Anyone interested in built heads? - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


Miata parts for sale/trade Buy, trade or sell your Miata parts here.

Reply
 
 
 
LinkBack Thread Tools Search this Thread
Old 01-12-2010, 11:39 PM   #1
Want fries with that?
Thread Starter
iTrader: (3)
 
Join Date: Oct 2009
Location: Twin Cities, Minnesota
Posts: 2,023
Total Cats: -1
Default Anyone interested in built heads?

I was thinking about this today.

By "built", I mean +1mm valve job, integral cams (duration/lift is up to buyer), stronger valve springs and a port and polish.

I may sound a bit of an idiot, and people will obviously want proof that I know what I'm doing and that they're worth it, I figure I can have one built by next summer to bolt on, dyno prove, and run it for a couple thousand miles to prove that it'll hold up.

Price would be around 1,400-1,500 dollars and would take about a month to build.

Given that I could prove it over the test of time and on the dyno, would anyone be interested in purchasing one?
rider384 is offline   Reply With Quote
Old 01-12-2010, 11:45 PM   #2
Senior Member
iTrader: (7)
 
Join Date: Dec 2006
Location: Chicagoland
Posts: 1,362
Total Cats: 3
Default

Seems like a good price, how much for cams alone?
jtothawhat is offline   Reply With Quote
Old 01-12-2010, 11:46 PM   #3
Elite Member
iTrader: (7)
 
Join Date: Jan 2007
Location: Renton Washington
Posts: 1,742
Total Cats: 3
Default

6 months is a long time to wait for a customer. What would be the turnaround time from deposit to ship out?
SKMetalworks is offline   Reply With Quote
Old 01-12-2010, 11:48 PM   #4
Want fries with that?
Thread Starter
iTrader: (3)
 
Join Date: Oct 2009
Location: Twin Cities, Minnesota
Posts: 2,023
Total Cats: -1
Default

Quote:
Originally Posted by SKMetalworks View Post
6 months is a long time to wait for a customer. What would be the turnaround time from deposit to ship out?
I won't be accepting orders until I know that they're proven and that they're worth making for my asking price. I'm still very early on, just planning everything out and seeing if there's a market for these.

If and when I decide to start making these it would be about a month to a month and a half, simply because the cams take 3-4 weeks to be ground.
rider384 is offline   Reply With Quote
Old 01-12-2010, 11:48 PM   #5
Want fries with that?
Thread Starter
iTrader: (3)
 
Join Date: Oct 2009
Location: Twin Cities, Minnesota
Posts: 2,023
Total Cats: -1
Default

Quote:
Originally Posted by jtothawhat View Post
Seems like a good price, how much for cams alone?
Cams are 725 a pair strait from Integral.
rider384 is offline   Reply With Quote
Old 01-13-2010, 01:15 AM   #6
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Custom cams are like $450 at www.elgincams.com
He makes you fill out a form and asks for flow numbers if you have them.
JasonC SBB is offline   Reply With Quote
Old 01-13-2010, 07:19 AM   #7
Junior Member
iTrader: (1)
 
Join Date: Apr 2008
Location: Bristol
Posts: 442
Total Cats: 0
Default

Are these regrinds or do you have to provide a blank for him to work on?
Duckie_uk is offline   Reply With Quote
Old 01-13-2010, 08:24 AM   #8
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

I'm interested, but without custom cams or +1 valves.

I simply want stronger valve springs and (possibly solid) lifters, as well as a badass port and polish...purpose being to support a slightly higher redline without power dropping off. Not shooting for the moon...just don't want power to taper off before normal redline.

EDIT: btw, this would be for a 1.6L head if it makes a difference. I recently saw the HKS 1.6 cams go for a about $350, and if it came time for cams would likely go that route before a custom grind. I don't see a huge reason to go for cams on a turbo car for my goals, and would definitely forgo it if it drastically dropped the price.
gospeed81 is offline   Reply With Quote
Old 01-13-2010, 11:30 AM   #9
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

Duckie Elgin's charge is for regrinds on stock cams so he makes the base circle smaller.
I had him do my 97 M3 with hydraulic lifters and gains were very noticeable.
I haven't asked him about what supporting mods are needed on a 99+ head (i.e. need thicker shim, does it need shim under bucket to do that).

gospeed81, the tapering off of torque is a function of the cams, less so of lack of head flow. You need a later closing intake valve - either with more duration, or by retarding the intake some.

