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Shaving the head for bigger bangs

I have a few real beginner questions for you folks. Is there a difference between shaving, skimming and decking? Is one for the head while the other is for the block?

Also, if you remove material from the head that means that the valves will now be closer to each piston. If you use a high lift cam such as a "k" cam then the valves may collide with the pistons if too much metal is taken off of the head. Is that correct?

What exactly does shimming mean? Are the valves or is the cam shimmed? Is the idea there to keep the valves from hitting the piston?


Thanks for your help.
 
Fred Gwynne, ya gotta start your own thread for those questions, we don't do threadjacking here.

Hessam, what car/engine combo are you talking about? A lot of people have thrown opinions in here, maybe they know what you have, but you haven't stated if its a factory turbo motor, a +T or NA, that makes a huge difference in the answers you will get.
 
Fred Gwynne, ya gotta start your own thread for those questions, we don't do threadjacking here.

or just answer his questions.

I have a few real beginner questions for you folks. Is there a difference between shaving, skimming and decking? Is one for the head while the other is for the block?

Also, if you remove material from the head that means that the valves will now be closer to each piston. If you use a high lift cam such as a "k" cam then the valves may collide with the pistons if too much metal is taken off of the head. Is that correct?

What exactly does shimming mean? Are the valves or is the cam shimmed? Is the idea there to keep the valves from hitting the piston?


Thanks for your help.

You can shave the head. Take a bit off. Yes to the valve q. It also raises cr or is just used to correct a warped head.

You can deck a block... similar concept. This brings the pistons closer to the head. Used to correct a block surface or decrease squish clearance. There are some performance benefits to this.

You can also get the pistons closer to the head by using a thinner headgasket.

In a Volvo application shimming refers to changing the distance between the camshaft and the lifters. Typically by adding or removing shims of a specific thickness.

To keep a valve away from the piston typically you cut a valve relief into the piston top.
 
Skimming is the English word and shaving is the US word for removing material off the cylinder head.

Decking is removing material from the block
 
I know people who have shaved the head down on the Penta series. These motors are old now and people have shaved them down a bit due to warping.
 
Fred Gwynne, ya gotta start your own thread for those questions, we don't do threadjacking here.

Hessam, what car/engine combo are you talking about? A lot of people have thrown opinions in here, maybe they know what you have, but you haven't stated if its a factory turbo motor, a +T or NA, that makes a huge difference in the answers you will get.



I apologize for what seemed, to you and possibly others, to be my attempt to threadjack. I had assumed that my questions were directly related to the title of this thread but apparently they are not.
 
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I apologize for what seemed, to you and possibly others, to be my attempt to threadjack. I had assumed that my questions were directly related to the title of this thread but apparently they are not.

You're fine. Thread derailment is par for the course here.

I have a few real beginner questions for you folks. Is there a difference between shaving, skimming and decking? Is one for the head while the other is for the block?

Also, if you remove material from the head that means that the valves will now be closer to each piston. If you use a high lift cam such as a "k" cam then the valves may collide with the pistons if too much metal is taken off of the head. Is that correct?

What exactly does shimming mean? Are the valves or is the cam shimmed? Is the idea there to keep the valves from hitting the piston?


Thanks for your help.


"Deck" usually refers to material being machined from the block deck, but it also get's thrown around when talking about machining a head to reduce the chamber volume or to clean it up.

"Shaving" refers to just the head.

Running an aftermarket camshaft will usually result in the engine becoming an interference engine. A large percentage of engines are interference by design, I don't worry about it at all.

"Shimming" is setting the valve clearance using valve shims.
 
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You're fine. Thread derailment is par for the course here.




"Deck" usually refers to material being machined from the block deck, but it also get's thrown around when talking about machining a head to reduce the chamber volume or to clean it up.

"Shaving" refers to just the head.

Running an aftermarket camshaft will usually result in the engine becoming an interference engine. A large percentage of engines are interference by design, I don't worry about it at all.

