building a 350

[79malibu]

update

waiting for the machinist to get done with the short block. still thinking about getting a bigger intake like the 7401 rpm q-jet and looks like with running these big chamber heads that my compresion will end up about 9.3:1 so i think i should be able to get by floging it on cheap stuff.

i still haven't gotten a cam yet. i can't decide between these 3 maybe you guys can help me pick one. with my stall, compresion, and overdrive gears looking to cruise at about 2k rpms for fuel economy but yet give me the power i want would i go with the comp xe 268, comp xe 274, or the lunauti vodoo 268 cam? i need to decide soon so i get 1 shipped in. let me know what you guys think.

 

[79malibu]

parts

anybody?

 

[megaladon6]

i don't know about the lunati cam but the xe274 is a little bit large for a 350. if you are just draggin' it you'll be fine. i'd go with the xe268--fair lope, good power at bottom and top ends. the vortec heads you had problems with-did you get them used and abused or new? i'm a mechanic and i have yet to see a problem with properly installed vortecs. plus a new set of vortecs are $500.00 complete (you will want to put in the cam manufacturers rec. springs)

 

[Silent viewer]

i think 441 heads are 2.02/1.6...... they are basically the same as my 882 heads and i am almost sure they are 2.02/1.6. my motor with flat tops is decent but those heads have low compression, somewhere around like 8.1-1. if you are gonna use them get some domed pistons and get it up to around 9.5-1 and you wil have a high compression and high flow setup. i was going to do that on mine but i got a 350 vortec motor now that has a roller cam and forged pistons so i am building that for the regal now.

 

[79malibu]

350

the vortec heads i went through were used truck cores. yea i've decided that the 274 is too much so now its between the 268's.

 

[79malibu]

350

so i slapped in the comp xe 268 bump stick now i got another mental speedbump. just use 1.5 roller tip magnum rockers or go with 1.6? overkill or am i thinking too hard?

 

[85 Cutlass Brougham]

Honestly, it depends on your overall combo. What heads, valve springs, etc are you running? The thing you need to figure out is if it is going into coil bind or if the rockers are going to hit the retainers. You DEFINITELY want new springs with the XE268 cam as the faster opening and closing ramps will lead to poor valve control if the spring pressures are not high enough. If running the Vortecs, you also need the guided tip rockers. The standard Peformer intake is not optimal in this case, but it will work fine until you can find something better. In my car, the Thermac motor on the air cleaner touches the bottom of the hood. I run a Performer,and a 84 Camaro 305 HO air cleaner base-but had a Edelbrock 600 carb and an air filter spacer ring on it.I recently switched to a Quadrajet which is shorter and fits without the spacer ring. I have not verified the fit with the hood yet as the hood is not yet installed. Oddly, the lid from a Monte Carlo that is on it is not an issue despite being taller than the Camaro lid.

I ran a SIM on my 355 and the XE268 was not worth any more power with the head flow numbers I specified as compared with the XE262, which is why I went with it. I also ran into the same question regarding the rockers. I SIM'd the additional valve lift and found no real gain between the 1.52 and 1.6 ratio rockers. It may be that at this level, the exhaust flow is not high enough to be able to use the additional lift. Additionally, comparing the 2 cams, it may be that the loss of low end cylinder pressure offsets any gains the larger cam represents. The XE262 has a LSA of 114 degrees as compared to the XE268 which has a LSA of 110 degrees if memory serves. A wider LSA traps low RPM cylinder pressure and increases low end torque while a narrower one allows for better filling at a higher RPM at the expense of low RPM torque.

 

[79malibu]

350

just wanna run my enigne to all she has. i got my 441 heads already gutted out and stainless 2.02/1.6 valves in with stiffer springs. my q-jet is already altered and running about 9.25:1 compresion on the block and the extra lift would probably be useless but it make me fell better 😛

would it be better to run an open air cleaner like old school or stock air cleaner with ram air tube lines like what ur running off that maro.

 

[79malibu]

350

just wanna run my enigne to all she has. i got my 441 heads already gutted out and stainless 2.02/1.6 valves in with stiffer springs. my q-jet is already altered and running about 9.25:1 compresion on the block and the extra lift would probably be useless but it make me fell better 😛

would it be better to run an open air cleaner like old school or stock air cleaner with ram air tube lines like what ur running off that maro.

 

[85 Cutlass Brougham]

There are several reasons I ran the Camaro setup. First off, it was free as it was left over from a car I had done from a friend. Second, if set up properly, it is worth some power as compared to an open element design due to lower inlet air temperatures The HO305 (L69) Camaro base inlets by themselves are each larger than the single inlet of a LG4 305. (It's important to note that the LG4 A/C lines and brackets are different than the L69 Camaro pieces. My car uses the correct parts to emulate the Camaro A/C and not the Monte Carlo.) Third, open element setups go through filters fairly quickly, as often as 1500-3000 miles in my experience. The factory setup can go 10-15,000 before it is necessary to change it.While an open element may last longer for some, and a closed element less than I estimated, it is still a valid point that they get dirtier quicker than closed element designs. Fourth, I was going for a factory appearing swap as I am not into cleaning the chrome every week and would rather be driving the thing than detailing the engine or doing maintenance. I also wanted the factory wiring looms that are on the valve covers and didn't want to worry about fuel stains on a nice looking intake manifold-that's why my Edelbrock Performer intake is painted black. On the Performer, I used it because it was better than the 305 intake that was on the car at the time and I found it on a junked Camaro with the carb for $35. It wasn't ideal, but too good to pass up at that price! I even got the tuning book with it as it was in the glovebox. I also plan on Cruise Control as soon as I find a complete setup I can use. The Quadrajet allows me to have the right hookups for the CC and has the proper geometry for the TV cable because I run a TH200-4R.

I think that with the 268 cam, you should eventually get an RPM or RPM airgap-but keep the Quadrajet. When they work right, they are tough to beat on a street car.