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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?
Aug 17, 2018, 04:57 AM
