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I'm still running my stock 4G63 on the Evo, I decided to build a new one just to not park the Evo for such a long time.
Main use is mountains, maybe after the build sure I'll use it on tracks too, so I don't need to reach too much high power.
I need to drive it and I need it to be as more reliable as I can.
Engine is capable of 800 hp more or less, but I want to stay around 500 (600 maximum).
Torque is an important thing to look because of the main use, that's why I decide to go with a 4G64.
Already assembled the block, now we're working on the head.
Following are all the engine mods:
BLOCK
4G64 block - bore Ø 87.00
Wiseco 1400 HD forged pistons
Carrillo H-Beam L=156 forged rods CARR bolts
R-One forged crankshaft 100 mm stroke
ACL Race bearings
ARP main studs
ARP flywheel studs
ARP CA625 custom age head studs
Tomei oil slicing baffle
Tilton metallic 3-plate clutch kit
OEM oil pump / tensioner / water pump / bearings / seals / oil pan
HEAD
4G63 hand ported head: +1 intake / stock exaust
35 mm (+1) Supertech black nitride intake valves
30.5 mm (+0) Supertech exhaust inconel valves
Supertech bronze valve guides
Tomei valve springs
Tomei titanium retainers
Tomei 270° ProCam 11.5 in-ex camshafts
HKS adjustable cam pulleys
HKS timing belt
Power Enterprise head gasket
OEM lifters / rocker arms / valve locks / stem seals
Are the rods 156mm or 157mm? Hoping that's a typo as the piston won't be too happy with the compression distance for a 157mm rod.
You may want to rethink valve sizing on the head. If it's not too late, do +1 on the exhaust instead of the intake. That's what it really needs. If the intake are already done, send it back out an get +1 exhausts also.
Subscribed. Really looking forward to following this build. I've wanted to see EFR 7670 results on a properly built 2.4 for a long time.
How high do you plan on revving that engine?
I look forward to see how it works too. The 7670 is not that big, so it will be interesting how it reacts with the 2.4.
I think I will stop at 7.500 rpm, but during tuning test we will decide about it.
Are the rods 156mm or 157mm? Hoping that's a typo as the piston won't be too happy with the compression distance for a 157mm rod.
You may want to rethink valve sizing on the head. If it's not too late, do +1 on the exhaust instead of the intake. That's what it really needs. If the intake are already done, send it back out an get +1 exhausts also.
Yes, it was a typo. Rods are 156mm, thanks for the note.
Regarding the valve sizing, this was an advice from the mechanic who is building the engine.
I started the build thinking about not going over 550 hp, that's why he choose to maintain stock exhaust, he doesn't touch it below 600-650 hp.
The head is still under processing, I don't know if the seats are already done.
Nice build!
I bet the 7670 will be replaced by a 8374 w/1.45 A/R TH.
Thanks man!
I decided to start with a engine build 1 year ago, and believe me that in 1 year the ideas change some times.
I bought the 7670 because if I had waited some more weeks I would have gone with the 8374..
I tried my friend's IX with a 2.150cc + 8374. The result is a 780 hp street car, definitely too much for my use.
By the way, I don't bet with you because I think the same
Yes, it was a typo. Rods are 156mm, thanks for the note.
Regarding the valve sizing, this was an advice from the mechanic who is building the engine.
I started the build thinking about not going over 550 hp, that's why he choose to maintain stock exhaust, he doesn't touch it below 600-650 hp.
The head is still under processing, I don't know if the seats are already done.
Why do you say it would be better a +1 ex?
Thanks, Davide
Because that has what has been proven to be needed. For the power goal you stated, there isn't a need for any oversized valves...
Sean is correct, if you're going to run oversized valves, go with larger exhaust valves. There's math involved but it boils down to valve/bore ratios and your intake/exhaust ratio. If you run a massive valve on a small bore you're going to shoot yourself in the foot because the valves get so large that the air has a tough time getting around them to get into the cylinder.
Last year I ran through all the calcs for where the best improvements could be made and the stock intake size is fine for any engine using a bore smaller than 87mm. The exhaust would benefit slightly from a +1mm valve but it's not necessary. You'll gain WAAAY more with a good port job vs larger valves.
Sean is correct, if you're going to run oversized valves, go with larger exhaust valves. There's math involved but it boils down to valve/bore ratios and your intake/exhaust ratio. If you run a massive valve on a small bore you're going to shoot yourself in the foot because the valves get so large that the air has a tough time getting around them to get into the cylinder.
Last year I ran through all the calcs for where the best improvements could be made and the stock intake size is fine for any engine using a bore smaller than 87mm. The exhaust would benefit slightly from a +1mm valve but it's not necessary. You'll gain WAAAY more with a good port job vs larger valves.
excellent info!
do you happen to know if 4G63 head builders recommend enlarging the combustion chamber diameter to fit the 86.5mm bore better?
