Adding 2.02 intake to J heads

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I had my J heads upgraded to 2.02 intake valves. Was told by the machinist that there wouldn't be room for hardened valve seats. So they are not in there.
Was I told wrong?
The port job is nice enough and they flow 246 cfm. intake and 161 cfm. exhaust with the 1.60 exhaust valves.
 
I wouldn't spend a single penny on stock heads. But that's just me.
 
Carman340 said:
I had my J heads upgraded to 2.02 intake valves. Was told by the machinist that there wouldn't be room for hardened valve seats. So they are not in there.
Was I told wrong?
The port job is nice enough and they flow 246 cfm. intake and 161 cfm. exhaust with the 1.60 exhaust valves.
Click to expand...


The hard seat goes under the exhast. Has nothing to do with the intake. I have used 2.100 intakes with a hard seat under the exhaust.

You were either told wrong or you misunderstood.
 
I don't know what I was thinking??? I have a set of 360 heads, 1980-85 596 heads. I plan to install 2.02 valves and had asked (earlier) if the hardened seat area would be completely removed when the machinist cuts the valve seat for the larger valve. But like some of you are saying the 2.02 is an intake valve and the intake seat doesn't require hardening. So as long as I stay with the stock exhaust valve size I'll be OK on the hardened seat issue. I'm building a 318 stroker (390 CI), no high RPM/revving. It will be a torque monster, since I have a 2004R overdrive already installed I won't need high RPMs to putt around the streets or on the highway. I do plan to port the heads so that the 390 can breath but nothing above 5800 RPM. As it is, If I did my math correctly at 5500 RPM and the 2004R overdrive I would be cruising close to 189 MPH with the 3:73 gears I currently have.
No need for a anything over 6K RPM.
treblig
 
If your valves are sunk on the 1.88 seats then by all means go for the 2.02. But if they are in very good shape you would be better off getting new nail head style valves vs. The old tulip valve. The nail head design allows more intake charge to gather behind the valve. I went to 2.02 valves because I'm going to usE them on a 408 stroker. But going from the 1.88 to 2.02 I did notice a slightly better top end but throttle response wasn't as crisp off idle. Just my experience. With a daily street driver I would use the money for something else rather than machine work for 2.02 valves.
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I left my exhaust valves stock size. But when I had the in take seats cut you could definitely see the hardened iron in the seat. But these are also heads from a 78' engine. I was under the impression that after 73 the heads all had hardened seats.
 
Increasing valve size means more curtain area for a given amount of lift. So you'll have more low-lift flow, or "area under the curve." This is like oral sex, too much usually isn't a problem.
 
One thing to consider is that the X head was designed for 2.02 valves and the J head was designed to use the 1.88s. These two heads have very different short turn shapes. Even when the factory installed the 2.02 in the J they didn't fix the problem. The "area under the curve" That the chief mentions makes a huge difference. Make sure you give the short turn a tune up too
 
Scatpacktom said:
One thing to consider is that the X head was designed for 2.02 valves and the J head was designed to use the 1.88s. These two heads have very different short turn shapes. Even when the factory installed the 2.02 in the J they didn't fix the problem. The "area under the curve" That the chief mentions makes a huge difference. Make sure you give the short turn a tune up too
Click to expand...


What you said is true for horsepower right?? If you looking for torque then it wouldn't matter as much...correct??

treblig
 
You can make J heads flow just as good as x heads. There is a lot of porting to be done but it is possible with a little time with a router. Hot rod did a comparison test and they got junkyard 360 heads to flow better than 340 x heads.
 
Treblig said:

What you said is true for horsepower right?? If you looking for torque then it wouldn't matter as much...correct??

treblig
Click to expand...

Engines only make torque, horespower is made by math. You can't have more of one without the other.
 
C130 Chief said:
Engines only make torque, horespower is made by math. You can't have more of one without the other.
Click to expand...

Right on Chief!!!

One of the reasons I mention the torque curve in some of my posts. Tq. x Rpm...:). A lot of people try to build for HP, but don't actually understand how to get there?
 
A bigger hole will flow more air every time.
 
C130 Chief said:
Engines only make torque, horespower is made by math. You can't have more of one without the other.
Click to expand...

Can you give a more definitive answer?? When "Scatpacktom" wrote, "One thing to consider is that the X head was designed for 2.02 valves and the J head was designed to use the 1.88s. These two heads have very different short turn shapes. Even when the factory installed the 2.02 in the J they didn't fix the problem. The "area under the curve" That the chief mentions makes a huge difference. Make sure you give the short turn a tune up too ".