"Shimming" is setting the valve clearance using valve shims.

Right on, I appreciate your help.
 
In for a penny, in for a pound. :google:
The reality is, skimming is minor compared to what the Swedes and Norwegians do.
Here is a Norwegian thread about porting the 530 with bigger valves.
I'm pretty sure somewhere in this one is a guy relocated the head 3 mm to the exhaust side to fit bigger valves.
http://forum.vccn.no/showthread.php?36369-Porting-av-530-398-160-topp!/page8
You can google translate it, or just scroll through the pictures.

Holy moly. 12 pages in from the beginning plus I stated at page 20something. Lots of info and kind of fun to see the Swedes pick at each other's ideas. I hadn't seen a discussion of compression vs valve size in the way they are speaking of it. Also, really have to struggle as some words they use we do, not to mention the translator is only capable of so much.

Some of the chamber shots in that thread are beautiful.
 
You're fine. Thread derailment is par for the course here.




"Deck" usually refers to material being machined from the block deck, but it also get's thrown around when talking about machining a head to reduce the chamber volume or to clean it up.

"Shaving" refers to just the head.

Running an aftermarket camshaft will usually result in the engine becoming an interference engine. A large percentage of engines are interference by design, I don't worry about it at all.

"Shimming" is setting the valve clearance using valve shims.
Let's not get into perceived absolutes.

No thread-jacking in Performance or maintenance, sales, etc.
If the OP joke around, it's generally cool. But posting the crusher (Ken), etc. is frowned upon.

The deck of the block is pretty standard, could be lots of stuff in other worlds, never means the gasket surface of the head. Machining, cutting, whatever can be done to the deck or the head. "decked" means the deck of the block has been cut.
You can shim lost of things, including a head gasket if too much is missing from either surface.
 
From the Swedish site. What is comb?

". My suction I run a relatively gentle comb on, and has 12.2: 1 in compression, where even the dynamic mandrel is higher than the engine had geometrically original. does not knock on mine before I go smoothly over 40 ? on torque peak, while max torque is picked up at just over 30 ?, ergo little point to pull on more ignition if it both slows down the effect and makes bank."

Gentle comb =mild cam?
 
From the Swedish site. What is comb?

". My suction I run a relatively gentle comb on, and has 12.2: 1 in compression, where even the dynamic mandrel is higher than the engine had geometrically original. does not knock on mine before I go smoothly over 40 ? on torque peak, while max torque is picked up at just over 30 ?, ergo little point to pull on more ignition if it both slows down the effect and makes bank."

Gentle comb =mild cam?

Screw online translators:oops:...they can't do car stuff or normal 'snack'.They're too proper and don't know car parts names......gimme the direct thing copy paste or link.. Somewhere up above there was link to Norski Volvo owners club but that's close enough to Swedish, just sounds like they come from the Ozarks
 
http://i31.photobucket.com/albums/c352/142volvo/PICT0123.jpg

PICT0123.jpg


Some pics of a 530 cc from on that Swedish site.

This particular guy argues for no protrusion of the valve guide in the intake tract.

Details on post #884 on that thread
 
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Screw online translators:oops:...they can't do car stuff or normal 'snack'.They're too proper and don't know car parts names......gimme the direct thing copy paste or link.. Somewhere up above there was link to Norski Volvo owners club but that's close enough to Swedish, just sounds like they come from the Ozarks

John,

You were right about it being from the web site posted on page one. I went thru all 38 pages translating probably 70% of those posts. :wtf:

Funny to see them crack on politicians and beat each other up too. Peak.. I figure there is some slang just like we use that doesn't translate.

http://forum.vccn.no/showthread.php?36369-Porting-av-530-398-160-topp!/page36

this link is to the page from which the pics above were sniped.
 
John,

You were right about it being from the web site posted on page one. I went thru all 38 pages translating probably 70% of those posts. :wtf:

Funny to see them crack on politicians and beat each other up too. Peak.. I figure there is some slang just like we use that doesn't translate.

http://forum.vccn.no/showthread.php?36369-Porting-av-530-398-160-topp!/page36

this link is to the page from which the pics above were sniped.


