KA-T Questions - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

calebbo · 02-04-2018, 12:32 PM

The goal is 220WHP

This is what I bought:
Turbo, Elbow, Coolant lines (Rebuilt SR T25)
Turbo Manifold (ISR V2)
FMIC Kit(CX Racing)
3" Exhaust (HKS Hi Power)
550cc Injectors (Deatschwerks)
Enthalpy Tune
Z32 Maf (N62)
BOV (HKS)
Headgasket (Felpro)
ARP Head Studs
Spark Plugs
Oil Feed/Oil Drain Lines
Glow Shift Gauges (Boost, Water Temp, Oil Pressure, Wideband)

Timing Chain Kit Install by shop (Includes *)
* Front Main Seal
* Tapped Oil Pan
* Oil Pump

My question is pertaining to the head.

When I swap out my head studs to ARP and change the gasket to a felpro, should I go ahead and swap out the valve stem seals?

I also have 200PSI compression on all 4 cylinders on a warm engine. Wide open throttle. 4 engine cranks. MATCO compression tester.

I assume this is carbon buildup since max is supposed to be 179-180PSI. So should I set the pistons to TDC and scrape off the carbon on the pistons while the head is off?

tuzzio · 02-05-2018, 08:08 AM

If you're already doing all this work, I would absolutely change the head studs and head gasket.

calebbo · 02-05-2018, 08:28 AM

Quote:

Originally Posted by tuzzio

If you're already doing all this work, I would absolutely change the head studs and head gasket.

The HG and head studs are a given. I just don't know if I should swap the valve stem seals and scrape off the carbon on the pistons.

EnnEssEnnKAT · 02-05-2018, 08:46 AM

Valve stem seals have a spring built into them so they wear and tear and get weaker over time. Prob a good idea if you have the spring compressor to remove and replace them with new.

Sent from mTalk

calebbo · 02-05-2018, 08:48 AM

Quote:

Originally Posted by EnnEssEnnKAT

Valve stem seals have a spring built into them so they wear and tear and get weaker over time. Prob a good idea if you have the spring compressor to remove and replace them with new.

Sent from mTalk

Do the valves need to be replaced as well or are they fine?

I have low HP goals. Around 220 at the wheels.

The warm engine compression test showed 200psi on all four cylinders after 4 cranks. It seems to be a very healthy engine. It has ~90k miles on it.

EnnEssEnnKAT · 02-05-2018, 09:35 AM

Quote:

Originally Posted by calebbo

Do the valves need to be replaced as well or are they fine?

I have low HP goals. Around 220 at the wheels.

The warm engine compression test showed 200psi on all four cylinders after 4 cranks. It seems to be a very healthy engine. It has ~90k miles on it.

It seems to be pretty high compression for a used motor. As for the valves those do not need to be replaced, they're typically reused. What I've done is remove them and soak them in a special detergent to remove the carbon deposits and then reassemble. That's the best 'free' option.

Sent from mTalk

calebbo · 02-05-2018, 11:36 AM

Quote:

Originally Posted by EnnEssEnnKAT

It seems to be pretty high compression for a used motor. As for the valves those do not need to be replaced, they're typically reused. What I've done is remove them and soak them in a special detergent to remove the carbon deposits and then reassemble. That's the best 'free' option.

Sent from mTalk

That's why I assumed it was carbon build up.

Anything I should do besides replace the seals? How a bout scraping off the carbon from the tops of the piston? Will that help lower the compression test to 180?

tuzzio · 02-05-2018, 10:02 AM

Valve seals are so cheap youd be a fool not too.

jwt makes a tool where you dont have to remove the head. works well.

calebbo · 02-05-2018, 11:37 AM

Quote:

Originally Posted by tuzzio

Valve seals are so cheap youd be a fool not too.

jwt makes a tool where you dont have to remove the head. works well.

Well a fool I will not be. Replacing them.

02-04-2018, 12:32 PM	#1
calebbo Leaky Injector Join Date: May 2012 Location: Fort Worth, TX Posts: 113 Trader Rating: (1) Feedback Score: 1 reviews	KA-T Questions The goal is 220WHP This is what I bought: Turbo, Elbow, Coolant lines (Rebuilt SR T25) Turbo Manifold (ISR V2) FMIC Kit(CX Racing) 3" Exhaust (HKS Hi Power) 550cc Injectors (Deatschwerks) Enthalpy Tune Z32 Maf (N62) BOV (HKS) Headgasket (Felpro) ARP Head Studs Spark Plugs Oil Feed/Oil Drain Lines Glow Shift Gauges (Boost, Water Temp, Oil Pressure, Wideband) Timing Chain Kit Install by shop (Includes ) Front Main Seal * Tapped Oil Pan * Oil Pump My question is pertaining to the head. When I swap out my head studs to ARP and change the gasket to a felpro, should I go ahead and swap out the valve stem seals? I also have 200PSI compression on all 4 cylinders on a warm engine. Wide open throttle. 4 engine cranks. MATCO compression tester. I assume this is carbon buildup since max is supposed to be 179-180PSI. So should I set the pistons to TDC and scrape off the carbon on the pistons while the head is off? __________________ 1991 S13 w/ rebuilt KA and Trans

Thread Tools
Show Printable Version Email this Page
Display Modes
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode

02-05-2018, 08:08 AM	#2
tuzzio Nissanaholic! Join Date: Oct 2013 Location: Western Mass. Posts: 2,254 Trader Rating: (3) Feedback Score: 3 reviews	If you're already doing all this work, I would absolutely change the head studs and head gasket.

02-05-2018, 08:46 AM	#4
EnnEssEnnKAT Zilvia Junkie Join Date: Sep 2014 Location: New Hampshire Posts: 427 Trader Rating: (13) Feedback Score: 13 reviews	Valve stem seals have a spring built into them so they wear and tear and get weaker over time. Prob a good idea if you have the spring compressor to remove and replace them with new. Sent from mTalk

02-05-2018, 10:02 AM	#8
tuzzio Nissanaholic! Join Date: Oct 2013 Location: Western Mass. Posts: 2,254 Trader Rating: (3) Feedback Score: 3 reviews	Valve seals are so cheap youd be a fool not too. jwt makes a tool where you dont have to remove the head. works well.