General Category > Quadrajet Carb Talk and Tips

cam selection

<< < (11/18) > >>

tayto:
thanks keith, you have any other specs for it?

tayto:
never mind I did some serious searching and found it in this document:
https://quadrajetparts.com/pdfs/4009B.pdf

tayto:
well, it only took 2 years but i finally have the engine together. had some issues with rocker studs (not enough thread engagment with my roller rockers) so i had to pull them off and have them machined and tapped. machinist took pity on me and allowed me to do them myself on his machine. in exchange I had to do the exact same to a set of camel hump heads for him. Was there all day but it was a good learning experience. I take the engine to the dyno on Monday morning. if successful it will be going back in my truck which is currently waiting for its new drivetrain.

Cliff, I had tried to text you awhile back but the machinist had recommended to advance the cam a degree or 2 to compensate for chain Stretch. dont know if this was the right thing to do or not but I did it and we will see how it turns out. (cam has 106 ICL vs 108 ICL). will keep you posted in dyno results.

tayto:
Well, almost a year later and back on the road. Had no oil getting to my rocker arms last summer which I discovered on a road trip. Limped car home and tore engine apart and went back to machine shop. after some testing we found oil was pouring into the top of the intake valley from the lifter bores. Found GM had drilled some weird counter bore 3/16” into the lifter bore. Block was out if an 87 GMC,had roller lifter provisions bit came with a flat tappet cam. Anyway, having read various things the machine shop decided it would be best to just get a new block. Got engine back in January and started picking away getting it back in. Probably would have had it on the road back in April, but a LOT of screwed up and/or late parts orders. Anyway it's on the road again. BTW, cliff I set the cam to the cam card and DID NOT advance the cam 2*. It actually didn't seem to make any difference on the engine dyno.

Now onto why I posted. Need some help with idle tuning. Carb #17086249 cliff's kit with 73 jets and 50C rods. 355, .034" quench, TBI heads, 213/217 112 LSA cam, on the engine dyno made max power @ 26* total timing. Currently have initial @ 7* (+19 = 26* total). Haven't messed with dist curve yet. Currently making about 15" of vac at idle. My idle screw is turned in so far it is almost coil bound, so i am thinking I should add some idle air bypass? Also the idle is not consistent,it floats. You can actually hear it when sitting at a stop light with the windows down,it will sound ok then the tone changes and drones then goes back to normal and repeats. I did not measure anything when I rebuilt carb 2+ years ago, but everything is STOCK aside from the jets&rods.

tayto:
here's the weird counter bore on my old block if anyone is interested

Navigation

[0] Message Index

[#] Next page

[*] Previous page