Tomorrow's Technology for Today's Classics and Beyond

BMW, Moto Guzzi, Triumph, Norton, and more...












Bombar's Beemers is a leader in head reconditioning

Don't take our word for it...

"Wow - the power this bike has with the new re-conditioned heads is truly great. 

I am enjoying this bike all over again...Thanks" 

 - John S '81 R100


"Peter - You took an old head that was bad and transformed it into a working piece of art.  This bike has power it never had before - Thank you for a great and careful job"

 - John P - '74 BMW R90S


"...recessed valve seats, old clapped out valves, rusted cylinder...  The list went on.  And now I have a GS that runs better than ever before.  Great job"

- John D - '93 BMW R100GS


"Peter - You bored and honed and rebuilt my entire power plant.  It's a working piece of art.  It runs so well."

 - John L - '72 BMW R75/5


"The Triumph TR-140 heads you rebuilt make this bike sing.  Thanks Peter for a job well done"

 - Jesse - '74 Triumph T140 Bonneville


"My Norton 850 is GOLD!!!!   Thanks to you I have a great and completely rebuilt engine, heads and carbs.  Runs perfectly!!!"

 - Maurice - 1975 Norton 850


"Great job on my heads!!  Not everyone can do headwork on a 1957 Heinkel Tourist.  You did and it runs great"

- Rick Jones - Motorrad Elektrik


"My heads and engine are amazing"

- John W - 1978 BMW R75/7 modified to 1000cc


"OK - You did it - It's running smooth and strong again - Great head work."

- John - 1995 BMW R1100GS


"Amazing power and runs better than ever"

- Robert. 1980 Moto Guzzi Le Mans


"Really Great.  What a great bike again!!"

- Cody. 1970 Moto Guzzi 750






























































































Therefore, all Airhead engines from 1970-1984 most

likely need to have a valve job 
wherein the exhaust seats (and valves) are replaced and the intakes are examined. 



This is from a R60/5

        * Cost depends on what is needed, repaired, special seats, special angled cutting, and custom porting.



  • NEW VALVES, GUIDES, SPRINGS, and if needed…

  • UNLEADED Exhaust Valve Seats ('70 -’87 models) precision cut with up to 5 angles.

  • Labor with exhaust seat from $599/pair*

  • Labor w/o valve seats from $519/pair*

  • Parts costs for ’75-’87 models from $425

  • Parts Costs for ’88 & on models from $360


We replace the damaged exhaust threads with a new and better sleeve.  The sleeve is an interference fit and  pinned to the cylinder.  This is a stronger and excellent repair which avoids future failures. 

We do not recommend replacing the seats on vintage heads unless they are completely unrepairable.  Our experience has shown that a top end recut of the valve seats is all that is needed.   These seats are tough!


Prices may vary on Moto Guzzi specific models. 

We can also port the heads for increased flow.

We also repair/refurbish your late model R series Oilhead and Brick K Bike head components.  Price from $649 plus $209 for essential parts/pair

Your heads will have perfect seats allowing for increased power and great performance.  Look at this picture.  This BMW head had an exhaust valve with 5 thousands of runout (.005), which is way too much for a cylinder head.  It will run OK, but lacks that crisp top end horsepower.  After inserting a new exhaust seat, and cutting the seat with three angles the measurement was checked as well as vacuum.  The result is less than one thousands (.0005) total runout and holds a perfect vacuum of -26 In Hg.  This head will develop about 15% - 20% more power than the original.  This is the quality we provide to every job that comes through our door. 

No stone work!

We offer the best machine shop services using CNC equipment

to rebuild your entire engine.





Expert and Complete Engine and Cylinder Rebuilding.

Dis-assembled, Bead Blasted and Cleaned, Repaired, and Re-assembled. New Parts As Needed. 

Prices on request.


A Completed Engine - A Real Beauty! 

We can replace your worn out and rusty push rod tubes with

a set from Keihan. These Stainless Steel tubes are an

excellent choice when rebuilding your cylinders

as seen in the picture

1934-R4 BMW
Hinkel Head
Pre-War, WWII, Post War Vintage heads for BMW, Heinkel, Norton, Triumph, Zundapp, to name a few. 

1955 Hinkel Head

1934 BMW R4 Head


1943 BMW R70 Head

1974 T-140 Triumph Bonneville 750 head being rebuilt

British head reconditioning.

1974 - Norton 850 Commando head and cylinder all redone and ready to go. G&S Valves, Custom valve guides, three angle SERDI cut onto new inserted SBI valve seats, the cylinder top decked and all valves hold perfect vacuum!  The cylinders were bored and honed first over and have new pistons and rings.  This Norton 850 will run great!!


Bring us your component or the entire bike and we can arrange for restorative repairs.

We are happy to give you a base estimate at no charge.  

Valve and Valve Seat Tech

The advent of unleaded fuels brought about two problems with BMW valve trains. The 1970-1980 models had valve seats that were not strong enough (iron seats) to survive without the lubricating properties of soluble tetraethyl lead. The harder rotating valve against the seat (almost exclusively the exhaust side) wore the seat out and created a condition known as valve seat recession (VSR).  BMW slowly addressed the VSR problem and in the 1981-1984 models the valve seats were made of much tougher material (stainless steel, high nickel/chrome-alloy). However, this created a second problem called valve face plastic deformation (VFPD) wherein the valves themselves were getting beat up as the new material was a poor heat conductor. The R100 engines suffered the most as they create the most heat. In addition, EPA mandated advanced timing, lean jetting, and the pulsed air emissions system that all contributed to adding heat to the exhaust side where the exhaust valves were deformed to where they no longer sealed properly.  Finally, the third generation of valve seat material came out with the 1985 and later models and the valve problems were solved (for the most part).  

© 2017 Bombars Beemers LLC