6.6L 400 needs MORE AIR

i am running almost completly modified engine i need to find a set of cast heads that flow better and have bigger vavles so i can go faster. i am currently running factory heads from 79 that have been decked .020 in. sitting on a block with .010 in deck i NEED MORE AIR. Also does anybody know how hard it would be to mount and install a turbo off of a 82 cummins turbo diesel 18-wheeler i have two.:biggrin: i know i will need one hell of a blow off vavle.

yuck your running smogger heads.If your going with a set of stock heads,get a set of pre-1972 heads,cause after 1972,pontiac heads lost a lot of power.In 1970 they put a set of heads on the judges,that promised 400HP.In 1973 all pontiac had was a set of 350HP range heads.

What cam duration do you have?

i have been told that the 70 judge head was what i need but i can't find them. my engine trying to get air through those vavles is like trying to get a cruise ship to turn around in a kids swimming pool.

i have a crane 282/282 duration and 484in lift energizer cam with energizer 1.65 in lift roller rockers

i also have the energizer push rods and rhoads lifters

bigger valves dont always make your car go faster.Bigger valves are slower off the line,but make up for it later on down the road.The compression of the bigger valve heads is lower,so you sacrifice compression for flow characteristics.You will not notice a major power increase with bigger valves,unless you mill them down to get your compression back again.

I just talked my boss out of a set of 1970 GTO judge heads.they need totally reworked.But they will make a nice addition to my 400PO wich im putting in a 3200 pound car

i plan to completly rework the heads that way i can tailor them to my motors blue printing. it is not quick off the line or in the quarter it is more adapt to long high speed runs or around a big track

i just need to find them and it will be all good

According to my boss you cant just find a set of 70' judge heads.Thats why hes makin me pay 300 for them(wich is what i payed for my big valve SBC heads).

have you dyno'd your 400?

I have tried e-mailing and call from east coast to west coast north to south to try to find these things at salvage parts and junk yards all over. I recently found out that my uncle has some but there on his 1970 factory grand prix

it dynoed at 502 hp at the flywheel at 6800 rpm peak

holy crap.I have a 1972 block,with flat forged pistons,a 268 duration(if not bigger) cam,and a set of 70' gto judge heads.What kind of power do you think that will make.It has less than 30 thousand miles on the block,and im getting the heads reworked,and putting extra clutches in the 400 trans

what lift does the cam have? you will probably be around 450-475 depending on intake, carb, stroke and crank. i am running hypereutectic domes with a little longer than stock rods with custom cut forged crank

im not sure what the cam lift is,all i remember is the duration of the cam i ordered for it.I built the motor a few years back.I had the heads milled down pretty far,cause they were a little off.And it had to be bored out 30 over.
Back when i built it,i had the motor and the heads redone by a local trusted machine shop.So i never even looked at the numbers on the heads.But i do know the machine shop called me and told me for them to seal up good i would have to mill them down to maximum.I believe i even got charged extra for custom valve cut-outs.Its kinda confising trying to remember all this crap.

it gets real technical when you do the blueprinting and all the math invovled. especially when i sucked at math when i was in school. any ways you should be good for at least 450hp

my block is not stock either i have had extensive machining, clearancing, straightening and looking over to make it straight level and a solid platform. other than that all i will say is i can slide my big size 16 foot throught the cylinder and (besides not being able to move my leg) wear it around my ankle

i still need to know about the turbo

turbo?

i have two twin turbos off an old '82 18-wheeler cummins engine. i am trying to find out if i can get them to work with my engine or at least one, because they are rated at like 60 p.s.i. boost

I think putting those turbos on there would be a mistake...the cost and time in making it work added to the fact that that much boost will blow the heads off the engine make for an undesirable project in my opinion.

i would like to run some sort of forced induction. its either one of those turbos or a 14-71 blower. i was leanning more toward the turbo so i could keep the shaker style hood that i love, but i have already had to solid mount the scoop to the hood do to clearance problems with my intake. money on this part of the project is no option. could i get blow off vavles and waste gates to cut back enough of the boost that i won't blow my heads off?

