hybrid 2.8

[85maro]

You'll have to modify the reluctor on the backside of a rwd 3.4 (not 3400) balancer to produce a signal like a 7X crank signal would. Measure out the notches on a 3.4 crank reluctor with a degree wheel and transfer that to the balancer's reluctor, then weld the other notches shut. I've heard that the dis module can and can't be run without the 24X signal so I'm not sure what's right, but I don't think it's nececary. You don't need the cam sensor. You definately need to seal off the dizzy hole with an oil pump drive from a 3x00 motor.

How high you can push the compression is dependant on what fuel you're using, your cam specs and what you plan on doing. If you're turbocharging later I'd stick around 9.5. If it's n/a then you can get away with a pretty high number with a lopey enough cam. Go to kb-silvolite's website and use their dynamic compression ratio calc to figure out where you need to be. IMO, any higher than 9.5 dynamic compression with pump gas is too much.

[bszopi]

Also if 14.6:1 ratio isn't possible due to detonation/knock what is the highest possible, and or would a higher octane than 87 help allow me to get CR up there?

So wait... You want to run 14.x CR on 87 octane?? No amount of tuning will get you there.

[2.8/3400 1985 Camaro]

So wait... You want to run 14.x CR on 87 octane?? No amount of tuning will get you there.

Yeah, thats what I've been finding, but a more revised calculation is showing 12.8:1 CR which I believe is obtainable, plus all the swap info I've found doesn't mention having to get new pistons to compensate they do suggest metal head gaskets though, probably I'll keep that CR see if I'm getting detonation, if I am I'll try higher octane gas and if I'm still getting it, I'll lower it somehow.
Also you misunderstood, I want to run the highest compression I can on pump gas....preferably on 87, but if 92 octane is enough to compensate I'll keep that CR. Who knows I might not have a problem, I just read somewhere one guy saying CR had to be lowered, then somebody quipped at him saying he knows someone running pump gas just fine with ~12:1 CR. And the ratio's I came up with are static, I believe dynamic is lower, and the one that is usually gone by for this kind of stuff....So time will tell I guess...going to be a while though before I can start building.

[ForcedFirebird]

The 2.8 has flat top pistons, so figure on whatever head you are using as the combustion space. The 3.1 pistons (you will have to use the 3.1 crank) has 11cc dish and the 3.4 has 8cc.

You can run 12.8:1 on pump premium gas, but your tune better be spot on.

Now, if you want to get a reasonable CR and still get the flow you would out of the FWD top end, you can swap in 3100 pistons and use the 3100 gaskets, but again, you will need to use the 3.1/3100 crank.

You can use the TCE external DIS wheel and adapt it to fit on the RWD crank pulley to convert to DIS

[2.8/3400 1985 Camaro]

At the risk of sounding stupid I have no idea what TCE stands for....But it basically bolts onto my crank pulley right? and is on the outside of it instead of the inside, which means I still use a 3400 power steering pump and cover?
And good to know on the CR, in that case I'm definitely keeping it where it is at 12.5:1 or so I think it came out to, call me greedy but I don't want to keep as much of that high compression as I can :P
And the car in question is a project so its not even inspected or registered yet, but once it's ready I plan on getting it inspected and dyno tuned the same day, that or I'll get a tuning chip or software. Hoping for 200+ awp and torque if I keep stock cam, and 235+ if I upgrade the cam.
Btw nice to see some fellow 3rd gen F-body guys around here, all these J and W body types don't seem to know much about the RWD conversion,lol.

[2.8/3400 1985 Camaro]

Edit: Forgot to ask another stupid question, if I'm switching to the EFI system found in the 3400's I will want to shop for spark plugs for that engine yes?

[ForcedFirebird]

Use the RWD timing cover. When you get it mocked up, you will see where it needs to be shaved to clear the FWD coolant neck.

TCE makes the external DIS trigger for the 3500 and later. You can use it and adapt it to fit your RWD.

And you would be surprised at what these guys know

[RedZMonte]

i find it amazing that he is using a truck for autocross.. Cant say i have ever seen that..

S

[dusterbd13]

yeah, not a lot of guys will track and autocross a truck. there are better platforms, but this project started out to prove a point. i told one of my vette customers that you could autocross anything with the right parts, enginuity, driver skill, and time to figure it out. he laughed at that, and said that you needed a sports car to be competitive at anything. so i built my work truck. i consistantly turn better autocross times than him.

after all this discussion on what will need to be changed and one to the 2.8, ive decided that at the end of this season, im going to start hunting for a 3.4 camaro block, as it already has the crank ring on it. im going with 3400 heads, 3400 pistons, and a 3500 efi setup. effictively a 3400 RWD motor. with long tube headers and a small cam.

thanks for all the input and discussion guys.