It is Norwegian, I'm a memeber---by invite from the Big Cheese Head Moderator..If you were tanslanting that Norsk using Swedish it'll come out even lousier... I'll be back later and show you the BEST translator...gotta cook dinner.

But can you find that particular bit you posted oilier?
 
It is Norwegian, I'm a memeber---by invite from the Big Cheese Head Moderator..If you were tanslanting that Norsk using Swedish it'll come out even lousier... I'll be back later and show you the BEST translator...gotta cook dinner.

But can you find that particular bit you posted oilier?

I was dreading going back through all that again. I did switch the translator to Norwegian and indeed some words changed "tracks' became 'grooves" when speaking of the Singh grooves and I got lucky and found a reference to "cream" in post #778 on this page.

http://forum.vccn.no/showthread.php?36369-Porting-av-530-398-160-topp!/page32

" Muligens "Monkey see monkey do" Som de fleste i Rob & Duplicate bransjen... vi VET at en port som er stor nok til ? f?de ventilvinduet opp til L/D 0.25 vil g? bedre enn den ur?rte originale som ikke gj?r det. Graver man st?rre enn det igjen og hvertfall hvis man ikke kj?rer mer l?ft enn L/D 0.25 s? har man fortsatt ikke noe mer fl?de, bare en latere port uten noe s?rlig hastighet, eller man har i praksis gjort 530'n om til en 531...

Flere kunder f?r man seff av ? ?ke arealet opp dit at toppen faktisk fl?der nok til at det er ventilvinduet som blir begrensinga, fordi det funker bedre enn det kliss originale hvor det ikke er ventilvinduet som er troppa. Kunden merker at det er forskjell i positiv retning kontra original og anbefaler s? denne jobben til neste mann som lurer

Skal det funke enda bedre innenfor alfabet-l?ft kan man lage gener?s back-cut p? ventilene og gj?re setevinkelen noe smalere s? innerdian p? setevinkelen ?ker, feks med en vinkel ekstra i seteinnsatsen, for ? flytte ventilvinduet lengre ut s? dette blir st?rre for ethvert l?ft... Rydder man s? lett opp i brennkammeret og gj?r det mer symmetrisk ala bedre-brennende VAG 2v topper, s? blir det dertil ogs? et enda bedre resultat, ikke bare fordi det samtidig fl?der noe bedre, men fordi man utnytter det man har f?tt inn bedre ogs?. Feks. er den originale Volvo l?sningen med ubrukte squish-flater i toppen som stikker ut over gropa i stempelet en direkte ?delegende aff?re, evt. kan man f? "customstempeler" som gjenspeiler squish-flatene, men det igjen er ikke en billig aff?re og noe man kun helst foretar seg p? et litt mer seri?st NA-bygg hvor man ogs? vil holde kammeret noe mer kompakt (p? et vis er jo ? basere seg p? en 530 litt skivebom i utgangspunktet hvis ikke regler osv forbyr feks. 16v), og da er brennkammer mod. en bedre l?sning i de aller flestes tilfeller.

Det som er litt interessant er at den modifikasjonen jeg og Bj?rn gj?r, gj?r akkurat det samme, MEN den tillater at man kan hente mer ved ? kj?re mer l?ft enn alfabet-kammene opererer med ogs? OM eier/kunde skulle ?nske det, og den fl?der ogs? bedre hvis man putter i st?rre ventiler ogs?, da den st?tter mer hastighet pr. areal i porten.

Som sagt. skal man ikke ha i noe annet enn feks. A eller D kam og andre kammer som knapt beveger seg over 10mm, s? spiller det nesten mindre rolle hvordan det h?let ser ut bare det er tilstrekkelig areal til ? fore det ventilvinduet man har tilgjengelig med luft. Og selvf?lgelig at det ikke sender evt. v?skedr?per (kondensert bensin/wet-flow) en lite gunstig plass.