Although porting will tremendously help flow (and horsepower) it's not as critical when you're trying to make torque. My question is based on what I plan to build.... I have a set of 360 heads, 1980-85 596 heads. I plan to install 2.02 valves and had asked (earlier) if the hardened seat area would be completely removed when the machinist cuts the valve seat for the larger valve. But like some of you are saying the 2.02 is an intake valve and the intake seat doesn't require hardening. So as long as I stay with the stock exhaust valve size I'll be OK on the hardened seat issue. I'm building a 318 stroker (390 CI), no high RPM/revving. It will be a torque monster, since I have a 2004R overdrive already installed I won't need high RPMs to putt around the streets or on the highway. I do plan to port the heads so that the 390 can breath but nothing above 5800 RPM. As it is, If I did my math correctly at 5500 RPM and the 2004R overdrive I would be cruising close to 189 MPH with the 3:73 gears I currently have.

Since the 596 heads were made for a 360, if they are ported they should be able to support a 390 with respect to having plenty of torque. If I was planning on making as much horsepower as possible AND turning high RPMs then I would really need better heads, correct???. So my question, "What you said is true for horsepower right?? If you looking for torque then it wouldn't matter as much...correct??", is asking if I will still get plenty of torque in my scenario because horsepower isn't as big a concern since I'm not planning on going above 5800-6000 RPM??

treblig
 
For what it's worth..if you decrease the size of a tube you increase velocity.
"venturi principle" a lot of heads have been ruined by a well intentioned die grinder
 
A venturi increases velocity through restriction. Since when is restriction good?
 
C130 Chief said:
A venturi increases velocity through restriction. Since when is restriction good?
Click to expand...
theoretically increasing port velocity (smaller restrictive ports) should increase lo end performance at the expense of high rpm power
..me,i wouldn't know for sure
 
Is there room for hardened exhaust valve seats when
Making the conversion from 1.88 intake valves to 2.02 intake valves?
 
ir3333 said:
theoretically increasing port velocity (smaller restrictive ports) should increase lo end performance at the expense of high rpm power
..me,i wouldn't know for sure
Click to expand...

No, you got it. A lot is dependent on the build and size of the engine. As well as what you intended to do with it. IMO, not that I'm the sharpest tool in the she's here @ FABO, is in a example of the Edelbrock head as cast. It is not enough head for a well preped small block stroker. The way I see the head as cast is about good for a 360. (Over bores included)

Now a 360 well preped for a street machine could still use the head to be ported and benifit well from it. If the engine is more radical than most average street machine engines. But once you port the head for more power, what happens is (mostly) the RPM band moves up and low end power falls off. The additions of bigger cam higher gears and stall converters are part of the low speed problem.

A stroker of 390+ cubes in a street ride can use it stock and will be a low rpm engine.
Then we port the head out so there's enough head for the stroker.
Ideally you still may need more head for a stroker. Again, this depends on what you want from your engine.

If I was to create a stroker for a cruiser, I would just prep the Edel. Heads and bowl port. Use a 750 carb and 1-3/4 headers. It will make great power and still run hard by virtues of many cubes. Since it is a low rpm engine, big breathing from a large cam duration and lifts are not there so the head doesn't need to support big lifts for big power.

At the advertised flow rates, there plenty for 500HP. But it will take a good bit of cam duration to do it.
 
rumblefish360 said:
No, you got it. A lot is dependent on the build and size of the engine. As well as what you intended to do with it. IMO, not that I'm the sharpest tool in the she's here @ FABO, is in a example of the Edelbrock head as cast. It is not enough head for a well preped small block stroker. The way I see the head as cast is about good for a 360. (Over bores included)

Now a 360 well preped for a street machine could still use the head to be ported and benifit well from it. If the engine is more radical than most average street machine engines. But once you port the head for more power, what happens is (mostly) the RPM band moves up and low end power falls off. The additions of bigger cam higher gears and stall converters are part of the low speed problem.

A stroker of 390+ cubes in a street ride can use it stock and will be a low rpm engine.
Then we port the head out so there's enough head for the stroker.
Ideally you still may need more head for a stroker. Again, this depends on what you want from your engine.

If I was to create a stroker for a cruiser, I would just prep the Edel. Heads and bowl port. Use a 750 carb and 1-3/4 headers. It will make great power and still run hard by virtues of many cubes. Since it is a low rpm engine, big breathing from a large cam duration and lifts are not there so the head doesn't need to support big lifts for big power.

At the advertised flow rates, there plenty for 500HP. But it will take a good bit of cam duration to do it.
Click to expand...

Rumblefish, This is a more direct answer to my question. I figured (and I'm not a genius here) that if a 360 head will support a 360 CI engine then, with a little porting and 2.02 valves the same head would go a long way with respect to a 318/390 stroker IF AND ONLY IF the stroker is built as a street torque machine. I have no plans at all for anything above 5800 -6000 RPM EVER!! Even my torque converter is only a 1800 stall because I plan on having lots of torque early in the RPM range and since I have a 4 speed overdrive auto trans I don't need any high RPMs to go fast (if I want to). At least that was train of thought. I could be wrong but I'm only looking for a healthy street car that's fast off the lights and has great low end (1200-5000RPM).

treblig
 
I went with aerohead cylinder heads they came with 2.02 stainless valves installed for 500 bucks for the pair.
 
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