Multi Angle Valve Job

[Bolo'sTalonTsi]

I was just wondering, upon head rebuild which should be soon, would a 5 angle valve job be a good idea?

I mean I've had it done on two of my previous cars and there was a feel of difference for the better. Just don't know if there is a difference with DSMs.

 

[bryanwheat]

there was a feel of difference for the better. .

What exactly do you mean by this?

 

[Bolo'sTalonTsi]

More umph as they say. Not a tremendous power gain, but definately a difference.

 

[bryanwheat]

More umph as they say. Not a tremendous power gain, but definately a difference.

I can assure you that you didn't feel any difference due to the multi angle valve job. You might of noticed a power increase from having a freshly rebuilt head, but nothing more. Most modern engines will have a multi angle valve job from the factory. It really is just a smoother transition for the seat and valve. Nothing major.

 

[SpiderGST]

Don't our cars have weird valve angles?

 

[2slow4now]

If I worried about doing anything above stock on a head the place I would start is to port match and deburr the runners. The 5 angle would help with flow but a port match would be more significant. More felt uhhmph? Probably not but it would help the turbo spool quicker so power would come quicker than before.

 

[nickk90]

Don't our cars have weird valve angles?

I think our has a 3 angle form the factory. Not 100% on that though.

 

[2slow4now]

Isn't this about the time Bogus should jump in here?

stock 3 angle

 

[Fehrion_sit]

i agree this is a thread that needs bogus. he's the best man for the job

 

[Bud92gsx]

We have a questions for Justin thread..Why not questions for Bogus

 

[bryanwheat]

I haven't seen bogus on here for a while.

 

[Bolo'sTalonTsi]

I can assure you that you didn't feel any difference due to the multi angle valve job. You might of noticed a power increase from having a freshly rebuilt head, but nothing more. Most modern engines will have a multi angle valve job from the factory. It really is just a smoother transition for the seat and valve. Nothing major.

Soo for a better head performance, other than cams and cam gears of course, I should rather go for the springs, valves, etc.?

Also....yes a newb question....if upgrading to a bigger turbo, along with DSMLink and maybe headstuds, What other major things should I take into careful consideration?

 

[EGLTAWLN]

i am having a head reconditioned at my local shop and they do 5 angle grinds. looks very neat. but really, only one angle actually seals the valve doesn't it? i don't believe they cut the valve to 5 exactly matching angles. why wouldn't a single angle cut work? that way the head would mirror the valve. i don't know.
i will post pictures when i get the head back tomorrow.

i heard if you turn off the lights and look into a mirror and say "bogusSVO" three times, he will sign in and reply...

 

[bryanwheat]

i am having a head reconditioned at my local shop and they do 5 angle grinds. looks very neat. but really, only one angle actually seals the valve doesn't it? i don't believe they cut the valve to 5 exactly matching angles. why wouldn't a single angle cut work? that way the head would mirror the valve. i don't know.
i will post pictures when i get the head back tomorrow.

i heard if you turn off the lights and look into a mirror and say "bogusSVO" three times, he will sign in and reply...

Yes only one angle seals, the other angles are for airflow purposes.

Soo for a better head performance, other than cams and cam gears of course, I should rather go for the springs, valves, etc.?

Also....yes a newb question....if upgrading to a bigger turbo, along with DSMLink and maybe headstuds, What other major things should I take into careful consideration?

You don't really have to do much to a 4g63 head unless you are trying to make big power. Bigger cams will require better springs, but that is about all you really need to do to have a good flowing head.

 

[BogusSVO]

Wow, I did miss a thread.

Bryanwheat, gave a good reply, But Ill go into a bit more detail.

The 4g63 dose come factory with 3 angles.

3 angle valve jobs became factory sometime in the early 70's I would say, maybe a little earlier.

Before that 3 angle valve jobs were for "Race heads"

The common 3 angles fall in these ranges, 15*-30* top cut, 44-45* seat, and a 60*-80* throat

Most are 30*/45*/60*

It gives the air flow a better path to transition around the valve.

Now the width of the seat is a factor also, A narrow seat width will not transfer heat to the valve seat as well, but get the widthy too wide and too much heat is transfered alowing for deposits to build up on the valve head.

A 5 angle is a "mis-term" you still have the 3 angles on the seat, plus the face angle on the valve and a back cut to the valve.

http://www.dsmtuners.com/forums/newbie-forum/341288-why-have-your-valves-back-cut.html

Now a true 5 angle valve job will have 2angles above the seat, the seat and two angles below the seat

Like 15*->30*, 45* seat, 60*->80* and still have the 2 angles on the valve.

Playing around I have done 7 angles with 2 radius, basicly it started on the side of the combustion camber and went down to the valve guide.


Now there is sveral diffrent ways to cut seats, old school is with a stone grinder set up, like B&D, Souix and others, this way cuts one angle at a time, and the stones get grooved and have to be trued, and it it is up to the machinist to set seat width, which can and will vary from seat to seat, and also seat palcement on the valve face. This equipment is still in use today, and is commonly found in machine shops.

Next would be a Nuway system, it is a bit more modern than stones, and it is alum bodies with carbide multi cutter inserts. It still cuts one angle at a time, but gives a smoother seat than the stone. seat width and plaement is still set by the machinist.
This equipment is still in use, and IMHO better than the stone

Next would be the Mira cutter, I want to say this was the first 3 angle cutter out, all 3 angles are cut at once, the angles and the seat width are set in the cutter blade.
The blade fixtures can be found in both live pilot and dead pilot set ups, I perfer a dead pilot style.
Commonly found with Petterson TCM head shops ( Seat and guide machine)

Next is the "Serdi" insert, there is a wide selection to choose from, ranging from 1 angle to 5 angles.
Seat with is set in the blade profile. Custom ones can be made for special custom cuts.
This is the set up I use. Retrofit kits are made to tool older head shops to use these blade inserts.

I would say this set up is common with the better equiped machine shops.

 

[2slow4now]

And there the response of one of the masters of the mechanical stuff!
Well worth the wait.
Someone must have finally looked into a mirror and said bogus 3 times and look at the info that spilled out. Do you need anymore rep points?

I went to a local shop and told them I wanted my seats "serdi" done and they looked at me like uhh what? Off to a different shop I went.

What do you think for the OP for the most bang for the buck power wise to do to his head? A 5 angle or a port match and polish? Do you have any flow numbers comparing the two? We might as well pick your brain while we have you on here.

 

[BogusSVO]

I guess I need to spend some time and mony and set up and flow some DSM heads.

I have done some flow work on 302/5.0 Ford heads, back to back pullsm and did nothing more than back cut the valve, and saw increase in flow of 3-7 CFM

Another time Ford 2.3 SOHC, maching the bowl, and opening the throat of the bowl, for OS valves, no port work show a good increase, that paper work Ill have to dig up.


Just cleaning up the trash in the runners will always help along with the gasket match.
The 4g head flows well, proven over and over by all the builds and diffrent dynos used by the members.

If you decide to home port, just smooth out the flor, and do not change the short turn radius.

Price work from shop to shop and porter to porter can vary drasticly in price. And the quality of the port work will be just as wide as the porting.

But for most on the board, a decent clean up of the runners is all that is really needed.

Tes rep points are always welcomed.