4afe Engine Mods

[quattro]

Hi guys... need help on my 4afe.

 

Mods as follows:

 

272 cams intake exhaust

ported and polished head - shaved 50,000 of a mm.

toms ecu - no revlimit

4-1 exhaust manifold - equal lenght - stainless

 

problem is... will there any valve or valve springs I can use to replace factory ones.

or will any valve from any other engine fit in 4afe head? I'm having problems in 7500 rpm... valve float.

 

can you help with this.

 

o and I finally made a mating manifold to fit a 20valves ITB to 4afe head. I hope emanage can help me tune the engine. hehe.

any suggestions? thanks.

[beerhead]

Hey, pull out a valve spring and take it to a engine machine shop, they'll have a catalog and you'll be able to find matching springs. In the past I've shimmed valve springs to increase tension, but with a bucket motor its very difficult to know if you're going to bind the valve spring and destroy it. You'll have to find out if emanage can let you go to a TPS tune. Map on quads is tedious to tune, and requires a vaccum canister and heaps of mucking around to make it run.

[Sam_Q]

is it an early or late 4afe head?

 

pic of engine or manifold?

 

are you from Sth Africa?

[quattro]

is it an early or late 4afe head?

 

pic of engine or manifold?

 

are you from Sth Africa?

 

 

nope. right now I'm in Canada.

 

 

http://s43.photobucket.com/albums/e397/_Ta...urrent=4afe.flv

[quattro]

Hey, pull out a valve spring and take it to a engine machine shop, they'll have a catalog and you'll be able to find matching springs. In the past I've shimmed valve springs to increase tension, but with a bucket motor its very difficult to know if you're going to bind the valve spring and destroy it. You'll have to find out if emanage can let you go to a TPS tune. Map on quads is tedious to tune, and requires a vaccum canister and heaps of mucking around to make it run.

 

 

ic. good idea. hehe. havnt thought of that. ill try that sometime.

[Hiro Protagonist]

 

nope. right now I'm in Canada.

 

 

http://s43.photobucket.com/albums/e397/_Ta...urrent=4afe.flv

 

 

Thats a late model head, you can tell because it has the same cam covers as the 7AFE. They also have the injectors mounted in the manifold. Early 4AFEs look similar to 4AFCs, and has the injectors in the head.

[Sam_Q]

ok this is a very good thing, it means you have the good head. For the valve springs they are the same outside dimentions as 4age springs, and I can only assume that the 4age springs have a heavier rate stock. However because the 4/7afe head uses 31mm valves vs the 29.5mm of the 4age I personally decided to go heavier again with my 7afe head and I bought some 4age 16V springs. I am only going to use them on the intake though as I don't see the point of heavier than normal 4age springs on that side.

[Sam_Q]

oh I also forgot to say you can run some 20v pistons with valve pockets cut into them and while your at it check your piston to head clearence, on some of these engines that gap is quite big which is quite a bad thing. There is no real need to change valves unless your trying to do something odd like me and run more agressive spec cams without welding them by using longer valves. How did you adapt the 20v manifold to the head? did you make sure that there isnt a sudden change in angle between the head and the intake? Who did your cams?

[quattro]

oh I also forgot to say you can run some 20v pistons with valve pockets cut into them and while your at it check your piston to head clearence, on some of these engines that gap is quite big which is quite a bad thing. There is no real need to change valves unless your trying to do something odd like me and run more agressive spec cams without welding them by using longer valves. How did you adapt the 20v manifold to the head? did you make sure that there isnt a sudden change in angle between the head and the intake? Who did your cams?

 

I used honda ctr pistons, modified pins to fit.

 

wow nice info on the valve springs. Cams are custom made, came from New Zealand (well thats what the seller said when I bought it). the intake is at the same angle as runners inside of the head.basically extending the line.

[quattro]

ok this is a very good thing, it means you have the good head. For the valve springs they are the same outside dimentions as 4age springs, and I can only assume that the 4age springs have a heavier rate stock. However because the 4/7afe head uses 31mm valves vs the 29.5mm of the 4age I personally decided to go heavier again with my 7afe head and I bought some 4age 16V springs. I am only going to use them on the intake though as I don't see the point of heavier than normal 4age springs on that side.

 

can you explain further. hehe. does that mean I can use a stock 4age valve spring in a 4afe head? thats good to hear. or can I use a 20v valve springs? I found a Toda set for 20v 4age. if so please enlighten me.

 

Thanks

[Sam_Q]

20v springs are no good because they are a really small diameter.

 

So your choices are a normal 4age spring which fits straight in or anything else thats meant to suit a 4age like the trd set. The 4age spring fits perfectly under the 4afe valve spring retainer so no modifications are required. Its only because my head was going to see 9000RPM on a regular basis that I chose to fit normal 4age springs for the exhuast side and trd 4age springs to the intake side.

 

If your manifold lines up so that its one continous line from the ports to the throttles then thats a great thing because even a stock 20v has a bit of an angle change from where the manifold bolts to the head. This causes a flow loss of 10% if someones flow bench results are to be believed.

 

So how agressive was the porting on your intake side? If it was only a light cleanup then it might be pay to get it ported further, the inside diameter of each runner is only 24.5mm in original form which is undersized by a far way for higher RPM use.

[quattro]

20v springs are no good because they are a really small diameter.

 

So your choices are a normal 4age spring which fits straight in or anything else thats meant to suit a 4age like the trd set. The 4age spring fits perfectly under the 4afe valve spring retainer so no modifications are required. Its only because my head was going to see 9000RPM on a regular basis that I chose to fit normal 4age springs for the exhuast side and trd 4age springs to the intake side.

 

If your manifold lines up so that its one continous line from the ports to the throttles then thats a great thing because even a stock 20v has a bit of an angle change from where the manifold bolts to the head. This causes a flow loss of 10% if someones flow bench results are to be believed.

 

So how agressive was the porting on your intake side? If it was only a light cleanup then it might be pay to get it ported further, the inside diameter of each runner is only 24.5mm in original form which is undersized by a far way for higher RPM use.

 

 

matched ported with the intake manifold. I'm not sure about the exact number i had to send it to the machine shop and just said to match it with the intake manifold.

oh.. by the way... what ECU will you use?

[Sam_Q]

unfortunetly matching the ports isnt enough, the easy way to tell is if you can open the throttles and you can see all of the insides of each intake runner right near the valve. Here is what I initially had planned:

 

 

I have a Wolf V4 waiting to be used.

Edited November 5, 2008 by Sam_Q

[quattro]

unfortunetly matching the ports isnt enough, the easy way to tell is if you can open the throttles and you can see all of the insides of each intake runner right near the valve. Here is what I initially had planned:

 

I have a Wolf V4 waiting to be used.

 

wow... I have to be honest.. I just know the flow so I just made it as straight as possible. Thank you for the inputs. and wow I can't afford wolf ECU. I'm looking at megasquirt right now. probly I'll still have to do research more on that.

 

I'm doing my car to be an everyday car that goes on weekend races.

[quattro]

Sam Q,

 

Do you know if the 4ag valves fit in a F head? I'm sourcing out parts for the F head.

 

Thanks