Fixing over compression on a 2FE (Camshaft analysis?) (1 Viewer)

[ChaserFJ60]

Im getting this clacking noise from my engine when I accelerate in 3rd or 4th gear.

Please note as the title says I have a 2FE. Its the Fuel injection system of an 4.0L FJ62 on a 4.2L FJ60. I have all the electronics from the FJ62, no vacuum advance like the FJ60.

I just replaced my DIZZY o-ring to fix an oil leak, Ive reset the dizzy timing with a timing light to the per-perscribed mark by Toyota. Ive jumped the TE1 and E1 wires when doing the timing and verified that the timing advances when I remove the jumper cable. It used to only knock or ping when I was hauling a load but now its doing it more often. Im not sure what im doing different this time around to get the excessive clacking. When I retard the timing it gets better and Im wondering if this is just one of the things I have to do with a 2FE.

Any input is appreciated.

 

[Seth S]

More advance will often lead to more pinging. What octane fuel are you running and at what elevation? How many miles since you put the 2fe together? Have you checked your valve clearance recently? Also which plugs are you running and have you inspected them recently?

 

[ChaserFJ60]

More advance will often lead to more pinging. What octane fuel are you running and at what elevation? How many miles since you put the 2fe together? Have you checked your valve clearance recently? Also which plugs are you running and have you inspected them recently?

10k miles. cheap Kroger gas at maybe 600ft elevation. If there's anything that should be right on this engine is the valve clearance. Retarding the timing seems to be helping but its >7Degrees. Is this normal to do? I mostly read about people advancing the timing even more not setting it back.

 

[ChaserFJ60]

I just remembered something that may be really important. When I did my 2FE conversion I used the camshaft timing gear from the 2F engine. The 3FE camshaft timing gear is 5 Degrees advanced from the 2F's. Im not sure if the Crankshafts are timed differently or not.

I just retard my timing by maybe 7 degrees and the issue seems to have gone away. Curious on why I have to retard the timing more than stock though.

 

[Godwin]

When you installed the distributor you may have been off by one tooth leading to an overly advanced condition. This is easy to do and the diagram in the FSM for distributor alignment is a bit vague. When you jump the TE1 and E1 ports what is your base timing?

 

[ChaserFJ60]

When you installed the distributor you may have been off by one tooth leading to an overly advanced condition. This is easy to do and the diagram in the FSM for distributor alignment is a bit vague. When you jump the TE1 and E1 ports what is your base timing?

When Initially installing the dizzy I had that issue and had a hell of a time getting it right. Im pretty sure its on right and I can adjust the timing dot directly below the needle.


Right now I have it at maybe 4 degrees from TDC. Im still getting a knock though.

 

[sogafarm]

Try some high octane to see if it quits knocking.

 

[ChaserFJ60]

I'm having the same issue as this guy here Academical : Advance timing on 2F ( 3F ) throughout rev range - https://forum.ih8mud.com/threads/academical-advance-timing-on-2f-3f-throughout-rev-range.858250/ I didnt see a real clear conclusion.

Try some high octane to see if it quits knocking.

I was thinking the same thing. I just got a full tank of 87 octane though so gotta drive it some.

 

[sogafarm]

I'm having the same issue as this guy here Academical : Advance timing on 2F ( 3F ) throughout rev range - https://forum.ih8mud.com/threads/academical-advance-timing-on-2f-3f-throughout-rev-range.858250/ I didnt see a real clear conclusion.


I was thinking the same thing. I just got a full tank of 87 octane though so gotta drive it some.

Get some octane booster.

 

[MoaByte]

Regardless of what your timing light says, retard it until the problem goes away. The higher the octane, the slower the burn. Mine runs great on 91 octane at 4000 ft, and I timed it with 91 in the tank. At sea level, I'd have to retard about 5° or so.

TDC is TDC regardless of valve timing. Align the mark for TDC on the flywheel and the rotor should line straight up to #1 on the dizzy cap (0°)

I'm not sure, but doesn't a 3f head on a 2f increase compression? If so, that would call for high octane fuel and or retarded timing

On my HEI, I installed it 180° off and rearranged the wires so the wires would fit better. Can't do that with 2F dizzy because of the mount. But it runs fine.