PS. glemte ? nevne en skarp kant f?r back-cut eller setevinkelen alt etter som (alts? upstream p? ventiltallerkenen, vet ikke hva det kalles i industreien men jeg kaller det undercut av tallerken-ryggen), dreper noen f? CFM riktignok, men gj?r mer enn nok opp for det p? andre vis... F1 har brukt det i ganske lang tid er det meg bekjent Ventilen til h?yre illustrerer prinsippet godt...
"

Translator says..
Possibly "Monkey see monkey do" Like most in the Rob & Duplicate industry ... we KNOW that a port large enough to feed the valve window up to L / D 0.25 will go better than the uncrowded original that doesn't. If you dig larger than that again and anyway if you do not drive more lift than L / D 0.25 then you still have no more cream, just a later port without any special speed, or you have in practice made the 530'n to a 531 ...
 
OK here that thru my favorite on line translator
"Mooleegens "Munkey see-a munkey du" Sum de-a fleste-a i Rub & Doopleecete-a brunsjee... fee FET et in purt sum ir stur nuk teel ? f?de-a fenteelfindooet oopp teel L/D 0.25 feel g? bedre-a inn dee ur?rte-a ooreeginele-a sum ikke-a gj?r det. Grefer mun st?rre-a inn det igjee oog hfertffell hfees mun ikke-a kj?rer mer l?fft inn L/D 0.25 s? her mun furtsett ikke-a nue-a mer fl?de-a, bere-a in letere-a purt utee nue-a s?rleeg hesteeghet, iller mun her i preksees gjurt 530'n oom teel in 531...

Flere-a koonder f?r mun seffff ef ? ?ke-a ereelet oopp deet et tuppee fekteesk fl?der nuk teel et det ir fenteelfindooet sum blur begrenseenga, furdee det foonker bedre-a inn det kleess ooreeginele-a hfur det ikke-a ir fenteelfindooet sum ir truppa. Koondee merker et det ir furskjell i puseetif retneeng kuntra ooreeginel oog unbeffeler s? denne-a jubbee teel neste-a munn sum loorer

Skel det foonke-a inda bedre-a innenffur elffebet-l?fft kun mun lege-a gener?s beck-coot p? fenteelene-a oog gj?re-a setefeenkelee nue-a smelere-a s? innerdeeun p? setefeenkelee ?ker, feks med in feenkel ikstra i seteeennsetsee, fur ? flytte-a fenteelfindooet lengre-a ut s? dette-a blur st?rre-a fur ithfert l?fft... Rydder mun s? lett oopp i brennkemmeret oog gj?r det mer symmetreesk ela bedre-a-brennende-a FEG 2f tupper, s? blur det derteel oogs? it inda bedre-a resooltet, ikke-a bere-a furdee det semteedig fl?der nue-a bedre-a, mee furdee mun utnytter det mun her f?tt inn bedre-a oogs?. Feks. ir dee ooreeginele-a Fulfu l?sneengee med ubrookte-a sqooeesh-fleter i tuppee sum steekker ut oofer grupa i stempelet in durekte-a ?delegende-a effff?re-a, ift. kun mun f? "coostumstempeler" sum gjenspeeeler sqooeesh-fletene-a, mee det igjee ir ikke-a in beellig effff?re-a oog nue-a mun koon helst fureter seg p? it leett mer seree?st NA-bygg hfur mun oogs? feel hulde-a kemmeret nue-a mer kumpekt (p? it fees ir ju ? besere-a seg p? in 530 leett skeefebum i utgungspoonktet hfees ikke-a regler oosf furbyr feks. 16f), oog da ir brennkemmer mud. in bedre-a l?sneeng i de-a eller flestes teelffeller.


That's far easier than the Norwegian..

Try this..It works great or as those Norsk boys spell it greit---but sounds the same.
http://www.tuco.de/home/jschef.htm
 
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