Street porting a 1.9 big valve head

[Vagos]

sorry here is the pic

[RallyBob]

Originally Posted by Vagos Plus the valves were stock ones.With venturi like shaped.Is it possible to give the stock valves an under cut stem to make them look like chevy valves??here is a pic of a stock opel(from Bamotec valve)next to a chevy one.

Stock Opel valves are two-piece, fusion welded together. The stem is welded to the head of the valve. If they are made too thin here, the head may come apart from the stem of the valve...not good!

Bob

[Vagos]

Realy???Didnt notice that before.It doesnt matter though as my nesxt head will be defenetly a chevy one for my future stroker motor.I have also ported a 2,4 head as BAMOTEC desing as best i could for a friend of mine.And when he tried on his 2,4block on an opel ascona b he was amazed with the results!!!HE said the car has 100% better thant before.Hope this help the german friends here.Cheers

[GTJIM]

Originally Posted by Vagos I have a BAMOTEC head ... But what i DIDNT like on this head is that the ports both the exhaust and the intake wasnt polish and rough as they should be for optimum perfomance they were just left as they were after the porting work.

The ports are supposed to be left ROUGH!

Polished ports 'look' good - and may even flow a little more DRY air on a flow bench - BUT when fuel droplets are added to the flow in the inlet port they produce LESS power and have to be run much richer to compensate for the liquid fuel which spreads out over the polished surface. This also leads to un-mixed lumps of fuel arriving at the valve without the necessary air to burn it!
The fuel film is thought to re-enter the air flow by being re-united with the air flow by being stripped off the little peaks of the rough finish by the boundary air turbulence.

The exhaust port very soon gets coated with a thin layer of carbon - which helps as an insulating layer to stop extra heat being transferred to the coolant through the port wall. A rough surface in the exhaust port helps this carbon film form and stay in place.

So polishing is not only a waste of time - it is detrimental to performance!

[Vagos]

Helpfull info Jim.I have the intake ports rough with 40 grit.And i find that it works fine.But didnt know that polish the exhuast ports has so much difreence over rough ones.Cheers

[yellaopelgt]

Originally Posted by GTJIM The ports are supposed to be left ROUGH! Polished ports 'look' good - and may even flow a little more DRY air on a flow bench - BUT when fuel droplets are added to the flow in the inlet port they produce LESS power and have to be run much richer to compensate for the liquid fuel which spreads out over the polished surface. This also leads to un-mixed lumps of fuel arriving at the valve without the necessary air to burn it! The fuel film is thought to re-enter the air flow by being re-united with the air flow by being stripped off the little peaks of the rough finish by the boundary air turbulence. The exhaust port very soon gets coated with a thin layer of carbon - which helps as an insulating layer to stop extra heat being transferred to the coolant through the port wall. A rough surface in the exhaust port helps this carbon film form and stay in place. So polishing is not only a waste of time - it is detrimental to performance!

Here's a quick question....I understand the "rough" porting in the head area to suspend air/gas mixtures. BUT.....does this also apply to a street ported intake manifold? as-per R-Bobs thread? If the intake base is matched to the carb,and the plenum rounded out a bit and even if the "tent" was in there,does this defeat the purpose of suspension a bit? The intakes shown on that thread appear to be as smooth as a babies bottom.I'm confused....again....
Joe

[RallyBob]

Originally Posted by yellaopelgt Here's a quick question....I understand the "rough" porting in the head area to suspend air/gas mixtures. BUT.....does this also apply to a street ported intake manifold? as-per R-Bobs thread? If the intake base is matched to the carb,and the plenum rounded out a bit and even if the "tent" was in there,does this defeat the purpose of suspension a bit? The intakes shown on that thread appear to be as smooth as a babies bottom.I'm confused....again.... Joe

I can't account for what everyone else is doing to their intakes, but on my own intakes, I leave the intake runners 'as cast'. And the plenum area that is reworked is polished to no finer than a 36 grit finish, so it is rather rough and matches the finish on my intake ports on a ported head.

