16 replies to this topic

[tkal]

So the other day I was doing some thinking and my fingers got to duckduckgo and I found https://dsportmag.co...ad-development/

I wonder if we might might get a late morsel of goodness.

[TexasQuest]

Very interesting read.

[scott87star]

Was there ever a part 2?

[psu_Crash]

Interesting article!
And someone else reminding us that our heads suck

[obsolete]

I read this a while ago and looked around for part 2, but never found it. Maybe it was only in the physical magazine, not online?
Their solution to improve the ports on an old head that was designed without CFD modeling, is to make them look like the ports on modern heads, which were designed with CFD modeling. Go figure.

[jinx]

what are you not able to accomplish with the G54 head, that the stock can't ?
I don't recall the G54 cyl head actually ever having a 'flow' problem.

1st import in the 7s ?
4cylFury on stock head
EIP blue street car, stock head, stock cam 11.2, then 10.6 spraying a 75 shot at launch
Rank red car 721hp, 556tq severly bottle-necked by moded stock exhaust manifold

Quality camshaft developement always seem to be the prob, from my observation
Even if u get some magical head or even a dohc one...... there will still be the same cam problem, so.......

[tux]

dohc wouldn't have the same cam problem, it will introduce 2 new cam problems.

[Funky Phil]

Nice

[tkal]

I have not found a part 2.

As stated in the article the problem does not show on the flow bench and though I am not familiar with those specific builds I seem to remember most people having problems getting north of 350 hp, most with more torque than hp (torque wins races...blah blah).

Regardless of the outcome it is fun to see people still thinking about our humble engine.

Also if a new head were designed it seems like cam options would open up (solved), just select a cam from another engine with fresh blanks to grind, maybe an adapter for timing chain sprocket.

[jinx]

Quote

I am not familiar with those specific builds I seem to remember most people having problems getting north of 350 hp, most with more torque than hp (torque wins races...blah blah).

'Most people' probably not even setting a goal. Most run td05 & TBI
Is the hotside choking ? Cam ground correct and in sync ? Valvesprings killing power and rpm ?

Post above yours, street car 500+hp/500+tq.... same 'crappy' head. An example of when you put in the effort.
They can consult him, or reference other 350+hp builds like their target

One clubmember actaually measured a popular schnieder cam (who does that?) and discovered the grind was off
Made schnider 'get it right'. Result was almost a 100hp gain. Even if a 'happy' dyno, the difference was a tremendous
New head wont get you that, or fix that cam problem

I posted a old stock 2.0 DSM, stock cam, stock head... rev 8600rpm & hit 600hp
A stock head, stock cam 1.6 miata, rev 8800rpm, 547hp. Single item both of em changed was valvesprings

A few got the G54 to rip..... with the same crappy head. They've cracked the code by sweating the details imo

[Jonathan]

That is my old Starion (automatic) It was white and had the 14G upgrade from the factory. Had the sale sheet for it. He got it for his girlfriend as her project car. They are doing some good work to it. He is a really nice guy, the owner of DSport.

Edited by Jonathan, 25 February 2021 - 03:59 PM.

[louswheel]

psu_Crash, on 23 February 2021 - 12:33 PM, said:

Interesting article!
And someone else reminding us that our heads suck

Yeah, we got sucky head!    It's too bad no one ever really invested in duplicating that nice DOHC HKS head.  Would have made the G54 bullet proof!

[markhansenconquest]

Got lucky  2 years back and found a AMC marnel head on e bay for 150 shipped with no cam   ....It came from ACURA in ohio ....when it showed up it was a TEP  AMC MARNEL (NJV) head Over sized SS valves with  550 BUCK  port and polish  !!!!! :owent and had it tested as soon as i got it So 50 to pressure test and check flatness....
.
....I looked on TEP it cost like 1800-1900 with a stock cam and they dont use AMC now they use a M26 )..Ok back to the subject ,, when chrysler joined in they cast there own head to save money......( bad idea cheap alum with impuritys thats why they break pressure runs to impuritys and flashing spots thats why racers grind off the flashing on there trans to make those flaws go away ...   Pressure runs to flashing and impurtys and the heat stays there like a heat sink.. When U solider in new parts on a electric board and removes the heat to save the new part from burning up..Since the heat runs to the flaws in your stock manifold they grind them off ,,so the heat can flow to the heat sink exhaust gasket thats why there made out of 3 pieces of sheet metal to remove heat from manifold....!!! and take up the pressure off the expanding  alum that breaks your exhaust bolts......
) ......I have a chysler head ,,a carvan head  (over sized cam bearings to support the smog pump bolted on back side of cam ) and a AMC MARNEL ...IM a tool and die maker since i was 18  .. ( 40 years )..U can see the diffrence in the casting ..The AMC MARNEL head has nice ad sharp water ports with very little flash and the grade of alum is good alum not like the aftermarket ones ...i heard good things about the M26 head ,but i would grind all the flashing off the water ports to get MAX  antifreeze flow.........If u want to make a good head U need to start with good ALUM like 6061  T6  aircraft alum and machine it from a solid block not a casting....even the JVE is no good ,,because the metal the bolt is made out of expands more that alum when heated ....If U over heat your head u need to make sure the exhaust flange didn t warp...The best thing to do with after market head is to tap the  m6 bolts to  standard  3/8 - 16 ..when the bolt is stripped u take a 5/16 .3125 drill and drill 1/8 0r .125 deeper on exhaust bolt holes and tap 3/8 -16 and bottom tap it to fit the bigger 3/8/16 to fit and use 1.750 set screws made out of 4130 chromoly metal.........Open up all exhaust holes up to 1/32 over 3/8 to allow it to move with out breaking bolts.....when the bolt is stripped out the hole is .310 a 3/8 - 16 thread tap drill is .3125    .0025 bigger its the next bigger size to go to because its so close to .3125...U cant make some thing better than the metal it was made out of ???  if u can get a marnel njv head.........I watched a show call forged in fire and they let contestents make a blade and they dont even tell U what kind of metal they use..........what a JOKE  lets make it out of a old cresent wrinch !!!!  METAL IS EVERYTHING  just like the right kind of oil...........

Edited by markhansenconquest, 26 February 2021 - 04:46 AM.

[jinx]

common to see tech heads get all wrapped up in the technical mumbo jumbo, with total disrergard for actual performance
Where the rubber meets the road is what matters imo. Seen anyone drive a flow bench lately ?
You want a quick entertaining ride or prefer to get off writing a useless techno-babble paper ?

Praise the 4G63 as mitsu best ever, in contrast to mitsus G54 flop. Horse5hit
They run very close oem 1/4 mile times. 54 the 1st 4cyl in the 7s, 4G63 1st in the 6s. Both look great to me

Several full street 54s gone 12s on TBI/stock ecu, stock head, stock bottom end. A couple still on stock cam
The article should start off by explaining how bad those 54 struggle to perform

[Jonathan]

Would have paid top dollar if they made them.

[obsolete]

Man, this thread has it all. We've got people posting pictures of the HKS DOHC head and jinx insisting that there's nothing wrong with the G54B because some people have gone fast at the drag strip with it.
Don't ever change, SQC.

[tux]

Shame these cars aren't very plentiful or popular.  Cant imagine that these days manufacturing a dohc head at scale would be super expensive