 

[ChaserFJ60]

The octane booster didnt do much to help. Im thinking that I didnt jump the TE1 and E1 ports when I did my last ignition timing so im going to try that again if I cant get it to work the correct way. Putting the dot on the mark or advancing more seems to be catastrophic in terms of clacking

 

[ChaserFJ60]

Alright, So I adjusted the timing without jumping the TE1 or E1 ports. I cant hear any bad noises.
When I decelerate I get a popping from my exhaust on the unburned gasses which is what it did before this whole ordeal. As long as the popping isnt hurting anything then im alright with it. I may try and tune the popping out over time.

Whats annoying is when the timing is 7* as the manual wants it to be, It will drive fine for like 5min then start popping. Ive kept the engine at operating temp throughout the entire process.

 

[Seth S]

The compression does increase when you put a 3fe head in a 2f but I don’t think it’s a radical increase. It may be around 9:1 which might be high for this kind of engine design

 

[JDNs78FJ40]

I'm getting this same exact thing. Pinging/knocking in 3rd and 4th when trying to accelerate on any type of incline. Mine is a 2F with a sniper setup. Sounds like I need to turn the distributor a hair clockwise or until the pinging goes away? Will I see any increased power by chance?

 

[ChaserFJ60]

The compression does increase when you put a 3fe head in a 2f but I don’t think it’s a radical increase. It may be around 9:1 which might be high for this kind of engine design

The machine shop planed both the head and the block. I was prefitting everything and without the head gasket the pistons would lift the head. I'm not sure if this is normal or not but I think im gonna run a higher octane from now on.

I'm getting this same exact thing. Pinging/knocking in 3rd and 4th when trying to accelerate on any type of incline. Mine is a 2F with a sniper setup. Sounds like I need to turn the distributor a hair clockwise or until the pinging goes away? Will I see any increased power by chance?

I think some power would come of it, it would make sense to me.

 

[MoaByte]

The machine shop planed both the head and the block. I was prefitting everything and without the head gasket the pistons would lift the head. I'm not sure if this is normal or not but I think im gonna run a higher octane from now on.


I think some power would come of it, it would make sense to me.

You do not want a higher compression than 9:1 for pump gas. Too much compression will cause detonation regardless of timing. Did they CC the head?

 

[MoaByte]

I'm getting this same exact thing. Pinging/knocking in 3rd and 4th when trying to accelerate on any type of incline. Mine is a 2F with a sniper setup. Sounds like I need to turn the distributor a hair clockwise or until the pinging goes away? Will I see any increased power by chance?

The stock 2F dizzy's advance curve is too quick for a desmogged engine. Also the advance limiting pin is plastic and has likely deteriorated adding to the problem. Retard your timing until you can recurve or risk burning a hole in your pistons.

 

[JDNs78FJ40]

The stock 2F dizzy's advance curve is too quick for a desmogged engine. Also the advance limiting pin is plastic and has likely deteriorated adding to the problem. Retard your timing until you can recurve or risk burning a hole in your pistons.

Thanks for the input. I forgot to mention in my original message I have a DUI distributor with livewires. Does this change anything as far as retarding the timing by moving it clockwise? Also, I run 91 octane or non-ethanol fuel at about 4500' above sea level.

 

[MoaByte]

Thanks for the input. I forgot to mention in my original message I have a DUI distributor with livewires. Does this change anything as far as retarding the timing by moving it clockwise? Also, I run 91 octane or non-ethanol fuel at about 4500' above sea level.

You are right. Same boat as me. Yep, retard 1° at a time until it goes away. I have the MAF HEI, I don't know what the advance curve is, or if they are all the same, but it seems to work well for me at 11° idle @ 4000ft.

 

[Seth S]

You do not want a higher compression than 9:1 for pump gas. Too much compression will cause detonation regardless of timing. Did they CC the head?

In an old engine. Modern engines are all up in the 10:1 or high range and run fine on pump gas.

bun an old design like this it’s probably a good idea to not get to crazy