GermanLook Forums  

Go Back   GermanLook Forums > Technical Section > Engines

Reply
 
Thread Tools Display Modes
  #1  
Old August 14th 2002, 10:47
samcat's Avatar
samcat samcat is offline
Registered User
 
Join Date: Aug 2002
Location: Bristol, UK
Posts: 395
Question What heads/headwork should I get?

Hi everyone.

Have been thinking about replacing the stock heads on my engine. As you can see its already had a fair bit of work done

Tell me what you think/reccomend for heads/headwork (valve sizes etc) and WHY. I like to know the reason for peoples choices/suggestions.

The car is driven every day, and needs to be able to potter along at low speed as well as blasting around like a nutter :silly:

-------------------- Engine spec --------------------

Stock 2-litre crank and rods. Crank balanced with 914 flywheel and clutch. Flywheel

lightened.
Rods balanced end to end and with each other.
Rods rebushed.
New Mahle 94mm barrels and pistons, pistons balanced in weight to each other.
Eurorace E-grind cam (280o Duration 435" Lift ) with hydraulic followers.
Bolt together rocker gear.
Stock oil pump.
Case machined by JMR along with the Porsche fan.
Stock T25 heads rebuilt with new guides valves.
BAS 911 fan fitting kit.
BAS oil filler tube.
BAS Carb linkage.
Mallory Unilite optical with Vaccum advance (10o Initial, 24o Max centrifugal, pair of grey springs, Vaccum NOT connected yet.).

911 bottom pulley.
GT Mouldings fanshroud.

LA Performance J tubes and merge, custom made full flow stainless silencer system after the

single triangular flange.

Weber 40 IDF's with 32mm chokes. - SOON TO BE DELLORTO DRLA 40's.

MSD 6AL ignition system, rev limiter set at 6000rpm.
MSD Blaster 2 coil (with MSD coil bracket).
MOROSO BLue Max ignition leads, tailor made to the exact correct lengths.

Gearbox is a 911/01 5 speed transmission From a 1970 911.

-----------------------------------------------------

Thoughts please

Cya,
Sam C
__________________
1973 1303 (super beetle) in Jaguar British racing green,
Raby 2270, B spec gearbox, Lots of carbon fibre, Wolfrace Octane Black 17x7.5, Goodyear Eagle F1's, Kerscher suspension front and rear, kamei airdam in carbon, corbeau seats, momo millunium steering wheel.
CDT eurosport 6.5 front speakers, IDMAX 12D2 sub, rockford old school amps.
Reply With Quote
  #2  
Old August 14th 2002, 16:09
WipEout WipEout is offline
Registered User
 
Join Date: Aug 2002
Posts: 56
My suggestion would be to have your heads ported and polished (better flow= more power) while you replace the valves with 42mmx36mm sizes. That'll make for (you guessed it) better intake and exhaust flow. And from what I understand, those valve sizes are perfect for a 2ltr T-4 daily driver. My engine is a 2056cc with those valve sizes. It sounded great on the initial start up, but I've yet to get past the break-in procedures and actualy drive it. I should be taking a run down the street this weekend, though, so I'll let you know what kind of power the powerplant makes...



DAVID MANN
Reply With Quote
  #3  
Old August 14th 2002, 20:24
lightning bug's Avatar
lightning bug lightning bug is offline
Registered User
 
Join Date: Jul 2002
Location: Philadelphia, Pennsylvania USA
Posts: 462
I don't know much about T4 heads so I'll stay away from that part. I can tell you though to get a head with alot of meat on it. Especially around the intake ports. Also, try to find heads that are efficient in cooling. I see guys running CB comp eliminators on their street cars and they can't understand why their cars are running high CHT's. Those heads have like 3 cooling fins on them. You see what I'm getting at. The most expensive isn't always the most practical. Nothing against CB, I run CB 044's, the Comp Eliminators are for race applications. As far as head work goes, it all depends what you can spend. We all know that air flow is very important when trying to gain power. You can gain alot of power from headwork. In my opinion, get as much as you can afford to match your engine specs, unshroud the valves and MATCH PORT YOUR MANIFOLDS or else your head work really doesn't matter. Also, if you can, get your work done by someone with a flowbench. That way you know what kind of a difference you'll be making. Hope it helps.
__________________
Julian
'74 Super

"If you are under control you're going too slow" - Parnelli Jones
Reply With Quote
  #4  
Old August 15th 2002, 04:23
Oliver Knuf's Avatar
Oliver Knuf Oliver Knuf is offline
VW consumer products reseller and researcher
 
Join Date: Jul 2002
Location: Northrhine-Westphalia, Germany
Posts: 227
Red face ..

