Jump to content
Forums Gone... but not forgotten!
Pontiac of the Month

dues70's 1970 Pontiac Bonneville

2020 July
of the Month


  • Content Count

  • Avg. Content Per Day

  • Joined

  • Last visited

  • Days Won


TWO LANE BLACK TOP last won the day on April 12

TWO LANE BLACK TOP had the most liked content!

Community Reputation

165 Excellent



  • Rank
    Century Club
  • Birthday 09/07/1961

Contact Methods

  • Website URL

Profile Information

  • Location
    North Carolina
  • Interests
    Hot Rod cars motorcycles engine building Anything mechanical . Jack of all trades .Custom Fabrication ,welding ,Machine work . Firm believer anything can be fixed . Navy veteran. Do everything from fixing carburetors to AM FM broadcast and cellular phone towers . Have owned several Pontiacs thru the years.Currently own 1996 Firebird and 1997 firebird Formula that I bought new.

Forever Pontiac

  • Name
    Kenith McIntosh
  • Gender
  • Year
  • Car
    firebird formula WS6
  • Trim
  • Engine
  • Style
  • Color
    bright red

Recent Profile Visitors

4,817 profile views
  1. There no harm in opening the oil pump to look inside for any contaminants...When you pull the cover just make sure that you don't damage the paper gasket...The gasket thickness is instrumental in determining the clearance of the gears inside the pump..Also mark the gears with a sharpie so you can be sure that they are oriented in the same position with each other as they were to begin with..Upon reassembly...A very slight amount of wear is normal on the cover...Something else that is often overlooked that is definitely worth checking...When you reinstall the oil pump..Drop the distributor in without the hold down bracket or the gasket and let the distributor and the oil pump drive just rest in position naturally....Then measure with a feeler guage the distance between the bottom of the distributor and the engine block...Then measure the thickness of the gasket...Most gaskets are around .020 thick..but thicker ones are available... So if the measurement between the two is excessive... more than .005 - .010 when you lock the distributor down it pushes the oil pump drive rod down on the pump gears too tightly against the cover of the oil pump and will cause premature wear...Send metal shavings through the entire engine and eventual failure of the pump...In order to prevent that from happening you would have to grind down one end of the oil pump drive rod in order to attain the proper clearance...Ideally when the distributor with the gasket..locked in place the pump drive rod should have right around .050 to .060 of up and down play between the pump and the distributor....(measured with a feeler guage at the oil pump) Looks like a piece of an exhaust valve seal that was in the oil pan.....
  2. As Bear mentioned you might have gotten lucky and only have the exhaust valve sealing issues...Since you're going to have to pull the heads anyway..It would be a good idea after the heads are off...To roll the engine over by hand to make sure that all the pistons are coming up to the same height in the bores... If they all don't have the same distance from the deck to the top of the pistons that would be a sure sign that you have a bent or kinked rod...Pay special attention to #s 5 and 6....if they are all the same height (none of them lower in the bore than the rest of them)...You're more than likely good to go as far as the bottom end goes....
  3. Wrongway.. You can use an old spark plug and knock the ceramic center out of it with a hammer and a punch and grind or cut the electrode off and weld a Male fitting to the remaining outer part of the plug...That fits your chuck on the air hose and use it for pressurizing the cylinder.. Did the original valves have a three or four degree angle valve grind on them..?? What about the valve seats..?? It's not too late
  4. Wrongway.. You can use an old spark plug and knock the ceramic center and the metal electrode out of it with a hammer and a punch and grind or cut the electrode off the bottom and weld a Male fitting to the remaining outer part of the plug...That fits your chuck on the air hose and use it for pressurizing the cylinder.. Did the original valves have a three or four degree angle valve grind on them..?? What about the valve seats..?? It's not too late to disassemble the heads and grind And/or lap the valves in as there is only a very narrow area (only a few thousanths wide) that actually contacts the seat the other two or three angles are ground to facilitate efficient velocity and airflow..The thing is the expense of New Head and related gaskets...I would not reuse head gaskets once they have been torqued whether they have been run or not.. You should be able to determine the original valve angles by using the broken valve faces (hopefully you still have the broken parts) as a guide using a protractor to find the angles... If you duplicate the original angles they should match up with the valve seats... You can have a machine shop grind the valves only (cheaply)...To your specs..Then lap them in and reassemble the heads Yourself...You can also closely inspect the guides and the springs/locks/retainers while everything is apart... But before you do all that do your air test first and then decide where to go from there...
