# 326 questions



## danthepontiacman (Jul 5, 2008)

ok i got a tempest with the 250 hp 326 and the 4v 326 had 285 hp with a carter on it, what im wondering is since the valve size in the heads on both veshions is the same then is that increas in poer just in the carb and intake alone or did it have a bette cam? what wasdiffrent between the two? and would puting a Q-jet on instead of a carter ad even more power or be about the same? also if i do a cam and intake swope do you think it will hurt the rest of my engin? it has 45'000 on the rebuild done in the 80's and is a smooth running peppy engin so i dont think its hut but would the stress from adding a 4v be to mch for a 20 year old rebuild?


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## geeteeohguy (Feb 2, 2008)

The cam was different between the two engines. The hi-perf 326 would have an 067 cam instead of an 066 cam, I believe. If I were in your shoes, I'd put in an 068 (tripower) cam, and run the Q-jet if you want to. Be aware that an 068 cam in a 326 will be more lopey than in a 389 or 400. The Carter AFB seems to work really well on the 326, though, and is correct for the car. Age of a rebuild means pretty much nothing, except for dried out gaskets. If you abuse it, it will break, new or old. I rebuilt the 389 in my '65 in 1981, and it still runs great. It does need new valve cover gaskets, though!!


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## danthepontiacman (Jul 5, 2008)

ok thanks thats kinda what i was thinking and i just like the way a Q-jet has smaller mains so if i keep my big foot out of it it should be better for town driveing witch is what i do mostly. the 2-jet thats on it has never gave any trouble but im 24 soon to be 25 and idk how long we will be able to enjoy these cars on americas roads so i want me and my brothers to have some fun with the family car while we can and then i can fix it back original later has long has i dont do nothing drastic. i dont intend to abuse it so it should hold up and ha i hear you on the valve cover gaskets, mine needs some to. its ok i dont mind a little more lope has long has it wont hurt nothing then im happy. thanks alot for the reply, you answered everything i wanted to know. acording to the original hp rateings i should jump from 250hp to 285hp by doing this but see i like the 2:56 rear in the car for:cool mileige so the 4v the other way to go for more response i guess.


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## 66tempestGT (Nov 28, 2009)

the big lopey cam will sacrifice some low end torque. may not feel so peppy with 2.56 but it will sound cool as hell.


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## topfuel67 (Dec 23, 2008)

In the 65 326 the 250hp and 285hp had the same cam. It was different heads. The 250hp had the 8.6:1 low compression heads. The 285 had 10.5 compression heads.


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## danthepontiacman (Jul 5, 2008)

well 2:56 gives me great highway power, at 70 you can hti the gas and the thing just jumps to 80 in a blink of an eye. i normaly run premiume witch here is 93 octan, if i didint change the pistins witch by the way are the original ones and i added the cam it give me 10.5 compreshion, would that be to high for 93 octan? like would i need octan booster even running 93? also would it help at all to install a 4v and not a new cam and keep the lower 9.1 compreshion? and yea 65 the 2v engen had smaller valves but in 66 both used the same heads, diffrent head code bus same casting number and same valve size so im hopeing i can get a tad more power from it. by the way thanks guys, i nkow alot about my car but when in dout ask somebody, im just trying to keep it original has possoble and enjoy it to.


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## 66tempestGT (Nov 28, 2009)

the only way to change the compression is to change the heads or pistons. a cam swap wont change it. the cam only changes how far the valves open and for how long.


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## danthepontiacman (Jul 5, 2008)

well humm, if the heads are the same casting number and the valves are the same size then thay must have used diffrent pistons theme. so it wont change my cr if i use the 068 cam? are the nay concerns i should have about puting that came in my 326? ha i know nothing at allabout cams.


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## 66tempestGT (Nov 28, 2009)

danthepontiacman said:


> well humm, if the heads are the same casting number and the valves are the same size then thay must have used diffrent pistons theme. so it wont change my cr if i use the 068 cam? are the nay concerns i should have about puting that came in my 326? ha i know nothing at allabout cams.


the big lopey cam will sacrifice some low end torque. may not feel so peppy with 2.56 but it will sound cool as hell


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## 66tempestGT (Nov 28, 2009)

66tempestGT said:


> the big lopey cam will sacrifice some low end torque. may not feel so peppy with 2.56 but it will sound cool as hell


dejavu


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## 1970 Lemans (Jul 25, 2009)

danthepontiacman said:


> well humm, if the heads are the same casting number and the valves are the same size then thay must have used diffrent pistons theme. so it wont change my cr if i use the 068 cam? are the nay concerns i should have about puting that came in my 326? ha i know nothing at allabout cams.



I think you have that backward, Dan. It appears to me that for each year that both a 250 or 285 hp 326 was offered, the cams were the same, but the head numbers were different ... I would presume different head volumes.


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## Rukee (Feb 8, 2007)

As far as I know the cam has nothing to do with compression ratio.


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## danthepontiacman (Jul 5, 2008)

well i want to increas torque thruout the rpm rang so what cam do i need?


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## danthepontiacman (Jul 5, 2008)

well its not a easy v8 to find info on, msot folks think there junk. the phs papers i got says this about the 326, time-intake opens 22,closes 67, duration 269. exhaust opens 72, closes 25, duration 277 i have no clue what all that means but where it tells the actual overall head dia. it says intake 1.917 and exhaust 1.637. i ahve no clue what any of that is so any info would be great but regadless of valve size i want to increas my torque at low rpm and mid range. i am tying to retain the same heads and i dont plan on rebuildign the engin just a 4v and a cam. late when i add air i intend to change the rear to a 3:08 like it would of had had it had ac from day one. thank you all for exsplaining this stuff, i nkow almost everything about my car but cam stuff is something i never really got.


