QUOTE(Bleyseng @ Nov 15 2010, 09:31 AM)
Look at this for head info on the LE180 -http://www.aircooledtechnology.com/index.php?option=com_content&view=article&id=82&Itemid=96-
this is fairly technical but there isn't a "How to Preformance rebuild 914 Heads for Dummies" youtube video that I know of its how Jake and Len make their living.
Raby 95-- cam/valve train upgrade kit works fantastic with Djet.
cylinders bored out to 96mm with new Keith Black pistons to match...
CR from 8 to 9 to one
Rods have notched for oil squirting
balance everything!
Really, if you just want to build without hassle the "Best" 2056 engine just order a kit as its all ready to assemble with parts that fit with the proper clearances. Buying parts from all kinds of different suppliers will create some difficulties but you will learn alot !
Ok got it now, thanks, hard for me to find the info on rabys site, he has a lot of stuff on it
see below:
"Technical specifications for the RAT LE 180-914 cylinder heads:
Head casting type- NEW 2.0L Bus castings modified to 2.0/914
Combustion chamber shape- exact digitized replica of the 2.0-914 combustion chamber
Combustion chamber volume- 56cc+/-
Spark plug location- 2.0 914 location. Plug relocated from conventional location to promote efficiency, chamber strength and aesthetics for 2.0 engine owners.
Spark plug diameter- 12mm, reduced from 14mm to enhance chamber strength and help resist cracking related to potential over heating (should it occur)
Valve sizes- 42mm Intake/ 36mm Exhaust
Port work- Fully digitized CNC machined intake and exhaust ports that flow within 2% of the OEM 2.0 914 cylinder head!
Valve type- Stainless Steel
Valve Springs- RAT single heavy duty. Will control valves to 6,250 RPM +/- dependant upon camshaft and valve train mass.
Valve spring pressures- 215#@ .500 lift/ 120# seated
Retainers- Chromoly steel
Intake manifold pattern- original 4 stud pattern, no alterations made. Port matched manifolds are not included in the price. Installer is responsible for port matching manifolds. OPTIONAL "3 studding" available at added expense
"
so what I gather is offered by raby is a new bus head modified to replicate the 2 liter 914 head with smaller diameter spark plug threads but same chamber and ports. and same valve sizes. does this seem right?
So it appears I can fix my heads to be more or less the same not sure if i will change the plug hole or not.
so the stock valves work with the raby cam (still have no idea which cam to choose, several are offered)
I also see Elgin cams offers some choices on performance cams that are D-jet compatible, (for example 330 cam(shown in bold print below)) has any one used these cams? It was suggested by Elgin to clearance some metal on the heads that support a stud (if I remember right) that should help performacne. has anyone done that modification?Elgin Cams listing:......................................
"PORSCHE 914 PROFILES
On the 7208 and wilder grinds we recommend having a slot cut down the middle of the timing gear to create two rows of teeth. This helps reduce oil throw off and oil foaming at high rpms.
Lifters must always be reconditioned or replaced. Beware of aftermarket 914 lifters, some of them are of very poor quality.
INTAKE ROCKER ARM RATIO = 1.3:1 EXHAUST ROCKER ARM RATIO = 1.25:1
GRIND NO.
SEAT DURATION
CAM LIFT
LASH
APPLICATION
64508-H
258
258
.294
.294
I HYD.
E HYD
HYDRAULIC LIFTER.
WILL WORK WITH F.I.
6508-H
260
260
.292
.292
I HYD.
E HYD
HYDRAULIC LIFTER STREET GRIND A LITTLE ROUGH WITH F.I.
68508-H
274
274
.302
.302
I HYD.
E HYD
PERFORMANCE HYDRAULIC, MORE COMP, & GOOD EXH. SYSTEM.
914
255
254
.296
.282
I STD.
E STD.
STOCK SOLID LIFTER GRIND.
330-1
256
255
.296
.296
I STD.
E STD.
IMPROVED STOCK. MORE LOBE AREA THAN STOCK. GOOD W/ F.I. 6408-18
256
256
.296
.296
I STD.
E STD.
WIDE TORQUE BAND. A LITTLE ROUGH WITH FUEL INJECTION.
66508-19
266
266
.305
.305
I STD.
E STD.
CARBS REQUIRED. SMOOTH IDLE, 1500-4500 RPM.
M6708-18
268
268
.314
.314
I STD.
E STD.
REQUIRES CARB AND A GOOD EXHAUST SYSTEM.
7008-17
280
280
.333
.333
I STD.
E STD.
BIG BORE KIT, CARBS, 9:1 AND HEADER, 2000-6000 RPM
7208-17
288
288
.333
.333
I STD.
E STD.
BIG BORE KIT, 9.5:1, CARBS, AND HEADER 2500-6000 RPM
7207-19
288
288
.369
.369
I STD.
E STD.
HOT STREET - AUTOCROSS. 9.5+:1, 2500-7000 RPM.
7508-18
300
300
.350
.350
I STD.
E STD.
AUTOCROSS. 10.5:1, 3800-7300 RPM.
7708-17
308
308
.369
.369
I .008
E .010
FULL RACE. 11.5:1, 3800-7300 RPM.