1966 pontiac bonneville...400?
New to the site with stupid questions...I have a 1966 pontiac bonneville that I have owned now for 26 years. Can finally afford to do a few mods...the engine is bone stock 400...no idea on heads or year 72-76 from some donor pontiac in Alaska.
will be a daily driver and family car and very basic horsing around in...
I am wondering if this hair-brained scheme of mine is sound:
Looking to add kit from e-bay:
K KIT INCLUDES:
51-600-9 THUMPER CAMSHAFT
857-16 HYDRAULIC ROLLER LIFTERS
2112 TIMING CHAIN SET
995-16 Valve Springs
611-16 Valve Locks
503-16 Valve Seals
7775-16 Hi Tech Pushrods
the specs on the cam are:
Valve Setting in/ex hyd
adv: in 283
@.050": in 227
Valve Lift @ 1.5:1
Also looking to add:
Dual quad set up, idle to 5500rpms, dual 600cfm manual choke carbs with universal linkage.
Just wondering if this is reasonable to do...not looking to do any major machine work. This engine has 5000 miles on it and runs smooth on 89 octane...sluggish yes but smooth. Please advise. Thank you
How sound is the motor? Have you done a compression test or done a leak down test on it? How many miles on it now?
You need a good foundation to throw those parts on.
You're not going to like tuning that cam.......believe me. You'll need to change your converter, limit your mechanical advance in the dist to about 10 degrees, and play with your carb of choice just to give it some idle manners. Plus, without knowing your heads, you don't know your static compression ratio, flow characteristics or chamber design. You do NOT want to install that cam on an 8.0:1 motor.
If it's performance you're looking for you should start with checking the rear end gears and if they're not too bad (3.23, 3.55 etc) then move on to the heads. A good set of free flowing heads, set of headers with a good 2.5" or 3" exhaust system, 750 cfm carb, and a good curve kit in the dist will be a good starting point. A semi-mild cam in the 225* to 230* range will work nicely with this combo and will be easy to tune.
Slapping a grunty radical cam on an emissions slugged engine with crap heads will give you many more problems than you bargained for. Plus, you'll be hating all the money you've spent on something that will not run.
Thank you for your responses. This is a rebuilt 400 with about 5000 miles on it. What type of heads should I be looking for? Also didn't mention that I have a 455 that is in pieces with a set of 6x heads...just didn't want to get too messy with 5000 plus into an engine rebuild with a lot of machine work. Maybe I'm shooting too high but I just love that choppy nasty sounding cam and the look of dual quads..more show than go...I know that much.
I've heard that headers can be a bit of a problem with leaking...that's what my mechanic and muffler guy say and so just have the d port heads with 2 1/2 inch pipe with an H bar and flowmaster 44's...figure I'd try to keep this if I can. Just want a bit of umph. There will be no races, just quick starts at a few lights and daily driving.
what carb is on your car atm? no to dual 4s imo. what exhaust do you have now?
That cam will be a real dog off the line and wont idle correctly unless you put in a higher stall speed converter.It will run out of power quickly due to the short LSA.Plus the tall gears will limit how well it launches.
72-76 pontiac 400 s had large chambered heads (due to manufacturers attemps to meet EPA specs) so your build strategy may change /evolve somewhat here.Its a good thing.
What heads are on the motor as of now? are you going to run those heads?
If you want to get the most bang for your buck, have a fun car with good power, stroke it to 462 with a kit from butler.Use KRE D prt heads with the 85 CC chambers.The dual quad setup will run well with them, also with the block zero decked and the KRE heads, you will have a good quench, so pump gas is feasible.
You will need a 2000 rpm stall converter and a gear change from the 2.56 you prolly have, to a 3.08-3.23 would be better.3.55 would be Ideal.
Naturally the butler kit has forged rods and ross forged pistons.Very much needed where you are going with this build.
NOW.... the problem is , building that sort of power takes time and money to do right. You wont be driving it in a few weeks. If your serious about the build, I would recommend finding another bare block and start from there , leaving the engine in the car intact and runable for the time being, so you can still drive it. Then when you elephant engine is done, just swap it out over the weekend.
Having a car torn apart for a long period of time tends to be an oppresive matter....parts getting lost, no driving it...bummer....loss of interest. Dont go there. Build a motor to swap.If the new engine ever goes bad (hope not) you can put the other one back in and still drive.
There are stiull plenty of 400 blocks around to be had.If your building a stroker , like the 462 CI stay away from the 557 casting as they are weaker in the main bearing web area. That is an important area for strength as you are increasing the forces that act on it by increasing the stroke and the energy produced.
Give it some thought, and post back. There are some WAY cheaper alternatives to getting more HP and torque without a ton of cash and parts involved.
Oh and buy the way, the cam you posted wont make enough vacuum to run the power brakes, so a hydra boost may be in your future as well.
