| [ Total Views: 667 | Total Replies: 10 | Thread Id: 53181 ] |
|
|
 jonno-t3
A.k.a.: johnathon cooper
Officially Full-On Dubber
Posts: 289
Threads: 53
Registered: April 26th, 2003
Member Is Offline
Location: campbell town, tas
Theme: UltimaBB Pro Blue ( Default )
Mood: stewed
|
 posted on June 11th, 2006 at 08:41 AM |
|
|
rebuilding my engine. few questions if someone knows
hey all. i am rebuilding my t3 motor down here in tas. nothing spectacular. slightly bigger barrels and a shaved head if i can.
what i was wondering is, how far can i get the head shaved if at all and also if i get the 87mm piston/barrel set, do they go on the stock block? and
can i fit a better crank in the block and/or would that be worth it?
also i am taking off the cooling fan at the front. i hate it. so what i was thinking was using twin squirrel fans i think they're called, on top of
the barrels/heads, with a . does anyone know of another method of cooling under these conditions? and one more thing.:P i was going to use the stock
carbi's and get them re-jetted. is this possible? or a new carb set be better? what to use?
thanks, jonno
"if only everything in life was made like a volkswagen"
 |
|
|
68AutoBug
A.k.a.: Lee Noonan
Aircooled Master
Beetle Restorer - Experience over 138% - YIKES --
Posts: 11654
Threads: 449
Registered: August 31st, 2002
Member Is Offline
Location: SCONE in UPPER HUNTER VALLEY NSW
Theme: UltimaBB Pro Yellow
Mood: Really Mentally Ill - all of the time -
|
| posted on June 11th, 2006 at 10:36 AM |
|
|
A shaved head will higher Your compression....
not a good idea with VW engines....
means extra Heat.....
I've sent You some info pages to your hotmail address.
Lee
- [size=4]Helping keep Air Cooled VWs on the road - location: SCONE in the Upper Hunter Valley - Northern NSW 320 kms NNW of SYDNEY--- [/size]
|
|
|
koolkarmakombi
Veteran Volks Folk
enkarmarising
Posts: 2078
Threads: 158
Registered: June 16th, 2003
Member Is Offline
Location: viva brisvegas
Theme: UltimaBB Pro Blue ( Default )
Mood: do you see the bats?
|
| posted on June 11th, 2006 at 10:58 AM |
|
|
Read the gene berg website
This disclaimer does not reflect the thoughts or opinions of either myself, my company, my friends, or my dog: don't quote me on that; don't
quote me on anything; this disclaimer is subject to change without notice; text is slightly enlarged to show detail; resemblance to actual persons,
living or dead, is unintentional and coincidental; dry clean only; do not bend, fold, or mutilate; anchovies or jalapenos added to this disclaimer
upon request; your mileage may vary; no substitutions are allowed; for a limited time only while supplies last; offer void where prohibited; this
disclaimer is provided "as is" without any warranties expressed or implied
|
|
|
 Bizarre
Super Moderator
The artist formerly known as blue74l
Posts: 12780
Threads: 734
Registered: August 25th, 2002
Member Is Offline
Location: Abbotsford, Sydney
Theme: UltimaBB Pro Blue ( Default )
|
| posted on June 11th, 2006 at 11:08 AM |
|
|
Jonno
Yes you can shave (or more correctly - fly cut) where the barrels sits in the head.
As Lee said this will increase compression ratio. To compensate you need to open up the head chamber
This is all dependent on what deck height you have - the gap at TDC from the top of the piston to the top of the cylinder
87s are slip ins. No maching required.
For what you are doing a stock crank is fine
Cooling - leave it alone!
I know a few people experimenting with different fans, but they are very experienced. The stock fan moves a truck load of air.
You WILL cook your motor if you try doing something different
Stock carbs can be rejetted - but i doubt you need to
Here is another good site to read up on
http://www.aircooled.net/gnrlsite/resource/articles.htm
and here is Gene Berg's site
http://www.geneberg.com/index.php
Futue te ipsum!!!
|
|
|
1500S
Custom Title Time!
Posts: 1418
Threads: 73
Registered: March 28th, 2005
Member Is Offline
Location: Nth Richmond, N.S.W
Theme: UltimaBB Pro Blue ( Default )
|
| posted on June 15th, 2006 at 10:11 PM |
|
|
>Yes you can shave (or more correctly - fly cut) where the barrels sits in the head.<
For cyls above the 87mm it can be done on either a lathe or milling machine. Actually the correct term is bored and faced! A flycutter is actually
a single point tool used in a milling machine for surface milling in place of a multi tip cutter. A flycutter is also a single point form tool for
special shapes. If a flycutter was used to do the facing with such a broad surface a fair ammount of chatter would result in a poor seating surface
for the cylinders. Sorry to point this bit of engineering out but some motor mechanics do screw up machining terms!
If you have a mate with a minimum 6 1/2" centre lathe and a large enough face plate to hold the VW heads they are quite easy to machine. A milling
machine is that other nice piece of luxury but tooling is that bit more expensive as you need a boring and facing head to do a good job.