The plenum 'tent' is rather smooth, but by virtue of the reduction in plenum volume as well as the directional control offered by the 'tent', the air/fuel stays suspended better than with a stock unmodified intake. A stock intake tends to have lower operating vacuum as well as a 'dropped' plenum floor where fuel settles out of the incoming air/fuel mix.

Bob

[Kadett-o-Maniac]

Originally Posted by Vagos sorry here is the pic

Hello neighbour from Greece!

The left valve you have shown is the original from Bamotec, it seemed to be small modified or is it true original?

And the right one is a original or modified Chevy SB valve from which manufacturer is it, Manley or S.I. or somebody else?

The 2.2 valves were fusion welded together, thats right, but he 2.4 valves are one pieced, they were better and stronger for undercut use, but many friends here will use also the 2.2 valves with undercut and it will work, with a 12:1 compression ratio, 7800rpm and 230 HP!

Here are some pics from my new modified 7mm stem valves from Manley, i use the #11229 severe duty for ex. and the #11250 in race series for in.!

What did the cummunity think about the thickness from the head at the ex. valve as related to the heat, will it be warp or pull up in stress situation?

Kyle from Manley means, the large diameter at the in. valve is the critical part, it will be tuliping, because there is more leverage at the outside edge?!

Best regards

[opelnut10]

The intakes look fine, the exhaust valves with the "dimple" in the underside of the head displaces some cc space in the combustion chamber. For maximum compression the flat bottomed valve (like the intake) works better.

[jeff denton]

But look at the extra weight a valve would carry if not for that dished design.
Which do we need more, less weight or more compression ratio? How could you have both? Titanium valves and retainers? Perhaps. I still think Dan has the best setup so far with his small stem Ford valves, beehive springs and tiny retainers.
Other than that, the best answer is to modify the stroke of the crankshaft. You just can't get enough CR with the 1.9's short stroke and a minimal dome on the piston.
Unless of course you want to get away from natural aspiration. Put a little boost, even just a tiny bit, into the picture and then we no longer need most of what we know about high performance engines. Internal parts stay stock and simple, yet power output goes beyond what you could get with a whole lot of fancy parts and hard work.

[opelnut10]

Originally Posted by jeff denton But look at the extra weight a valve would carry if not for that dished design. Which do we need more, less weight or more compression ratio? How could you have both? Titanium valves and retainers? Perhaps. I still think Dan has the best setup so far with his small stem Ford valves, beehive springs and tiny retainers. Other than that, the best answer is to modify the stroke of the crankshaft. You just can't get enough CR with the 1.9's short stroke and a minimal dome on the piston. Unless of course you want to get away from natural aspiration. Put a little boost, even just a tiny bit, into the picture and then we no longer need most of what we know about high performance engines. Internal parts stay stock and simple, yet power output goes beyond what you could get with a whole lot of fancy parts and hard work.

Titanium valves are a no-no on a street engine, they will beat the valve seats into submission in short order. Titanium retainers & locks are a good way to lighten the valve assembly, strong as steel and light as aluminum. Stainless is somewhat lighter than regular valves and they a one piece, anything over 10-10.5 to 1 compression you are not going to be able to run on pump gas anyway. The small stem Ford valves are lighter than the Chevy but more money. Most street cams that produce enough vacuum to idle reasonable and supply enough for the brake booster to work are not going to put out power above 7000-7500RPM, they will turn more RPM's with stronger springs and lighter valves, but they are just making more noise, not HP.

[tekenaar]

Originally Posted by opelnut10 Titanium valves are a no-no on a street engine, they will beat the valve seats into submission in short order. Titanium retainers & locks are a good way to lighten the valve assembly, strong as steel and light as aluminum. Stainless is somewhat lighter than regular valves and they a one piece, anything over 10-10.5 to 1 compression you are not going to be able to run on pump gas anyway. The small stem Ford valves are lighter than the Chevy but more money. Most street cams that produce enough vacuum to idle reasonable and supply enough for the brake booster to work are not going to put out power above 7000-7500RPM, they will turn more RPM's with stronger springs and lighter valves, but they are just making more noise, not HP.