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## danthepontiacman (Jul 5, 2008)

by the way a old yearone book shows my car to haveing o94 heads and this site ( Pontiac V8 Cyl Head Info) says this about theme in 66>>>>66 326 094 9782094 Press 1.92(1.88) 1.66(1.60) 68 the 68 was the conbustion chamber size, thats where i got my info so if it was w rong i had no way of knowing.


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## danthepontiacman (Jul 5, 2008)

so based on the info how can i inprove my low end power?


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## 66tempestGT (Nov 28, 2009)

go on and install the 4v carb. as for the cam i would call a cam manufacturer and tell them what you are trying to do. they are the experts. also true dual exhaust will help a little if you dont already have it.


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## danthepontiacman (Jul 5, 2008)

ok thanks, my dad had true duals put on it in the 80s sometime and it did help acoding to him. im not sure if ill go with a carter afb or a Q-jet but are the any concerns with puting the big Q-jet on a stock 2v v8? if thee are ill just put a cater on. i like things being original but the ca has made it 44 years with the 2v i think its ok to change it for a while and have some fun withthe 4v.


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## 66tempestGT (Nov 28, 2009)

if the q-jet is operating properly it will only open as much as the engine demands. both will work fine.


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## danthepontiacman (Jul 5, 2008)

ok thanks for my taste pontiac v8 and a Quadajet just seem to go together.


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## topfuel67 (Dec 23, 2008)

The 66 is pretty close to the 65. The heads are a smaller chamber (about 60cc for the higher hp and 70cc for the lower). I read a great article in a Classic Pontiac mag a few years back about the edelbrok cams. There are 3 to chose from. The lower one is a .42o/.442 lift and around 112 duration. It improves mpg, and power. Matched with the performer intake it has great low end power, perfect highway power and isn't a hog. 

If you're at 8.6-9.1 compression premium fuel is giving you less power, and probably not good on plugs. Octane basically reduces the initial BANG in the combustion. Pinging is caused by the explosion being too harsh on the pistons. High compression motors ping because the blast is too hot, and need higher octane to reduce that initial explosion. 93 octane is probably just right for a 10.5 compression motor. 

If you change to a 4v manifold without the right head and cam combo you won't gain much. The motor needs to be balanced. The cam has to match the intake and the compression. 

Its a good start though to do a nice alum intake with a cool carb, just don't go too extreme on the intake. A lot of guys stick a high rise mani on a stocker and wonder why the car runs like crap.


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## danthepontiacman (Jul 5, 2008)

thanks for the info, im not wanting a hot rod by any means i just would like to give it a tad more power since i intend to keep highway gears in it, i was thinking a stock 67-72 intake and a q-jet with maybe a msd distributor and maybe going from the 2:56 gearing to a 2:73 or 2:78 withever it is gearing, is this a good game plan? or should i change the cam to when i do these things? dang a cam that inproves mpg and powe sounds good, my car gets about 16-17 on the highway and 14-15 in town now, i was hopeing the smaller primarys on the Q-jet would inprove my mpg and the large seconedaries would inprove takeoff when i just crame my foot in it.


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## danthepontiacman (Jul 5, 2008)

oh and i forgot to ask one question, i thalt 93 octane was good fo my car, it calls fo egule in the owners manual but reguler in the 60's was like 94 or 95 octane so i thalt that was helping it. what am i missing?


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## 66tempestGT (Nov 28, 2009)

you wont really see any difference with just the 4V swap, because 99% of the time you are running at part throttle anyway. you will only benefit from the new carb at WOT. the cam swap can improve your power during part throttle operation.


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## danthepontiacman (Jul 5, 2008)

well ok so cam and 4v will go hand in hand when i do it, i got to get the car painted first but i was kinda goign to be buying up parts has i go


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## danthepontiacman (Jul 5, 2008)

oh by the way will the smaller pimeies on the Q-jet help my in town mpg since thay are smaller then the two bores on the 2v?


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## Rukee (Feb 8, 2007)

danthepontiacman said:


> oh by the way will the smaller pimeies on the Q-jet help my in town mpg since thay are smaller then the two bores on the 2v?


yes, as long as you can keep your foot out of it.


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## danthepontiacman (Jul 5, 2008)

oh i will in town:cool


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## topfuel67 (Dec 23, 2008)

The old regular leaded was 88 octane here in CA compared to 87 for our regular unleaded. There is a difference in the way the octane ratings are calculated. Both by state and over time now. The cheapest grade regular unleaded in your state is just right for your motor with stock compression. You'll have more power and better gas milage with the cheapest regular unleaded. If your heads have not been rebuilt with hardened seats you should be running a lead substitute additive. I've talked to several engine builders who say most old cars with out hardened seats have ran fine on regular unleaded without the additives anyways.

For how easy it is to swap the manifold it would be a good start to stick a nice edelbrock performer alum manifold and an edelbrock 600 carb. You could find nice used parts on ebay for about $300-400 and have it done in a few hours. 

The cam new is about $200 with timing chain and gaskets and not much harder than the manifold swap. 

The head swap is the risky one to do. Tearing into the motor leaves a lot of room for issues to come up. I've done a lot of head swaps, some have gone as planned, some have ended up in me tearing the motor apart and being in $3000 over what I planned.


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## danthepontiacman (Jul 5, 2008)

dang well i think ill leave the heads that ae on it on, it runs to good to risk me messing anything up. thats a good price on the came and if i dont put a Q-jet on it i proboly will use a elderbroc, i just dont like the way a carter looks but if i got to put up with that kinda look ill just buy a elderbroc with a electric choke. the engin must be done right, it runs good on reguler and on the 93 octane but we only got one station in town now that dont have ethinal in the gas.


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