???? Sr20det head ???? - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Dj Ryderz · 03-13-2009, 10:05 PM

So I have a few question for my sr20det.

I am going to built my block and my head. I wanted to buy Brian Crowers Valves (std size) but its seem to be discontinuated . Then I ask my guy who makes my head if that disturbs if I put valves 0.5mm oversize. He Said that it could be touch together or even touch the piston etc etc..... Is that true or it would be fine ???

My second question is if I have a bore of 86.5mm, is this ok if I put a 87mm headgasket.

Finally if it can help, heres my setup.....

-Solid 260 12mm lift intake cam
-Solid 270 12.5mm lift exhaust cam
-BC springs & retainers
-Cp Piston 86.5mm at stock compression.

Thx guys

aNskY · 03-14-2009, 09:15 AM

-well it sounds like your "guy who makes your head" isn't very knowlegable... oversize valves are oversize in diameter, not height... thus allowing more CFM's to flow through your head. they require (expensive) machining, and even more expensive machining to make them worth while..

-all sr HG's are 87mm bore unless you specify bigger , so yes you are fine using that.

-those cams are really high lift, you better check your clearance before you put it together... depending on who milled your block and head and how much, you may have interference issues

smelly240 · 03-14-2009, 09:32 AM

i mean its possible that they could theoretically his the piston since they're on a slight angle... but they'd have to be a LOT oversized.... .5 mm arent gonna be a problem.

your "guy" fails

and who said they're discontinued??? i got a set in stock size a few weeks ago

http://enjukuracing.com/brian-crower...ml?cPath=24_78

Dj Ryderz · 03-14-2009, 01:06 PM

-frsport.com told me they are discontinued.
So I'm gonna try Enjuku this week.

Thx for the clarification.

Zerolift Autolab · 03-14-2009, 04:25 PM

Unless you have an issue with your Current Stock valves i would not replace them.
The OE valves are sodium enriched and are just fine for nearly all purposes.
I would suggest that you go with Supertech Valvetrain and for sure
throw a set of rods in that motor while its all torn apart.
PM Sent - Thanks

Dj Ryderz · 03-15-2009, 01:32 PM

I don't have any issue with my stock valve but my head has 170 000km on it so......
For the rod, I allready have Eagle.

Thx for the info.

03-13-2009, 10:05 PM	#1
Dj Ryderz Join Date: Jul 2008 Location: Canada Age: 33 Posts: 40 Trader Rating: (0) Feedback Score: 0 reviews	???? Sr20det head ???? So I have a few question for my sr20det. I am going to built my block and my head. I wanted to buy Brian Crowers Valves (std size) but its seem to be discontinuated . Then I ask my guy who makes my head if that disturbs if I put valves 0.5mm oversize. He Said that it could be touch together or even touch the piston etc etc..... Is that true or it would be fine ??? My second question is if I have a bore of 86.5mm, is this ok if I put a 87mm headgasket. Finally if it can help, heres my setup..... -Solid 260 12mm lift intake cam -Solid 270 12.5mm lift exhaust cam -BC springs & retainers -Cp Piston 86.5mm at stock compression. Thx guys

03-14-2009, 09:32 AM	#3
smelly240 Nissanaholic! Join Date: Oct 2006 Location: Philaburbia Age: 43 Posts: 2,137 Trader Rating: (4) Feedback Score: 4 reviews	i mean its possible that they could theoretically his the piston since they're on a slight angle... but they'd have to be a LOT oversized.... .5 mm arent gonna be a problem. your "guy" fails and who said they're discontinued??? i got a set in stock size a few weeks ago http://enjukuracing.com/brian-crower...ml?cPath=24_78 __________________ HREs on a S13 - check, 6262 - check, Girlfriend.... - nope

03-14-2009, 04:25 PM	#5
Zerolift Autolab Post Whore! Join Date: Jan 2008 Location: Fairfield, OH 45014 Age: 38 Posts: 2,804 Trader Rating: (12) Feedback Score: 12 reviews	Unless you have an issue with your Current Stock valves i would not replace them. The OE valves are sodium enriched and are just fine for nearly all purposes. I would suggest that you go with Supertech Valvetrain and for sure throw a set of rods in that motor while its all torn apart. PM Sent - Thanks __________________ Contact: Phone - 513-874-2508 AIM - ZLR0bert Email - [email protected] Zerolift facebook - http://www.facebook.com/Zerolift

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03-14-2009, 09:15 AM	#2
aNskY Nissanaholic! Join Date: Apr 2005 Location: NY Age: 37 Posts: 1,604 Trader Rating: (10) Feedback Score: 10 reviews	-well it sounds like your "guy who makes your head" isn't very knowlegable... oversize valves are oversize in diameter, not height... thus allowing more CFM's to flow through your head. they require (expensive) machining, and even more expensive machining to make them worth while.. -all sr HG's are 87mm bore unless you specify bigger , so yes you are fine using that. -those cams are really high lift, you better check your clearance before you put it together... depending on who milled your block and head and how much, you may have interference issues

03-14-2009, 01:06 PM	#4
Dj Ryderz Join Date: Jul 2008 Location: Canada Age: 33 Posts: 40 Trader Rating: (0) Feedback Score: 0 reviews	-frsport.com told me they are discontinued. So I'm gonna try Enjuku this week. Thx for the clarification.

03-15-2009, 01:32 PM	#6
Dj Ryderz Join Date: Jul 2008 Location: Canada Age: 33 Posts: 40 Trader Rating: (0) Feedback Score: 0 reviews	I don't have any issue with my stock valve but my head has 170 000km on it so...... For the rod, I allready have Eagle. Thx for the info.