  5. Wrongway... If you suspect a valve sealing issue...A good accurate way to check if your having valve sealing/bent valve/weak springs issues without tearing the engine down...Remove all the rockers...Then take a long straight edge and lay it across the tops all the valve stems....They should all be the same height..If there is some of the valves that are lower than the others by .002 to .003 or more...(Use a feeler gauge between the tops of the valve stems and the straight edge)..That is a real good indicator of a weak valve spring/slightly bent valve stem..ETC..which will cause the valves not to seal correctly and not hold compression...If you have a couple of the valve stems that are higher than the rest of them...That is a really good indicator that whoever did the heads cut the valve seats too deep..If that is the case and when you set the valve lash the same on all the valves the taller ones will not close completely or tightly enough because they are actually set too tight..If that is the case You can grind the tops of the stems to the same height as the rest of the valves...Provided that they aren't anymore than 4 or 5 thousandths higher than the rest of the valves...Anymore than that and you would have to use an adjustable length pushrod on those particular valves in order to keep the geometry the same on the whole valve trane...Also this may sound crazy but it might not be a bad idea to make sure that all the push rods are all the exact same length...While I'm thinking about it upgrading from 5/16s pushrods to 3/8s is a very cost effective worthwhile improvement.... Edit...Also if all the valve stems vary slightly in height from each other...and they are all not all the same...It can also cause erratic vacuum readings and crappy idling issues....Due to all the valves not traveling/opening/closing the same distances....Hope maybe all this helps you too figure out what the problem may be.....Without having to take everything apart.... TLBT..
  6. I wasn't 100% sure....Thanks for clarifying.. I learned something.... I don't want to post inaccurate info if at all possible...
  7. You're Welcome happy to help.... If your having an issue with the gas not getting from the tank to the fuel pump and you want to run (not drive) the car...You can disconnect the line running from the tank to the pump and run a temporary line out of a gas can right to the input side of the fuel pump and it will pick up the fuel just like it would if it was coming from the tank....
  8. The shift pattern changed to PRNDSL in 1965 (Hydramatic)...Cars equipped with the 2 speed Powerflow..(Pontiac nomenclature for the Powerglide)..PRNDL.. I don't know if changing to a later model neutral safety switch...Would be beneficial for you or not....
  9. The earlier Pontiac engines are reverse flow cooling...I'm pretty sure (not 100%) the changeover to the conventional water flow was some time in real late 1964 or The beginning of the 1965 model year...Because of that the earlier cylinder heads won't interchange or Visa versa with the later model engines...
  10. Yes it would work....If the floats are good in the carburetor (not heavy) so it will maintain the correct fuel level in the bowl and operate the needle and seat correctly to meter the proper amount of gas and not constantly flood or not run at all.... Why not just run a temporary soft fuel line from the fuel pump to the carburetor...?? You should be able to get a couple of male fittings with the the correct threads to screw into the pump and the carb at any auto parts store then clamp the rubber gas hose on to the fittings....Just make sure that it isn't on the exhaust manifold or rubbing against anything that could potentially wear a hole in it.... Rochester two jets are excellent carbs...
