you think valve lapping should be done or na?

[ThatOneEuroE30]

Added a new family member. His name is koah. He’s a siberian husky

[roguetoaster]

Got him from Blunttech, did you? I mean, look at his forehead.