Wow! Thanks to all of you for your input! Maybe the way to go is to build the 455 block that I have with 6x heads. On rethingking this thing and being honest with myself, I just want dual quads and a lopey idle. If the above will accomplish this then there is a good starting point. If other options are available then please let me know. I am open to all suggestions and trying to keep costs down...who isn't?
Can finally afford to do a few mods...the engine is bone stock 400...no idea on heads or year 72-76 from some donor pontiac in Alaska.
will be a daily driver and family car and very basic horsing around in... [Quote]
The least exspensive route would be a Comp Cams XE series cam. There has been a little contraversy about them in the past concerning wear and failure, but if you follow the break in procedure you shouldnt have any problems.
If it were me , I would run a Comp cams XE 262 in your 5000 LB tuna boat.
Stock compression ratio is 8.0 to 1 if you have the # 7J2,7K3, or 4X heads. If you have a 1973 or later engine it will have lower compression heads and some power making capability will be lost.
First thing to do is to ID the motor you want to run. Get year date code from back by the distributor.Also engine casting number. Then get the numbers from the heads.the number will be on the top of the center 2 exhaust ports.
Seeing that you have a 455 in bare form, that would be your best bet to build.
First, you would be able to keep the 400 you have as a runnig spare, and if you are going to spend money to build an engine, dont take apart a perfectly good running engine, build a non runner, end up with 2 engines.
Also the 455 will make better power for the street with your heavy sled. There is no replacement for displacement.
Quadrajet carbs and stock pontiac intakes work real good for a street build, and would be an attribute to your 455 build.
If it were me, I would build the 455.
dual quads and lopey idle does not make the car fast or fun to drive.I mean no insults but,if you are not a gear head dont use 2 carbs. If you want the look and the fun first,consider hiring someone to do the work.
I have an idea that might give you the cool factor you want. You will have to do the research yourself,,,,
1984 corvette had what looked like dual 4s but was actually dual fuel injection(2 throttle bodies) edelbrock makes a conversion where fuel injectors are drilled and tapped in the individual runners and the throttle bodies are converted to dry,,,air control only.
you could do this same thing except convert the low rise dual 4 intake for a pontiac and use the corvette style bodies ( look like carbs under an air cleaner).Talk to latech about a "small" camshaft for sound,use full 3 inch exhaust and enjoy driving a modern ish fuel injected cool sounding car that performs well.
If you want serious power,then you will need more items.imo,I think thats enough for a daily driver and the fi will perk up the low end
A good sounding car can be easy. Decent headers and a dual exhaust with a crossover pipe. Heat crossovers in the heads should be blocked(recommended)
Agreed with LATECH. You would HATE that cam. As an engine builder and been onvolved in thousands of "projects" over the years, many times, one's "eyes" are "bigger" than their stomach. Rumpy-rump engines SOUND cool, but are a pain to operate.
A Bonneville is a classy "dark sider". That's what Pontiac people use to refer to the "big" cars. it is a TANK compared to the Pontiac "performance" cars of the era (GTO, Catalina, "2+2", Ventura). The Bonny has a longer wheelbase than Catalina. A nice "cruiser" is the best thing to do with the Bonny, IMO.
If you're REALLY interested in pumping up the Poncho, get Jim Hand's "How to Build Max-performance Pontiac V8s" published by SA Designs. Get educated on the strengths and weaknesses of the Pontiac.
The 400 block is physically stronger than the 455 block. The "stroker" kits make a much ore effective engine than a "built" 455. Cylinder head casting numbers are among the most imnportant pieces of information you can provide. Compression is controlled by the chamber volume in a Pontiac, not the piston configuration.
That car would do great with the 455 in it and along w/the 6X heads- especially if they're the 6X-4 heads (the "dash-4" is a "secondary" identifier, explained here). The 6X-4 heads have a smaller combustion chamber so the compression w/a 455 will be better than if you were to use a 455 head w/their larger chambers.
I agree a single 4 bbl like the Q-jet will work great- but if you're bound to put dual fours on it, go for it- just be prepared for the tuning and possible loss of performance. Get rid of the points distributor. I like and use the GM HEI but the HEI won't fit using some dual four intakes. You can use a points eliminator kit in the stock points-type distributor if it's in good shape.
If it was me, I'd drive it w/the 400 until the 455 was built. And while accumulating the parts to do the 455, I would be doing some heavy researching of the Pontiac engine in general. It's not a Chebby, so much of what you read won't apply to the Pontiac.
Some info to get you started:
• Pontiac info and sites
• Pontiac V8 engine
Here is a cam for your consideration; Summit Racing SUM-2801 - Summit Racing® Camshafts - Overview - SummitRacing.com
If you want more duration you can get a 2802 cam. Summit offerers these in kits with lifters also.
A Pontiac 068 cam would also work.
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