42/36 is a good size, that's also my opinion, but 41/34 will run as good with the E-cam, as the cam with hydr. lifters is more torquey and powerful up to 5000 rpm! Runned it x times with normal lifters and good p&p 1,8l heads. The tip above is also true, as you have to search for good cores, that should be not cracked and not too bended, as the heads get weaker over the time through the heat.
__________________
Click here to mail me!
Reply With Quote
  #5  
Old August 15th 2002, 04:29
SilverBullet SilverBullet is offline
Registered User
 
Join Date: Jul 2002
Posts: 428
On the topic of heads, I was wondering whether the dual valve springs are set in the same orientation or they counter each other? Any reason why?
Still on the learning curve!
Reply With Quote
  #6  
Old August 15th 2002, 04:37
Oliver Knuf's Avatar
Oliver Knuf Oliver Knuf is offline
VW consumer products reseller and researcher
 
Join Date: Jul 2002
Location: Northrhine-Westphalia, Germany
Posts: 227
...

That's a point, where I need the help of Alex to get it understand correctly, the counterwise is something, that I don't know, sorry!
__________________
Click here to mail me!
Reply With Quote
  #7  
Old August 15th 2002, 05:56
samcat's Avatar
samcat samcat is offline
Registered User
 
Join Date: Aug 2002
Location: Bristol, UK
Posts: 395
42/36 is where I was thinking of going with this. Paying for professionally put together heads from stateside tuning or someone like that.

3 angle valve job?
full port and polish
42/36 valves

Are there any other bits I should get done to the head at the same time?
What Valvetrain/rockers etc should be used (BEST)?

Cheers for the advice so far

Cya,
Sam C
__________________
1973 1303 (super beetle) in Jaguar British racing green,
Raby 2270, B spec gearbox, Lots of carbon fibre, Wolfrace Octane Black 17x7.5, Goodyear Eagle F1's, Kerscher suspension front and rear, kamei airdam in carbon, corbeau seats, momo millunium steering wheel.
CDT eurosport 6.5 front speakers, IDMAX 12D2 sub, rockford old school amps.
Reply With Quote
  #8  
Old August 15th 2002, 06:30
Oliver Knuf's Avatar
Oliver Knuf Oliver Knuf is offline
VW consumer products reseller and researcher
 
Join Date: Jul 2002
Location: Northrhine-Westphalia, Germany
Posts: 227
Talking ...

Hey, Stateside is ok, greet James from me, he's a fine pal! P&p the exhaust as big as you can get it, matchport both, intake and exhaust, an exhaust bracing is cool, but nothing that you have to do, but i would weld on the intake sealing surface to get a bigger seal on the head! Thin seals are fast away! Don't forget to resurface your valve cover side!
__________________
Click here to mail me!
Reply With Quote
  #9  
Old August 16th 2002, 09:21
stkmtr stkmtr is offline
Registered User
 
Join Date: Jul 2002
Location: Dallas TX
Posts: 15
uneven?

I have heard that the exhausts flow alot less that the intake ports-as Oliver hinted at. If your gonna send them all the way to the US I would be really careful. I have heard stories of heads being held hostage -taking over a year to be completed!! This was one of the most respected head shops here. You would probably be better off finding a shop that will work closely with you and build them to suit your needs-I would also make sure they have a flow bench to measure the % of int. vs. Ex flow. Gotta get it out b4 you put more in. I tried porting my own heads this last motor and I went toooo far. It's easy and expensive to get carried away. I deshouded the valves to much and messed up the barrel sealing surface! I was confident because I had done plenty of "Fluff & Buffs" to aftermarket heads. Making killer heads out of stockers is a whole different ballgame. What do you want to spend? By the time you ship them to the us and buy parts you are looking at alot of time you could have spent hitting some apexes-SS

Last edited by stkmtr; August 19th 2002 at 14:22.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes

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

Forum Jump


All times are GMT -4. The time now is 19:31.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
© www.GermanLook.net 2002-2017. All Rights Reserved