So my current engine is making 189hp (crank) @ 8400rpm. If aiming for 200hp would I benefit more from increased lift or bigger valves. If higher lift I am ready to convert to a shimless setup. My compression ratio could also be bumped a bit.

CURRENT MODIFICATIONS:
Ported head, SilverTop ITB's, FA conrods and pistons, CR ~11,5:1, OMEX 500 DME, limiter @ 9000rpm, 8,5mm lift cams
http://youtu.be/VA_Jw6YosR4?list=UUeSD3 ... MXqzxTsSmg

- Niels

Bigger valves would be my choice as you would be unlikely to make the most of higher lift cams on standard size valves.
If you research "valve curtain area" you will see that there is a formula for valve diameter vs lift.
There is some pretty in depth info on curtain area but the simple guide from well respected Ford engine modification specialists Burton is that valve lift off of the seat should be no more than a quarter of the valve diameter. (http://www.burtonpower.com/)
Standard inlet valve is 29.5mm so the optimum lift according to Burton is 7.375mm

totta crolla wrote:Standard inlet valve is 29.5mm so the optimum lift according to Burton is 7.375mm

Then I am very puzzled by the fact that (almost) all cam companies offer cams with lift in the +8mm range - some, like catcams, even offer +10mm.

No surprise to discover that Toyota appear to have followed the rule above as the standard 4age cams are 7.56mm lift less valve clearance.
Maybe Burton are quoting an 8 valve engine that would have much larger valves to start with ?

std inlet valve is 30.5mm... and I've heard for engines with higher VE, the ratio is on similar scale and increases to about 1/3....


I know I sold you the slugs, and rods.... they are designed to accommodate O/S valves......... a decent O/S valve head should get you there.

I think you are about at the point where bigger valves would probably be smart.
Your list of current mods is too short. What else have you done?
Toda oil pump gear? Or dry sump?
Block reinforcement?
Balanced and blueprinted bottom end?
Exhaust?

If these things haven't been addressed you are already pushing the setup to the ragged edge. Even at your current redline you should be running an oil pump gear. If you plan on raising it further (which you probably will want to in order to make much more power) you will probably seriously want to consider going dry sump if you aren't already. I can get the Toda gears and also some Dry sump kits.
Shim under would be a good idea at this point for sure.

What thickness HG are you running?
What pistons are you running?
Would you be going with new pistons or just trying to raise compression through HG and shave?
11.5:1 is already on the low side for your setup. I'd definitely be aiming a good bit higher than that.

oldeskewltoy wrote:std inlet valve is 30.5mm... and I've heard for engines with higher VE, the ratio is on similar scale and increases to about 1/3....


I know I sold you the slugs, and rods.... they are designed to accommodate O/S valves......... a decent O/S valve head should get you there.

Sorry if I got that wrong, to be honest I have not measured the valves and I got lazy and looked it up at........ Billzilla........

Here is the full build list.

Smallport, silvertop ITB's, OMEX 500, TRD 0,5 headgasket, FA conrods + pistons (supplied by Dan and milled to lower CR), std oil pump and valvetrain (see cam below), Martelius R1 header and exhaust, head ported and flowed (as an experiment by a friend that was building his own flow bench), engine balanced to 9500rpm.

The cams was bought second hand as 288/8,5 but I measured them myself and got below numbers. I dont know the brand and cannot find specs on them anywhere. Trying to match these measurements against some catcams does not add up @ 1,2mm so probably not catcams.

Inlet
@0,2mm - 302grader
@1,2mm - 212grader

Exhaust
@0,2mm - 296grader
@1,2mm - 210grader

The 9000rpm lmiter will not be increased. If I also chose to go with higher lift I will convert to under-shim setup. Head and block has not been shaved so how much CR can I gain from that? Which brand of valves would you go with? Supertech, Ferrea?

My cams - I would love if someone could find the specs on these!

given that i now will get bigger valves, run a shimless setup and can increase the CR by shaving the head what cams will you guys recommend? yoshimitsuspeed mentioned kelford being a really good cam - what about catcams that are easy to source in europe?

Why not try the cams you already have with the large valves ?
Those cams certainly appear to produce the goods !
Using lift of more than 9.5mm will require that a relief is cut out of the head for each of the lobes.

totta crolla wrote:Why not try the cams you already have with the large valves ?
Those cams certainly appear to produce the goods !
Using lift of more than 9.5mm will require that a relief is cut out of the head for each of the lobes.

I will not be doing this build myself so not going all-in first time will double the labour and dyno cost. it would however be very interesting to see the effect of the bigger valves only.

totta crolla wrote:Why not try the cams you already have with the large valves ?
Those cams certainly appear to produce the goods !
Using lift of more than 9.5mm will require that a relief is cut out of the head for each of the lobes.

I'm going to second that.

for the valves... there are a few manufacturers... Supertech advertises a lot, but SI and Ferrea both offer 2mm O/S 4AG valves as well. If you keep lifts under 10.5, you can use Toda valve springs instead of double springs.... which requires special guides... seals... springs... and retainers(big cash outlay).

Once you go O/S, you will want to source either a Tomei, or Toda exhaust gasket... because 33mm outlet is a bit small for the O/S valves, Tomei and Toda can accommodate a 38mm exhaust outlet.

