Building the engine for 400+hp

[Dogster70]

Hey everyone, so i have a couple of questions that hopefully you all can answer for me. So [/SIZE][/FONT]im building my motor for more power i already have it sitting at 300 hp with stock internals and stock clutch, i heard a few different rumors and i need to know if they are true

Question 1, I already am seeking out the new Skunk2 alpha series rods, The GSC power division intake and exhaust valves, Skunk2 Alpha Dual valve spring and titanium retainers and i have a clutch as well. So my question is Are these upgrades alright? does anyone have any knowledge of these products and if not what are you guys recommending to me for these parts? Mind you im trying to be conservative as far as getting the best bang for my buck, meaning i have good quality items for fair prices so keep that in mind.

Question 2, As far as forged pistons im unsure of what to get seeing as theres actually a lot of options so any insight on this would be awesome!

Question 3, This is a rumor i heard and i was trying to figure out if it was true or not, I heard that when increasing power over 400 the rods dont like it very much and you are forced to tune the motor so that it lacks power in torque at low rpm or else risk throwing a rod, again insight of this would be very helpful as well.

Thank you guys so much for the replies in advance and I hope you guys have a good night!

[weederr33]

Forged rods would be a good thing for sure.

[spitfire481]

if you are going to build it I would do rods, pistons, valve springs, king main/rod bearings, head studs, oem head gaskets. We have built plenty with those parts even at over 800whp.

[Dogster70]

Thats awesome is there any recommended brands used for those items? or will any forged parts work well along with newer designed springs?

[Dogster70]

Originally Posted by spitfire481

if you are going to build it I would do rods, pistons, valve springs, king main/rod bearings, head studs, oem head gaskets. We have built plenty with those parts even at over 800whp.

Also 10:1 pistons or 9:1 pistons?

[COO86L]

Apparently I wrote a whole reply to this but it didn't send

Recipe as above is perfect. That's exactly what I'll be doing plus closed decking. I'll be running 10.5:1 CR as I can only run pump fuel. If you are building for E85 I'd leave it stock.

Skunk2 rods are good for the price but only rated to around 125/cyl so 500hp all up. Anything above that worth looking at is double the price though. Do it right, do it once.

[Dogster70]

Originally Posted by COO86L

Apparently I wrote a whole reply to this but it didn't send

Recipe as above is perfect. That's exactly what I'll be doing plus closed decking. I'll be running 10.5:1 CR as I can only run pump fuel. If you are building for E85 I'd leave it stock.

Skunk2 rods are good for the price but only rated to around 125/cyl so 500hp all up. Anything above that worth looking at is double the price though. Do it right, do it once.

awesome information man thank you!

[COO86L]

I legit had a whole write up done Oh well.

Have you built engines before? Do you have the specific tools required to do it yourself? Or are you just buying the ingredients for someone to put together?

The Skunk2 rods are very good for the price. Easy to get you out of trouble etc. but they are what they are, budget rods. For the price, I'd look at the Pauter rods or BC H beam extremes as they would be very strong and only roughly $400? more.

In saying that, a guy over here in Aus ran Skunk rods at 20 PSI on a GTX3071R from memory and made 300kW on 98 (low comp pistons) and had no issues what so ever. He had no mechanical sympathy at all and I think went through 3 sets of CV's.

My build recipe is JE 10.5:1 pistons, Argo rods (Aussie made, look them up), King bearings, ARP main and head stud, either OEM or Cometic head gaskets.
For head work I haven't really looked into it. Was mostly just going to change valve guides and probably put up rated springs in. Heads are pretty good, there's a little room for improvement but before long you'll be chasing power with wads of cash (porting and polishing).

Many reputable tuners have done all the hard yards to find the exact way not to blow these engines up. One of those techniques is limiting torque down low to save the stock rods from bending. This wouldn't be such an issue with a good set of rods though.

[extreme-86]

I was just thinking about creating a similar thread today (might still do so as my ultimate hp target is higher than the OP)

My question is, at what point does re-sleeving become a requirement ?

In general all of the following brands make top-notch products. With the pistons, the wrist pin thickness is the power handling determining factor.

We've had great success with CP on our turbo Honda builds just by using upgraded pins.

- Pistons - JE/Manley/CP (10:1 is the most common)
- Rods - Brian Crower/Manley/Pauter (these are for over 500whp as mentioned above)
- ARP Headstuds
- ARP Mainstuds/Dynosty case studs

[denso]

Im going to build an fa20 soon. The goal is around 600-650ps (550-600whp).

parts are (already arrived):

- JE pistons 10,5:1
- Manley Turbo Tuff Rods
- King/ACL Bearings
- ARP fasteners head and block
- valvesprings and retainers
- cometic headgaskets
- GTX3076
...


The customer already build the auto.trans. - we will se what it can handle.

[Jaden]

Originally Posted by denso

Im going to build an fa20 soon. The goal is around 600-650ps (550-600whp).

parts are (already arrived):

- JE pistons 10,5:1
- Manley Turbo Tuff Rods
- King/ACL Bearings
- ARP fasteners head and block
- valvesprings and retainers
- cometic headgaskets
- GTX3076
...


The customer already build the auto.trans. - we will se what it can handle.

What did he do to the trans besides a cooler?

[extreme-86]

Originally Posted by denso

Im going to build an fa20 soon. The goal is around 600-650ps (550-600whp).

parts are (already arrived):

- JE pistons 10,5:1
- Manley Turbo Tuff Rods
- King/ACL Bearings
- ARP fasteners head and block
- valvesprings and retainers
- cometic headgaskets
- GTX3076
...


The customer already build the auto.trans. - we will se what it can handle.

Keep us updated on the progress, I suspect you'll run out of turbine flow at ~550whp as the GT30 turbine flow capacity is the limiting factor on that series regardless of the claimed compressor flow.

[spitfire481]

I had a sleeved block making 700whp at only 28psi. the oil pump gear broke on a test pass at the track before we could turn it up all the way. we have a customer making 820whp on factory sleeves with no issues yet, but hes building a closed deck block and we are going for more currently.

[BRZoomTX]

Mine is still in progress, but we're using manley turbo tuff rods, JE 10.5 pistons, ACL race rod bearings, ARP head and main studs, GSC beehive valvesprings, and OEM gaskets.

I blew my stock block at 470whp. We're mixed between a rod giving out from the stress, or a potential rocker failure. Can't confirm either way at that power but it did lean more towards the rocker, as the other 3 rods didn't look too stressed yet.

The stock rods are definitely a weak point. That's why you see so many supercharger kits eating rods (low end torque hurts them as you assumed). Upgrade them if you want 400+ reliably.