DH
[ Edited on 15/6/2006 by 1500S ]
|
|
|
jakjones
Officially Full-On Dubber
Posts: 217
Threads: 3
Registered: March 9th, 2004
Member Is Offline
Location: central coast
Theme: UltimaBB Pro Blue ( Default )
Mood: Settled
|
| posted on June 16th, 2006 at 12:06 AM |
|
|
| Quote: | Originally
posted by 1500S
>Yes you can shave (or more correctly - fly cut) where the barrels sits in the head.<
For cyls above the 87mm it can be done on either a lathe or milling machine. Actually the correct term is bored and faced! A flycutter is actually
a single point tool used in a milling machine for surface milling in place of a multi tip cutter. A flycutter is also a single point form tool for
special shapes. If a flycutter was used to do the facing with such a broad surface a fair ammount of chatter would result in a poor seating surface
for the cylinders. Sorry to point this bit of engineering out but some motor mechanics do screw up machining terms!
mmmmm
a single point HSS fly cutter works fine from what I've seen.
cheers
[ Edited on 15/6/2006 by 1500S ]
|
|
|
|
1500S
Custom Title Time!
Posts: 1418
Threads: 73
Registered: March 28th, 2005
Member Is Offline
Location: Nth Richmond, N.S.W
Theme: UltimaBB Pro Blue ( Default )
|
| posted on June 16th, 2006 at 08:23 AM |
|
|
Mmmmmm! Can you post a photo of this setup? As a cut of some 15 mm wide is required to re-face the cylinder seat/combustion chamber area. Quite
some machine to do the job without chatter so I would be very interested in the setup as would other professional machinists in the group!
DH
|
|
|
PurpleT3
Fahrvergnugen
Posts: 880
Threads: 55
Registered: April 8th, 2003
Member Is Offline
Location: Knox, Melbourne
Theme: UltimaBB Pro Blue ( Default )
Mood: knackered
|
| posted on June 16th, 2006 at 09:57 AM |
|
|
Flycutting, by whatever method, is sometimes done to true up the mating surfaces on the heads. The increase in compression can be compensated for by
using shims to return original deck height. It is not necessary unless your heads are warped or otherwise damaged, in which case you would be advised
to replace them.
What is wrong with the cooling fan? Unless you are an expert, DO NOT MESS WITH THE COOLING SYSTEM or you can kiss you rebuilt engine goodbye.
There is another thread on this theme. If you want a bit more oomf, 1:1.4 rockers, weber carbs, extractors. All these things can be added without
taking the engine apart. Maybe consider installing a mild cam while the case is open.
I'm no expert on machining, but I have only ever heard it referred to as "fly cutting"
Ain't nothin' like the wind in your hair.
|
|
|
1500S
Custom Title Time!
Posts: 1418
Threads: 73
Registered: March 28th, 2005
Member Is Offline
Location: Nth Richmond, N.S.W
Theme: UltimaBB Pro Blue ( Default )
|
| posted on June 16th, 2006 at 10:31 AM |
|
|
You are right there PurpleT3. The term is used in general for many things. We use a balanced flycutter (weighted to prevent out of balance) to
machine normal heads such as Fords etc. On our beloved VW heads we are re-seating the cylinder holes in the head if they require it (and generally
they do). There were aluminium shims available to bring the engine back to standard comp if too much is taken off. When we open the heads out to
accept 1916 pots etc, we are boring and facing the recesses. That can be done with a suitable flycutter but it does require a machine with a solid
spindle to prevent chatter. It is better with an odd number of teeth on the cutter which requires the tips to be ground exact on a Tool and Cutter
Grinder. So that depth the recesses are equal it can be an advantage to take a light facing cut over the bottom of the head to give a full face
rather than the 6 little lumps. That way it is easy to measure seat depth with a depth micrometer. If not, we have to generally rely on the zero
from a scale or DRO. As for tooling, a facing and boring head for tha mill is the prefered option but will set you back somewhere between $1300 and
$2000! You need to machine a few heads to make it pay.
Too much info for the casual engine builder! Sometimes a centre lathe is the better option as a simple boring bar does both boring to accept larger
pots as well as facing to the same depth. The rocker cover face of the head can be used as a datum in this case but still better to skim bottom face
and depth mic from there.
Phew!! But this is a technical section of the forum!
DH
[ Edited on 16/6/2006 by 1500S ]
|
|
|
VWCOOL
23 Windows of Awesome
Posts: 5158
Threads: 235
Registered: June 19th, 2003
Member Is Offline
Location: In the shed... Lake Macquarie NSW
Theme: UltimaBB Pro Blue ( Default )
Mood: happy to help
|
| posted on June 16th, 2006 at 12:07 PM |
|
|
Until you learn a bit more, maybe you would be better buying a second-hand performance engine. Saves a lot of dramas, expense and heartache!
Pay your debts, CxxT
|
|
|
jonno-t3
A.k.a.: johnathon cooper
Officially Full-On Dubber
Posts: 289
Threads: 53
Registered: April 26th, 2003
Member Is Offline
Location: campbell town, tas
Theme: UltimaBB Pro Blue ( Default )
Mood: stewed
|
| posted on June 24th, 2006 at 04:49 PM |
|
|
thanks for all the info guys. i will look into this cooling further. i have seen heaps of vw motors without the cooling on there, but they all had the
full flow oil systems, which i was going to do, but maybe they're doing something else. also whats a gearbox reco worth? and can u get different
ratio sets for it for different tyre sizes etc. and does anyone know of a good place to get an airconditiong kit? the ones the hot rodders use with
the chromed pumps?
cheers again, jonno
"if only everything in life was made like a volkswagen"
|
|
|
