Home » Catalog » Big Valve Heads » Technical Information  
Product Categories

Location: Home » Catalog » Big Valve Heads » Technical Information

Technical Information

    Valve sizes must be changed in corresponding sizes in relationship to one another. Installing any larger valve sizes requires the removal of the heater boxes and the use of a large tube competition exhaust system, such as GB 932S or larger, dependent upon engine combination and application. Running through a stock restrictive size pipe will cause overheating and you will not achieve maximum performance gain from the larger valves in the system. In fact, you likely will have a loss of low end torque and difficulty tuning the engine for smooth operation. Flat spots are often a problem due to the low air speed from the improper vacuum rate and when larger jets are installed an over rich condition occurs at a higher RPM as the pressure increases. The engine RPM will still be governed at the same point as before by the remaining restrictive part in the system. If you have the wrong size at any location it becomes the restriction, causing an out of balance of the system. It is not practical to increase the size of the intake valve if you still use the stock size exhaust.
    This reduces the intake speed greatly and decreases the signal sent to the carb as no gain is made in the exhaust to overcome this loss of air speed. Furthermore, the restriction at the exhaust of hot gasses is just what was done to smog engines that must run at higher than normal temperatures to burn the emissions. You know the ones that are famous for flat spots and too high of head temperatures. If larger exhaust valves are added then the restrictor is the exhaust pipe and heater boxes. All manufacturers of engines use a formula to determine proper combinations to provide the correct balance to achieve proper running, cooling and longevity of the engine. For more on heads GB 801-HEADS is required reading.


     Product Name   Description   MSRP Price   Our Price+   Cash Price 
     GB 860  Same as GB 855 dual port with Manley 40mm intake and 35.5mm or 37.5 exhaust valves installed (specify exhaust valve size or ask for assistance when placing the order), ported, polished, reshaped chambers, Berg's 3-angle valve job, GB 273A dual springs, shims, GB 344 keepers, Berg seats and GB 281A retainers. Bored to size of your choice. Semi-Hemi included unless told not to. Requires at least 1-1/2" exhaust system and dual, dual throat carbs such as our 42 specials. The exception to this would be special race applications that use a wild cam and two 2 barrels or one 2 barrel. Specify if being used on a bus. SW 32# per pair.   $2,343.00   $1,650.00   $1,650.00 
     GB 861  Same as GB 860 includes the labor to port and polish our manifolds (price of manifolds additional). Requires at least 1-1/2" exhaust system and dual, dual throat carbs such as our 42 specials. The exception to this would be special race applications that use a wild cam and two 2 barrels or one 2 barrel. SW 32# per pair.   $2,485.00   $1,750.00   $1,750.00 
     GB 865  Dual port, Manley 40mm intake and 37.5mm exhaust valves, welded above and below the intake ports, ported, polished to larger gasket size and are match ported to manifolds (price of manifolds additional). Reshaped chambers, Berg's 3-angle valve job, GB 273A dual springs, shims, GB 344 keepers, Berg seats and GB 281A retainers. Bored to size of your choice. Semi-Hemi included unless told not to. Requires at least 1-5/8" exhaust system. Specify if being used on a bus. SW 33# per pair.   $2,852.85   $1,995.00   $1,995.00 
     GB 865C  As GB 865 with Chevy type springs for applications with PEFI.   $2,542.60   $1,849.17   $1,778.05 
     GB 870  Dual port, Manley 43.7 intake and 37.5mm exhaust valves, welded above and below intake ports, ported, polished to larger gasket size and match ported to manifolds. Manifolds extra. Spark plugs relocated to clear bigger valve seats and increase reliability. (This is a must with 42mm intake seats, otherwise when the plug is installed it can pull the seat out of alignment). Reshaped chambers, Berg's 3-angle valve job, GB 272A Chevy type springs, GB 284 shims, GB 344 keepers, Berg seats and GB 283A heat treated chrome moly retainers. For high output/higher performance we recommend our GB 272BR springs which can be upgraded at an additional cost. Intake port bump is welded up to accommodate the larger Chevy type spring. Spring seating area welded and re-machined to captivate springs. This prevents spring breakage and fatigue providing far greater life. Pushrod tubes relocated for best ratio rocker arm clearance and large enough to accept the VW 025-109-335 pushrod tube and VW 070-109-345 seal. Includes porting and polishing labor of intake manifolds (price of manifolds additional). Bored to size of your choice. Semi-Hemi included if you desire, specify. Requires at least 1-5/8", or better yet 1-3/4", exhaust system. Inquire if you have other head needs to go with the engine parts you are buying from us. We can normally supply your needs as part of our commitment in supporting you for buying our parts.   $3.00   $2.00   $2,236.00 
     GB 872  Same as GB 870 except with 1-3/4 (44.45mm) by 1-1/2 (38.10mm) titanium valves, GB 272BR Chevy type springs (labor to weld up intake port bump to accommodate the larger Chevy type spring), GB 277A titanium retainers, GB 284 shims. Seats installed with extra press, top fin welded and milled flat if for high compression. This is to prevent head flex and breakage caused by the head being torqued with top fin being cut off. Includes flow checking after head is ported and equaling all ports to close tolerances.   $4,382.95   $3,187.60   $3,065.00 
    Displaying 1 to 6 (of 6 products) Result Pages:  1 

     

     

    Quick Find
     
    Use keywords to find the product you are looking for.
    Advanced Search
    Information
    Business Hours
    Phone Service
    Placing Orders
    Shipping Policies
    Returns For Credit
    Warranty Policy
    Privacy Notice
    Disclaimers
    Contact Us

    Web design and hosting by Canvas Dreams LLC and California web design by Pearl Compass.

    Please contact us about errors or questions. We value your input!

    Any and all references to the company Volkswagen, or the VW name are strictly for reference only. The GENE BERG name and GENE BERG products are protected under trademark, copyright and patent law, any violations will be pursued. GENE BERG ENT. is not a part of any companies mentioned or linked to this website and any beliefs of those companies are not necessarily the beliefs of GENE BERG ENTERPRISES.Site maintained by xanax side effects

    Copyright ©2017 GENE BERG ENTERPRISES all rights reserved