  11. Now that things have calmed down some...I Have been given the green light to proceed with the build.. Upon further inspection the cylinder heads that the owner wanted to use are pretty much garbage...The combustion chambers are horribly pitted and can not be cleaned up enough to use in a blower motor without fear of detonation....As you can see the area between the valves (1st pic )...So I came up with another engine (454)..that is donating the heads and maybe the bottom end too...Over the next week or so..I will install hardened valve seats (the heads are 1971 LS-5 non EGR casting # 672292.... 113 cc combustion chambers)..New valve guides and a 3 angle valve job and stainless steel valves..Will provide more details and photos detailing the process as I move along.... The owner has also come up the vehicle the engine will be installed in.....The plan is to leave the truck cosmetically the same on the outside and camouflage it as much as possible on the inside...Although a supercharger might be kind of hard to hide..LOL.. Stay tuned..
  12. Didn't get the Blue Angles or the Thunderbirds...Got Airforce one flyover instead...
  13. Cool car...Hate to see that you're having transmission issues...I have a couple of questions....First off I'm not trying nor do I want to come across as being a smart ass..or condescending in anyway shape or form... So please don't take it that way...I also don't want to put up inaccurate Info if at all possible.... Are you 100% sure that the trans is a Dynaflow and not a Hydramatic..Or a Powerglide...?? I ask this because Dynaflows were exclusive to the Buick brand and were only used in Buicks...The exception to this is when there was a catastrophic Fire (Burned to the ground) at the Hydramatic plant in Livonia Michigan that shut down production for an extended period of time in the fall of 1953..As a result of that...GM had to scramble to come up with an automatic transmissions for use in cars that were supposed to be equipped with the Hydramatics...So they hastily reengineered the mounting points of the dynaflow trans case for use in other GM cars...They were for sure used in thousands of Cadillacs and Oldsmobiles in 1954 and possibly into early 1955..If you bought one of those cars they came with a certificate that would allow you to take the car back to the dealership and have the Dynaflow swapped out for a Hydramatic free of charge...Once production restarted and the supply chain was up and going again...Automatic trans (hydramatic) equipped Pontiacs of that same time period used the cast iron cased Chevrolet sourced Powerglide...Instead of the Dynaflow...The Powerglide was adapted to the Pontiac engine via a steel band adapter plate about an inch or so thick so it would bolt up to the Pontiac engine block...As with the Oldsmobiles and Cadillacs the Pontiacs also came with the Certificate to swap out the Powerglide for the Hydramatic free of charge..The seperate steel adapter band between the engine block and the bellhousing remained afterwards and continued to be used on the Chevrolets equipped with the cast iron case Powerglide transmission until it was updated to an aluminium case in the early 1960s... If your Pontiac 100% for sure does have a Dynaflow...Instead of a Hydramatic which may or may not Be possible..?? Since it is on a commercial type chassis and could be or not..??? More closely related to the very early 1955 producton Cadillac ambulances and hearses..?? Than a standard Pontiac station wagon... If you could be more specific as to exactly what the symptoms of your transmission problems are...It could very well be just a simple adjustment to cure the problem...That could be easily done yourself...There are lots of pages of adjustments in this manual... For different symptoms....Too many to try to post them all....Without norrowing the issue down some... TLBT..
  14. No haters here...Welcome to the site......
  15. Just in case anyone is interested.....Here a little background info on the Pontiac 370 CID engine ( 4.062 bore × 3.562 stroke )... Was introduced as an improved version of the 1957...347 CID engine (4.00 bore × 3.562 stroke) with different cylinder heads with larger exhaust ports and different better breathing exhaust manifolds...The 370 Was only available in 1958 and was used as the optional engine for the 1958 Bonneville with the Rochester mechanical fuel injection set up...Rated at 310 horsepower and 400 ft-lbs of torque....But could be had with tri-power or single 4 barrel carb...They were also used for one year only (1958) in the factory backed Pontiacs for NASCAR racing although without The Rochester fuel injection set up..The 370 was replaced with the 389 starting in 1959...There were only about 500 or less total 370 engines produced and only in 1958....
Tired of these Ads? Purchase Enhanced Membership today to remove them!
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.