. . . and that's the problem with using absolutes, most, very much like the English language, will have exceptions!

To wit, my 10.6CR 2.2 with 94mm Venolia forged pistons and 2.2I/2.0E valves and RBob cam in a ported 1.9 12-bolt head and fired by '75 disti set to 10° BTDC initial, is at least one exception then . . . it has not run on anything but 87RON regular in my SSD GT since I first fired the engine about three years ago!

[opelnut10]

Originally Posted by tekenaar . . . and that's the problem with using absolutes, most, very much like the English language, will have exceptions! To wit, my 10.6CR 2.2 with 94mm Venolia forged pistons and 2.2I/2.0E valves and RBob cam in a ported 1.9 12-bolt head and fired by '75 disti set to 10° BTDC initial, is at least one exception then . . . it has not run on anything but 87RON regular in my SSD GT since I first fired the engine about three years ago!

Try putting 38 degrees total in it and curve the distributor for it to be all in a 2700RPM and see how well it handles 87 octane. I can't see building a high compression engine and not taking full advantage of those modifications. My engine is a 2.2 with flat top 255 Ford pistons, chevy 1.84/1.50 valves in a 1.9 10 bolt head with a Reed 282 cam and running a Holley 350cfm carb. on a Cannon Manifiold and it will run on 89 octane with a bottle of octane booster added or 93 octane but no 87, congrats on your achievment.

[Hiro]

Originally Posted by Kadett-o-Maniac Hello neighbour from Greece! The left valve you have shown is the original from Bamotec, it seemed to be small modified or is it true original? And the right one is a original or modified Chevy SB valve from which manufacturer is it, Manley or S.I. or somebody else? The 2.2 valves were fusion welded together, thats right, but he 2.4 valves are one pieced, they were better and stronger for undercut use, but many friends here will use also the 2.2 valves with undercut and it will work, with a 12:1 compression ratio, 7800rpm and 230 HP! Here are some pics from my new modified 7mm stem valves from Manley, i use the #11229 severe duty for ex. and the #11250 in race series for in.! What did the cummunity think about the thickness from the head at the ex. valve as related to the heat, will it be warp or pull up in stress situation? Kyle from Manley means, the large diameter at the in. valve is the critical part, it will be tuliping, because there is more leverage at the outside edge?! Best regards

A German racer colleague you probably know (Rene "Driftmaster") recently had problems with such reworked exhaust valves which warped under high load,
So I guess there is a fine limit between very ligh valves & strong enough valve heads.
I will keep my valves the way they are but gain some weight on the valve train using alu lifters from Jörg "Yellowstorm" (you know him also for sure).
Meet you soon @ OHF!
MfG,
Hiro

[RallyBob]

Originally Posted by Hiro A German racer colleague you probably know (Rene "Driftmaster") recently had problems with such reworked exhaust valves which warped under high load,So I guess there is a fine limit between very ligh valves & strong enough valve heads. I will keep my valves the way they are but gain some weight on the valve train using alu lifters from Jörg "Yellowstorm" (you know him also for sure). Meet you soon @ OHF! MfG, Hiro

One thing to always remember, the CIH engines run very high exhaust gas temperatures. A 'normal' racing CIH engine runs EGT's like a turbo engine! Very hard on the valves...

[Hiro]

Originally Posted by RallyBob One thing to always remember, the CIH engines run very high exhaust gas temperatures. A 'normal' racing CIH engine runs EGT's like a turbo engine! Very hard on the valves...

Whao that's very hot,
Another reason for me not to play around too much with my exhaust valve!
Cheers,
Hiro

[RallyBob]

Originally Posted by Hiro Whao that's very hot, Another reason for me not to play around too much with my exhaust valve! Cheers, Hiro

I've measured from 1450° to 1675° F (788°-912° C) degrees in the exhaust ports on a fast road CIH engine. This is the reason I originally started using split-duration camshafts and big inlet valves/small exhaust valves. As a side result the water temperature is lower and there is less fuel consumed.

