Porting 2F heads/performance

[joka]

Howzit all,

I'm new to this forum. Live in Maui, have had 2 fj40's. Present one is a 73 with a 76 lo mileage (40K) 2f, 78 drivetrain. the whole bit, headers, weber, msd, 4" skyjacker, 33"s, mallory dist., dual batteries, 9000 warn, homemade roll cage.

Anyone ported a 2f head. I port harley heads, chevy heads, etc, but never the landcruiser. Interested in what kind of performance they've gotten doing this. I would thing it would improve top end at higher rpm's like they normally do. Never did a long stroke 6 though. Tremendous improvement with harleys and v8's. It's all about flow.

I know i won't really use it because I'm the one on the highway cruising along at 45.

 

[cruiserjunktion]

The 2f is a low rpm engine.

IMHO Porting the head for additional flow in the upper rpm range isn't worth the effort.

Post a pic of your rig...... Let us see that Maui Wow e

 

[lavarunner]

hows it from da big isle..

x2 on the not worth porting a 2f...

 

[andrewfarmer]

Disagree - well worth it

https://forum.ih8mud.com/showthread.php?t=61396

 

[cruiserjunktion]

You will have to "build" a a NEW short block to see gains from a ported head.

NOT worth effort unless you plan on building a special purpose bottom end to compensate for additional flo/ revs.

 

[grant5127]

Really it's a basic law of physics.. s*** flows more efficiently over a smooth larger surface.. giving you more flow potential..assure protection from air turbulence in your runners.. Every protruding little point in that path restricts the flow of air causing your engine to work harder both sucking in the fuel/air mixture and then pushing out spent exhaust gasses. By removing these large ridges and smoothing the flow path, you have enabled your engine to more efficiently ingest and expel air. If done correctly, this can translate into impressive HP gains..

 

[Mark W]

Mild porting helps. Don't polish it too much.

"Special purpose bottom end"?

Guess that depends what you consider Special Purpose.

A 2F built to factory spec and balance (just a static balance) will pull to 5000 just fine. Well worth a little porting at that RPM.

2F a low end motor? sure. But no reason it can't be a mid range and even moderate top end motor as well.

Hit the trail with us sometime. You'll see a few 2fs pulling hard to and above 5000 as well as lugging strong at idle.


Mark...

 

[FJ40Jim]

Like Mark said, clean up the trash around the seats, remove casting flash, polish up the chamber a little, especially on the sidewall where the intake is shrouded.

It doesn't make much difference at high RPM, IME. The cam timing makes the torque curve take a dive past 3K RPM. But, it seems to make an improvement in the useable rpm band.

I can't say what kind of difference because I've never put a "race prepped" head on an engine that was otherwise fine, so there's no apples vs apples comparison in my files.

 

[RHINO]

Really it's a basic law of physics.. s*** flows more efficiently over a smooth larger surface..

not true. too big of runner and ports will decrease velocity. for most mild builds matching gasket and removing flash is enough.

 

[desertpat]

Go 4 it!

Joka,
I support the port and polish effort as above on the intake clean-up.

On the exhaust side, I reckon there is something to be gained by enlarging and tapering the head and manifold ports to match the gasket opening, which is significantly larger.
There may also be room for improvement at the flange where exhaust ports collect.

As I said before, my friend who always brings home the trophy from the drag strip puts a lot of effort in porting.
2F's aren't racing engines, but improving efficiency has benefits.

Please post a pic of the head showing ports "before and after".

 

[cruiserjunktion]

"Please post a pic of the head showing ports "before and after".[/QUOTE]






While you are at it, do a dyno run for a baseline.

Port the head.

Do another dyno run once "PORTED".

Let us know how much time and money you spend,

and how much power you gain.



My stang has a really nice set of ported and poli$hed Brodix 2.02 heads on a steel crank 4bolt 331.

I picked up about 20hp with these heads. (dyno'd)


You MAY get 5hp+ at the tires by porting the head on a otherwise stock 2f.

You may also have alot of time and money to burn as well.

The gains don't out weigh the costs.

 

[joka]

Jim,

Thank you for responding. I've been reading about fj40's for decades and you are the man. The whole thing is that I have an extra head, have ported heads, gotten great results at the higher rpm's. Just didn't want to affect the low torque because the fj40 is a beast off the shelf.

I'll look at the mild porting to increase smooth flow.

Thanks,

John

 

[joka]

Know what you mean. It's the law of diminishing returns. The
FJ can go just about anywhere - stock, you know how it is. I've done a bunch to my FJ, performs well, thinking of other things to do, but I want to keep the stock 2F - it's a 40,000 mile motor and still registers 60 psi oil pressure. Can't trash that engine.

Thanks for the response.

John

 

[joka]

You from the Big Isle....I spend a lot of time in Kona with work and fit in some play....spearfishing. Miloli was great.......

John

 

[Pin_Head]

My experience is that it only makes a difference on engines where the ports are a significant impediment to flow. If something else is the bottleneck (valve lift, carb, intake, etc) it doesn't make much difference. It won't hurt unless you cut into the water jacket or something else inappropriate. All this experience is with Chevy SB and BB engines, so I don't know about the F/2F.