Re: slightly higher redline - Rebello Racing tell me on a 99+ that the springs can be shimmed up a little bit to support a slightly higher redline.
JasonC SBB is offline   Reply With Quote
Old 01-13-2010, 11:36 AM   #10
meatbag
iTrader: (50)
 
gospeed81's Avatar
 
Join Date: Nov 2008
Location: Houston, TX
Posts: 7,357
Total Cats: 26
Default

Quote:
Originally Posted by JasonC SBB View Post

gospeed81, the tapering off of torque is a function of the cams, less so of lack of head flow. You need a later closing intake valve - either with more duration, or by retarding the intake some.
Forgot to mention I already have FM cam gear and plan on about 4* retard on the intake cam....but will dyno tune to perfection since I plan on a port and polish anyhow.

I've heard (recently here) that the +1 valves make less of a gain than a good P&P...and have heard elsewhere to forego cams and keep it simple on a head build. I'm hoping getting rid of the overlap will change the characteristics enough for my liking...but you know what they say about things you've heard and not researched enough.
gospeed81 is offline   Reply With Quote
Old 01-13-2010, 12:02 PM   #11
Elite Member
 
Join Date: Jul 2005
Posts: 6,454
Total Cats: 80
Default

It's not the reduction in overlap that increases torque near redline, it is the later closing intake. If you want a later closing intake without decreasing overlap, you need more duration.

Between increasing duration and simply retarding the intake, more duration is more beneficial for a high revving motor.

However because you have cam gears already you should try the retardation first. You can measure the effect without a dyno by logging AFR's on back to back street runs to high RPM on the same stretch of road, at different cam gear settings. e.g. a 4% increase in AFR at 6800 RPM pretty much means a 4% increase in torque at 6800 RPM.

On the 99+ Rebello told me +1 on the intake requires lots of extra work to make it flow. The exhaust doesn't require much work. And yes there are more gains just from the porting than +1 + porting. Dunno about the 1.6.
JasonC SBB is offline   Reply With Quote
Old 01-13-2010, 12:06 PM   #12
Junior Member
iTrader: (1)
 
Join Date: Apr 2008
Location: Bristol
Posts: 442
Total Cats: 0
Default

Quote:
Originally Posted by JasonC SBB View Post
Duckie Elgin's charge is for regrinds on stock cams so he makes the base circle smaller.
I would imagine that just changing the profile would cause minimal change in the base circle that could be compensated with a slightly thicker shim. If you wanted to go for high lift then the shim would be impractically thick and not only increase the mass of the valve train but also run the risk of flying out I expect.

Quote:
Originally Posted by JasonC SBB View Post
Re: slightly higher redline - Rebello Racing tell me on a 99+ that the springs can be shimmed up a little bit to support a slightly higher redline.
The springs from the 94-97 head are slightly stiffer than the springs from the 99+. So putting 94 springs in your 99 head with the lighter solid lifters should support a slightly higher redline. Anything more than 1k rpm and you need shim under bucket and preferably double valve springs.
Duckie_uk is offline   Reply With Quote
Old 01-13-2010, 12:16 PM   #13
Junior Member
 
Join Date: Mar 2009
Location: maine
Posts: 224
Total Cats: -1
Default

there will be a lot of interested people, you will need to come up with a list of options and prices
94blackmx5 is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 58 Yesterday 10:04 PM
Leaky Wilwoods mx592 Suspension, Brakes, Drivetrain 1 10-01-2015 01:45 AM
Bad head gasket or ? shooterschmidty Engine Performance 8 09-30-2015 11:28 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 04:30 AM.