It looks like this thread has gotten a bit off track. I can shed light on the heads and cam issues.
The '70 GTO had two "Ram Air" engines available. The 366 HP version of the 400 (base engine for "The Judge") called Ram Air III, and the 370 HP version called Ram Air IV. There was also a 455 HO available in '70s.
The Ram Air III head is casting number 12 (found on the center exhaust ports). It has 2.11" intake valves, 1.77" exhaust valves, 72 CC (nominal) chambers, and a "D-port" exhaust. These heads have become prizes among the collector and restoration crowds. If you find a pair in decent shape, expect to pay between $500 and $1K.
The 614 is another matter. This is the "Ram Air" head everyone talks about. They were on the Ram Air IV engine ONLY. While they share chamber and valve size, that's where the similarities end. The chamber, while 72 CCs, is shaped a bit different, and could be considered a "compact wedge". The intake valves are "tuliped" to improve high lift flow. All the valves are about .200" longer than any of the other Pontiac heads. This allows for a taller spring to accomidate more lift. The cam that came in these engines was .520" lift, as opposed to the .407" lift in the other Pontiac performance engines. If you're actually able to find a pair of these in decent shape, expect to pay in excess of $2K for them. Don't hold your breath...
The 6Xs found on that late T/A are by no means, smogger junk. Pontiac's approach to emmission controls was a bit different than most other American companies at the time. The 6X has a very good intake port, and the same 2.11 valve. The exhaust port is okay, but can be made much better by installing the larger 1.77" valve (1.66" is standard). The biggest problem is with compression. The chamber for the HO 400 is 92 CCs. This yields a low 8.8:1 compression. Milling it .060" will get you to 9.5:1. This is the head of choice with today's 455/iron head combination.

I'm curious about the statements about the blocks and forged cranks. 400 blocks are virtually all the same, including the Ram Air stuff. There was one deviation, and that was Ram Air V (tunnel port), which was never installed in production cars.
There were no production forged cranks, either. The only aftermarket cranks today are either cast steel (Eagle) or a custom billet (Crower, Moldex, etc.). If you're lucky enough to have one of the early Super Duty 389 cranks ('60, '61), great! But rare as hen's teeth!
Rather than listening to anyone that claims they know Pontiacs (whoever said "Judge" heads were great is NOT one of them...), buy Jim Hand's book "How to Build Max-performance Pontiac V8s". It has been in print for less than 6 mos. Very current and accurate information. No myth or superstition there!

As Pontiac bigot, I'm proud to say: "We're baaaackkk...!" There are more Pontiacs being built for performance and racing today than there were 20 yars ago. Not bad for an engine family out of production over 25 years! The reason is simple. With the advent of NMCA and other muscle car sanctioning bodies, GTOs are at the top of the list in popularity (they outsold their nearest competitors by more than 2:1 in the '60s and early '70s). Since most Pontiac people aren't willing to put a Chevy engine in their car, they needed good parts to compete. The aftermarket has answered the call. There are now at least 5 different companies making aluminum racing heads, three making blocks (REAL ones...), a ton of modern cam and valve train parts, etc. etc. etc.
Not long ago, Jim Butler Performance published findings on their newest monster. A 494 CID Pontiac making 2,880 HP and immeasurable torque! That rivals all but the highest of budget big block Chevy OR MOPAR (not including Top Fuel, of course).
Kaufmann Racing also has a 2,400-pus HP blown/alcohol door slammer that runs in the high 6s. And these are TRUE "traditional" (we call it the Injun) Pontiac V8s, not big block Chevys with Pontiac-designed heads (ala "Big Chief").

Off soapbox now...

Actually i thought it just got on topic...Since now he left hooked with a 30psi turbo and blower talk.Thats what you supposed to be hearing,not talk of putting some of those smogger 250 hp junk smogger heads on top of a potential torque monster.Those post 72' heads gave pontiac a bad name.Get everybody all ready for the good stuff,then chop it down to grocery gettin status.

You want a good pontiac head with some collector value?get you some of the heads off an old tri-power,or a set of 67' high compression heads built around a quadra-jet.

hey some of the ram air IV's with a 4 speed standard option came with a stock set of 67cc combustion chamber oval port heads.i found a possible pair hiding in tulsa oklahoma.But when i asked to buy them,when he shot me the price u bet i hung up the phone a little on the pale side.That guys crazy if he thinks im going to pay 3 grand for a set of heads i wouldnt bolt on at that price.Hell for 300 bucks i can get the judge heads,for another 300 bucks i can put longer valves,stiffer springs,and mill them to god knows what compression.
where im unfamiliar with all the casting numbers and each years configuration,all i know is if i take these heads and this block over to my machinist it will be the last time this motor ever runs right on pump gas

i just have to be careful not to twist my car body in half,till i can come up with a tube chassis.