Since you are often close to 9000 I'd also recommend using the Toda oil pump gears

@totta crolla
Hey

I cannot reply your message because is am not "seasoned" enough in here (however stupid that is)...so please send me an email: harkes@gmail.com

oldeskewltoy wrote:for the valves... there are a few manufacturers... Supertech advertises a lot, but SI and Ferrea both offer 2mm O/S 4AG valves as well. If you keep lifts under 10.5, you can use Toda valve springs instead of double springs.... which requires special guides... seals... springs... and retainers(big cash outlay).

Once you go O/S, you will want to source either a Tomei, or Toda exhaust gasket... because 33mm outlet is a bit small for the O/S valves, Tomei and Toda can accommodate a 38mm exhaust outlet.

Since you are often close to 9000 I'd also recommend using the Toda oil pump gears

So Dan...you don't have any particular preference for valves? I guess you are implying that I need to enlarge the exhaust ports since I need a bigger exhaust gasket, but then my exhaust will not fit..? I thought bigger valves only needed a rework of the valve seats?

I was scouting for a calculator that can estimate the gains of bigger valves and higher lift. Came across this one (http://www.wallaceracing.com/hp-valve-size.php)and punched in my numbers (30.5 - 2 - 4) which gives 194hp - 5hp off my own numbers. So in the case this calculator is not too far off I would be able to see 214hp with 32mm valves!

npharkes wrote:

oldeskewltoy wrote:for the valves... there are a few manufacturers... Supertech advertises a lot, but SI and Ferrea both offer 2mm O/S 4AG valves as well. If you keep lifts under 10.5, you can use Toda valve springs instead of double springs.... which requires special guides... seals... springs... and retainers(big cash outlay).

Once you go O/S, you will want to source either a Tomei, or Toda exhaust gasket... because 33mm outlet is a bit small for the O/S valves, Tomei and Toda can accommodate a 38mm exhaust outlet.

Since you are often close to 9000 I'd also recommend using the Toda oil pump gears

So Dan...you don't have any particular preference for valves? I guess you are implying that I need to enlarge the exhaust ports since I need a bigger exhaust gasket, but then my exhaust will not fit..? I thought bigger valves only needed a rework of the valve seats?

I was scouting for a calculator that can estimate the gains of bigger valves and higher lift. Came across this one (http://www.wallaceracing.com/hp-valve-size.php)and punched in my numbers (30.5 - 2 - 4) which gives 194hp - 5hp off my own numbers. So in the case this calculator is not too far off I would be able to see 214hp with 32mm valves!

1) I've built one O/S valve head....it came with Supertech valves..... I know Loynings uses Ferrea quite a bit(not exclusively)... BUT I believe they re-shape the valves back to what they have found works for them.



Here is a chart burdickjp drew up a few years ago. He tested a 1mm O/S valve exhaust without further porting... and he used a stock exhaust... he then overlayed my information... as you can see the O/S valve has great initial filling, but hits a wall fast @ 5mm lift, where you can see my ported stock valve port work is still going up well past 10mm of lift.

What is the ID of your header/manifold primaries??

So whats the conclusion here? If my cylinder will fill faster I should also trap more air and get a bigger bang - right? So money aside - this is good. Can the area under the graph be used to estimate hp gain?

Not sure this is what you mean, but:
Silvertop ID 42mm
Martelius R1 41,5mm

npharkes wrote:So whats the conclusion here? If my cylinder will fill faster I should also trap more air and get a bigger bang - right? So money aside - this is good. Can the area under the graph be used to estimate hp gain?

Not sure this is what you mean, but:
Silvertop ID 42mm
Martelius R1 41,5mm

First point here... from memory this chart was a 1mm O/S valve... not a 2mm. 1mm O/S valve typically can be fitted on to the existing valve seats, 2mm O/S valves typically need the old valve seats removed, and new seats pressed in. In OST-017 the client requested 2mm O/S valves. The view below shows the intake bowls ported out to the new valve seats, while the exhaust side bowls are not yet enlarged. You can tell these are new seats because both seats on the right - one intake, one exhaust - have you to be machined to fit a valve



The conclusion are... the O/S valve WILL help... but make sure the exhaust port can flow the volume coming from the valves. The Martelius R1 has 41.5mm internal diameter? If that is accurate, then you can push the port outlet to as far as 38mm. If the Martelius is 41.5 outer diameter, then the inside is 38, and so you want about 35 at the port outlet

I am having a very hard time finding some valve seats for those oversized valves.

The original ones from TRD are discontinued...
http://www.trdparts.jp/english/parts_engine-4a-g16.html

What to do?

npharkes wrote:I am having a very hard time finding some valve seats for those oversized valves.

The original ones from TRD are discontinued...
http://www.trdparts.jp/english/parts_engine-4a-g16.html

What to do?

search for "valve seats"???

http://www.martinwellsco.com/index.php/valve-seats/

[/quote]

search for "valve seats"???

http://www.martinwellsco.com/index.php/valve-seats/[/quote]

That's very embarrassing...I did exactly that (using bing.com - since we don't have access to google from China) and got very little - thanks Dan.

Answer from Supertech: "You should be able to modify your current seats." Not very confidence inspirering...so Ill get some new ones.

BTW: My head is flowing 190CFM @ 9mm lift and 20inch water. Don't know if that is really good but theoretically that should be enough for ~213hp.