Forging 4E

E

elison

Member +
Hello Turbo Friends,

I tought its time to share some info with you. Im currently almost done with sorting parts out for my second 4E build. First one died due to wrong advice. But now after long nights of doing research and a bit of my own knowledge and the builders knowledge i decided its time for the second build. So im postin a little bit of info on the engine so you can give your input and advice on it.

-Bone stock 4EFTE to rebuild
-Ross 74.5mm Forged pistons
-SCAT HBeam Rods with ARP bolts
-Complete ACL Aluglide bearing set (Main,Rods,Thrust)
-ARP Head bolts
-1.6mm Cometic MLS Headgasket
-Toyota Overhaul Gasket Kit (all seals)
-New Timing Belt and Tensioner
-Tial 38mm External Wastegate
-T28 Turbo. (But thinking of buying a GT2860RS .63 A/R Exh Housing)
-Head remains as is (not planning to modify it)
-Speedvision double core Aluminum Radiator and fan
-Front mount intercooler (27x6x2.5)
-New dizzy rotor and cap
-440cc RX-7 Injectors
-Walbro 255 fuel pump
-AEM Fuel Pressure Regulator

-Haltech Sprint 500 stand alone ECU
-Greddy Profec E-01 Boost controller
-Stock ignition (planning on getting a MSD6A and a MSD Coil for better spark)

Also planning to skim the head and deck the block for perfect fitment of headgasket. Compression ratio would be around 8.3:1 with this setup.

Planning to to run about 1 or 1.1 bar daily and 1.6 at the track(once a month).

Your advice and knowledge and experience on this build in much appreciated.

Cheers:rockon:
 
S

Skalabala

Member +
What was the wrong advice given to you?
If you want to boost 1.6bar then you will need race fuel.
and 8.3:1 CR is a bit high for a 1.6mm gasket. The head and block will be around -0.1mm so that is like then to have 1.5mm gasket
Should be something like 8.1:1
And the pistons that you are going to use are they standard 4EFTE spec?
 
E

elison

Member +
Tnx for the info Skalabala.
They used all wrong clearance in the first one. Now im sorting things out myself so i know its good.
Im planned to use race fuel on track days to be more precise.
So you are saying that by using the ross flat tops with a 1.6mm gasket the c/r is going to be around 8.1:1?? In my opinion that would be even better if i plan to go bigger boost than now and the car wont be that sloppy to drive off boost.
Until now i will be using the ross pistons from speedvision. Thats why i posted here to get some additional thoughts and advice on the build.

What do you think about Wossner pistons? The 6cc dished ones??
Could they be used with a 1mm hg to be around the same c/r???

Cheers, :rockon:
 
weeJohn

weeJohn

Lifer
Skalabala said:
What was the wrong advice given to you?
If you want to boost 1.6bar then you will need race fuel.
and 8.3:1 CR is a bit high for a 1.6mm gasket. The head and block will be around -0.1mm so that is like then to have 1.5mm gasket
Should be something like 8.1:1
And the pistons that you are going to use are they standard 4EFTE spec?
Click to expand...

You really cant tell this until after the machining work has been done.
 
E

elison

Member +
Well, overall the engine has been taken good care of before this build. So as advised by many on the forum and also others i will skim the head and deck the block for a smooth nice and clean surface for the new head gasket. Is not like the head is bad or something that it needs to be skimmed by much so i guess it will be the bare minimum they will shave.

The only thing that im still trying to sort out before i begin the build, is a piston and headgasket combination. I got advised either Wossner 6cc dished with a 1mm head gasket or Ross flattops with a 1.6mm headgasket but i got adviced to be careful with blow by with the 1.6mm headgasket on higher boost levels (above 1.8 bar).
Some say that with the Wossner setup the c/r will be approx 7.8:1 and with the Ross setup it will be approx around stock 8.1:1

So any of your expert and well experienced advice's would be appreciated :)
 
A

AdamB

Member +
Nothing wrong with running a higher compression ratio 8.1:1, it just means that either A, you will have to run a higher octane rating fuel such as, Avgas etc or B, reduce ignition timing. This is to keep away detonation. Although the good side is that you will have a repsonsive motor, less lag, and higher power output like for like setup with only CR changing.
 
weeJohn

weeJohn

Lifer
elison said:
Is not like the head is bad or something that it needs to be skimmed by much so i guess it will be the bare minimum they will shave.
Click to expand...

They could find it off square or make a mistake, wait until its done, then measure the volumes of the head and the block with the piston at tdc, do the calculations and then buy a headgasket.
 
weeJohn

weeJohn

Lifer
Skalabala said:
And skimming changes CR by almost nothing.
Click to expand...

Bollocks, think about that, any material removed from the head or block is taking material off the combustion chamber at its greatest diameter. removing it from these areas makes the most difference, plus you can never ever tell what amount of material the machinist has remove without measuring it.
 
S

Skalabala

Member +
Changing gasket thickness is what makes the big difference. And you will in most cases remove less than 100 microns with a skim.
And a combustion chaimber is smaller than the bore. You won't even get +0.1CR if you do a 100 micron skim.
I stand by my statement :D
 
S

Skalabala

Member +
Well those heads are scrap then... If you have to remove that much material to get it flat then you will need to redo/resize combustion chambers and also line bore the cam bearings.
Done more than enough to know that a 0.1mm skim is a lot to clean/flatten
Who on earth has a 1mm skimmed standard head? You bin it if it was skimmed that much or you make a new gasket, or its for after market performance use.
 
A

AdamB

Member +
What did you CR go to John after knocking 1mm off the head? Must have shot up a fair bit depending on what gasket you used as well.
 
You must log in or register to reply here.
Top