thanks for all the information on the heads folks. I have came to the conclusion that my intake valves are ok but i may need longer stems. my exhaust valves are to small but if i have them opened up to 1.77 or a little bigger with longer stems they will work fine. But my main concern is that of the clearance, my heads have been taken down .020 and the block down .010 on drivers side and .011 on passenger side to straighten block. and with the 1.65 roller rocker and .484'' lift cam will they contact on no. and still looking for info on the forced induction question.

to mrpbody's comments about the ram air V (tunnel Port). This engine was not a production engine. I am not sure what engine this is because GM has no record of it ever being built for the street. I they have found out so far is that it was built in '79 as one of five test cars for a new '80 model platform. they did tell me that this car was totalled in the test but past that they are still looking for the cars history. it is the only real '80 i have ever seen with matching numbers minus the vin with a pontiac 6.6L 400 and not the olds 6.6L 403 and the rtreason there is no vin is because GM said if it was a test car they never stamped the plate unless it passed testts and went into production. so how can i tell what it is and has anybody heard of testing during that period.

Here we go again. Hotrod Chevyz, there are no such animals as "oval" port Pontiacs. That's a Chevy deal for big blocks. Ram Air heads were "round port". That is, the exhaust port exit is nealy a perfect circle. That pattern was shared with '71 and '72 455 HO and '73 and '74 455 SD. The '68 "Ram Air II" was the ONLY other head casting with round ports.
The Ram Air V project was in '68 and '69, not '79. There were a limited number of GTOs built for testing. None were sold as street cars. Those heads were also used on the ill-fated 303 Trans Am engine for '69 and '70. Racers found them to have zero low-end response, and they were usually discarded in favor of the Ram Air IV heads. This information (on the TransAm project) comes from Herb Addams, himself. There were also a couple of experimental Ram Air VI engines (based on the 428, instead of 400).
The '72-'74 heads, you will get no arguement from me (except SD). They need too much work to make them happy. The '75-'79 heads are another matter. The 5C and 6X castings are VERY good. The only real drawback is the chamber volume. The intake ports flow the same or better than any of the other D-ports. The exhaust, with minor upgrades, is also on a par with the earlier heads.
The 670 head (unique to '67) was the first with the "big" valves (2.11/1.77). It had a "closed" combustion chamber, that impeded intake flow significantly, by "shrouding" the opening. This head was found on the vast majority of GTOs, and most of the Firebird 400s and Grand Prix with the HO option.
In '68, they introduced the "open" chamber. The purpose was to clean up the emissions (and it worked!), but a side benefit was the improved flow due to unshrouding of the intake valve. The open chamber improved flame propegation to the point where the AIR pump was no longer necessary to meet federal AND California standards for new cars.

While I believe you may have seen an '80 with a 400 in it, none were sold. Nor were 403s in '80. The Turbo and non-turbo 301 and 305 Chevy were the only options for '80.
For a turbo or blower engine, the large chamber heads are quite popular. Paul Spotts runs 6.80s (1/4 mile) with his alcohol front-engined dragster with a 400 and 8.0:1 compression, using 5C heads. There are several turbo cars going deep into the 7s using the 5C or 6X head (door slammers).

None of the information provided here is opinion. It is all well documented. Pontiac engines are NOT similar to Chevys, and comparisons or vernacular do not apply.

While I believe you may have seen an '80 with a 400 in it, none were sold.


in reply to this quote i own a confirmed (by GM) 1980 model test car with the pontiac 6.6L 400 numbers matching car. Except the vin plate was never stamped out and the car was totaled in testing (someone rebuilt it put a 68 vin plate on it and titled the car under the original vin from GM). Like i said GM has confirmed that it is rare but who rebuilt it they haven't found out. The vin on the title is the matching vin for the car but no vin plate. GM stated that it was probably the test car driver or another employee at the time. if any body knows anything about those test cars around that time any information would be helpful to finding out were my car came from. with no information there is no paper work and no paper work means boat anchor. this car has been neglected for more than 20 years and bringing it back is hard when i have to modify parts for the engine bay. this is why i need information about so i can find parts. parts such as the brake booster is not standard, it has a factory dual diaphram booster with mounts completly opposite those in '80 with 305 or turbo 301, i have used the one off my '86 and it mounts perfectly but i would like to know if there weree any other cars with that booster in '80. also i am running into problems with the heads with stuff working properly such as the rocker studs, it came with press in studs that i replaced with screw in but the valves are extremely touchy when adjusting and i am worried with clearance problems modifying them any more