Timing/cam Issues?

[pissedoff92]

My buddy has an 87 with the HO motor in it. he just put gt40 heads, some headers and a new cam in it. The cam is a comp cams 31-601-5. I cant get the timing right to save my life. I think im a tooth off on the distibuter but my main concern is what would the firing order for this cam be? would it be 351W/ HO firing order or the old school 289/302 firing order? As of now it runs on the H.O order and ive got it set at 10deg with the spout connector out and it pops and misses like crazy. it will only run with ur foot in it. it wont idle at all.

 

[88LX5.Oh]

302 HO's used the 351W firing order. I googled this cam you said you had. Came up as flat tappet. Our cars have roller cams.

 

[a91what]

When you buy a new cam it should come with a cam card giving you all the information you need to set firing order. the card also has all the characteristics of the cam, i agree with 88lx5.oh, the cam you listed is flat tappet. our cars are roller motors.. TDC number one and drop the dizzy again... use a pos. stop tool advanced carries it, or if your really careful you can use a screw driver. BUT i would figure the cam issue out first.. you could probably google it... :search:

 

[pissedoff92]

Whats a positive stop tool? By the way I got it figured out. it used the old sbf firing order opposed to the ho/351 firing order. it is a flat tappet cam, i didnt know that at the time like I said its a friends car. He put new lifters and pushrods in it. why hes want to do that is beyond me.

 

[88LX5.Oh]

Tell him to junk that cam and go back roller.

 

[a91what]

The reason all newer vehicles have roller cams and lifters is for one reason. efficient... the extra stress exerted on the valve train is needless, he basically just took one huge step back..

 

[88LX5.Oh]

And not to mention, the specs on that cam are almost equivalent to a FRPP B303. And we all know how the letter cams are...

 

[NIKwoaC]

1. You can't change the firing order of an EFI 302.
2. The "one tooth off" distributor thing is a myth. If the rotor is pointing at the #1 terminal when the #1 cylinder is at TDC on the compression stroke, the distributor is installed correctly. Simple as that.

Is he running roller lifters or flat tappet lifters on that cam? It sounds to me like your buddy has this thing FUBAR.

 

[jsw81]

And not to mention, the specs on that cam are almost equivalent to a FRPP B303. And we all know how the letter cams are...

all hail B cam.

 

[88LX5.Oh]

all hail B cam.

I honestly don't know if I like it or not in my car. I've only driven the car twice. But so many people on here complain "oh it's old technology and it sucks"

 

[a91what]

I run the enfamous E cam. I personally love it, big long torque curve and she breaks free when i hit 3k.

 

[jsw81]

I honestly don't know if I like it or not in my car. I've only driven the car twice. But so many people on here complain "oh it's old technology and it sucks"

sounds badass at idle at least!

 

[pissedoff92]

Why cant you change the firing order on an efi motor? He doesnt have the money to fund a new cam and lifters. Let alone pull the motor again to install one. Yes he changed the lifters to flat tappet. And I totally agree with you guys he made a huge mistake going back to flat tappet. but im just tryin to help the kid out.

 

[NIKwoaC]

Why cant you change the firing order on an efi motor? He doesnt have the money to fund a new cam and lifters. Let alone pull the motor again to install one. Yes he changed the lifters to flat tappet. And I totally agree with you guys he made a huge mistake going back to flat tappet. but im just tryin to help the kid out.

Because even if you switch around the plug wires, the injectors will continue to pulse in the old firing order. It is possible to rewire the injector harness to get them to fire in the new firing order, but at that point you're creating a mess to fix a mess. Honestly, he should stick the stock cam back in it and chalk it up to a learning experience, or possibly find a cheap used roller cam and plug it in there.

 

[pissedoff92]

makes sense. thanks a bunch guys