[wrench459]

Originally Posted by RallyBob I've measured from 1450° to 1675° F (788°-912° C) degrees in the exhaust ports on a fast road CIH engine. This is the reason I originally started using split-duration camshafts and big inlet valves/small exhaust valves. As a side result the water temperature is lower and there is less fuel consumed.

Hee Hee Hee I hear ya Bob
When can we get off of the exhaust temps and look closer to the combustion temps?

[Kadett-o-Maniac]

Originally Posted by Hiro A German racer colleague you probably know (Rene "Driftmaster") recently had problems with such reworked exhaust valves which warped under high load, So I guess there is a fine limit between very ligh valves & strong enough valve heads. I will keep my valves the way they are but gain some weight on the valve train using alu lifters from Jörg "Yellowstorm" (you know him also for sure). Meet you soon @ OHF!

Yes, i know them very good, i have also taken the alu lifters from Jörg and Rene will port and finished my complete engine, the rest, drilling, honing and drilling the valves for oil cooling at the downside from the pistons is now finished by Bamotec!

Jörg has also the 7mm severe duty valves from Manley, but his valves are at 54-56g, a little bit lighter than mine, he uses smaller radius from stem to head, theres the difference and he is also sure, that it will be run!

And Rene has a few other problems, which can caused the damaged ex. valve, i phoned to him and he explain me!

Ok, i know, they will be a little bit to thin on margin/head, but if i will not use them in this performance, i doesnt know, if it will work so, as the old saying goes: No risk-no fun...

The only fear i have is, that they will pull up, thats the worst case and the engine has failure, then is a lot of money "down the river"...

Otherwise, i will order a new set of them and turn in other/thicker measures and hope, that it will work better then!

Best regards

[Hiro]

Originally Posted by Kadett-o-Maniac Yes, i know them very good, i have also taken the alu lifters from Jörg and Rene will port and finished my complete engine, the rest, drilling, honing and drilling the valves for oil cooling at the downside from the pistons is now finished by Bamotec! Jörg has also the 7mm severe duty valves from Manley, but his valves are at 54-56g, a little bit lighter than mine, he uses smaller radius from stem to head, theres the difference and he is also sure, that it will be run! And Rene has a few other problems, which can caused the damaged ex. valve, i phoned to him and he explain me! Ok, i know, they will be a little bit to thin on margin/head, but if i will not use them in this performance, i doesnt know, if it will work so, as the old saying goes: No risk-no fun... The only fear i have is, that they will pull up, thats the worst case and the engine has failure, then is a lot of money "down the river"... Otherwise, i will order a new set of them and turn in other/thicker measures and hope, that it will work better then! Best regards

Hehe Ronny your CIH will be a very good one with Master Bauer's work!
As you say reworking the valve is a risky game & Jörg likes to play this game too,
On the other hand what is the real gain & is it worth the risk?
Lower spring pressure thus lower friction etc that's for sure,
But are you going to rev your engine beyond 9000rpm very often?
My guess is that sticking to 80-90g valves with 105-110kp springs & 38g alu lifters is a reasonable mid-point until about 8500rpm,
Beyond this limit the roller rockers are necessary in any case IMO.
Bob what is your opinion about this valve weight issue?
Hiro

[Kadett-o-Maniac]

Originally Posted by Hiro On the other hand what is the real gain & is it worth the risk? Lower spring pressure thus lower friction etc that's for sure, But are you going to rev your engine beyond 9000rpm very often? My guess is that sticking to 80-90g valves with 105-110kp springs & 38g alu lifters is a reasonable mid-point until about 8500rpm,

Yes, you are right, it isn worth the risk, but anyway is it worth to spend ANY € in a car or a engine, thats the main question...

No, i wouldnt turn over 8000, i think and you are right again, that 80-90g valves with 110kp springs should be enough for this rpm limit!

I hope, the engine will turn very fast with this lighten valve train over 7000 rpm and hope to get the max. power between 7200-7500 and i have a high technical pretension, called "german engineering", its in my blood, i cant change it...

And finally its good for the American steel industry, if i buy my parts at them, not in Germany...

Best regards