Camshaft, head, tri power question
 

Hello, I am looking at taking my 67 catalina up a notch and have some fun with it. It's a stock 400 2bbl w/ 142 heads. I am looking at grabbing a pair of #62 heads to bump compression and have the bigger valves, I also have a 65 tri power set up and I will be converting to a 4 speed stick.

My question is what is the best hydraulic roller cam choice I could pick? I am pretty new to pontiac engines and what they like and don't like. I'm not looking for a race car. I'm looking to build something fun that I can jump in and drive cross country if I wanted to. A factory spec'd cam would be fine with me as long as it will all work together.

With the 62 heads you will also need a full set of 9.145” long push rods because the ones you have are too short.

You will also need a upper rad hose for a Tripower.

I would take a close look at the pistons when you have the heads off. If they are original to the short block, I'm not sure if they will have the right valve reliefs since those heads have the 389 style valve angle. If they are the old style valve reliefs, you will be limited to around .450 lift or less if you run the 62 heads.

I used to run a '67 400 block out of a Catalina. The thing to watch is the valve chamfers on the block. The '67 400 blocks have the valve chamfers at the top of the cylinders machined for the old 389 valve angle. At least on my block, that limited me to just over 550 lift with 670 heads. You should check how much valve travel it takes to hit the block before you select a camshaft.

For managing pump gas, select a cam with about a 225-228* intake lobe and 112-115* LSA. All the stock pontiac cams were on a wide LSA for a wide powerband and mild idle. Avoid fast ramp XE-type grinds with tight LSAs, they tend to want to detonate around 10:1 compression when combined with highway gears and tight converters or manual tranny.

Also consider the cost of converting the 62 heads to a roller cam. Sometimes longer valves and springs that set up at 1.7-1.8" IH are required for rollers. That can really add to the head cost vs a set of aftermarket heads ready to go.

I should have rephrased, I'm wanting to run a stock ram air 3 or 4, or other but as a roller. Not looking for big lift stuff. Just something to match the rest of combo. With everything going on with flat tappet stuff I don't want to chance it.

Just put a cheap summit 2802 in it and let it eat. I run one with 62 heads on a 400 in a '67 GTO clone and it's a blast.

Rollers are expensive and their typical lifts are .485 to .500 even on baby rollers. And most of Butler's stuff is comp-based. Lately the tie bars or the needles on the hyd rollers have been breaking and taking out builds. I don't consider a roller much safer than a HFT. With a HFT, its all about the crown on the lifter and the lobe taper, which you can inspect for. If it goes flat, throw it on the pile and throw in another one for $200 cam and lifters combined. I've taken apart an engine that wiped several HFT lobes, and it didn't even show up in the bearings. On the current engine, it ate a 30 year old Crane HFT grind. I changed the oil, threw in the Summit 2802 and kept going. It seems the less you care about it, the better it runs.

I would stick the factory 068 flat tappet hydraulic in it. Personally I wouldn’t want anything more than that in a heavy big Pontiac cruiser with a stick shift.

That’s the RAIII cam used from mid-1969 and on, it’s also the Tri-Power GTO cam used in 1965-1966 as well as tons of other 350, 389, 400, 428 and 455 performance engines.

You want low lift with the likely piston to valve clearance issues (early piston valve reliefs and late heads not matching) that are going to limit your hydraulic roller cam choices to pretty much nothing.

If you’re worried about flat tappet cam and lifter failure I’d say the factory slow-ramp low-lift cams are a pretty safe bet when combined with a top quality lifter.

A set of cleaned up 62 heads are going to be 72cc's or a little smaller which computes to about 10.2:1 compression with flat tops .008" in the hole.

With those stock B body pistons you can’t run a RA4 cam even with 1.5 rockers, so get that off your list of possibilities.

This cam from Bulter’s HR cam should work with .450” lift. The 115 LSA spreads the events out and provides more piston to valve clearance. You can have a HR cam ground with about any lift you want.

https://butlerperformance.com/i-3164...tegory:1234841

That roller looks like a real possibility for this application. What comp lobes does it use? Looks like a decent amount of seat timing, slower than a XE lobe?

What springs and retainers would be needed? Would this set up at 1.6" or would you need longer valves? When I set up the Voodoo HR on my 670s, I had to go to 1.8" to find a spring that would set up at the correct pressures with enough lift.

I thought the 62s were in the 74-76 range stock? My 62s and 2802 pump 170 PSI on a 400 near sea level. That should be about 9.8 compression or so?

That cam does not have profiles list anywhere that I know of. It definetly has less acceleration than a XR Comp hydrualic roller profile. It would be difficult to compare it to a XE flat tappet. But if the install height was set in a stockish range of 1.6 to 1.63 the Bulter cam would work with the same 995 spring and 940 retainer combination comp uses on most of the XE flat tappets cams. It is a very easy spring package to put together.

For what was described I would prefer to use a Bullet or Howard’s HR cam that allows for the use of a stock distributer gear. They are all 4/7 swaps. Those lower lifts work well for the 2148 LS/LT drop in style dog bone lifters too.


I am not sure where the compression would end up on a 67 engine with heads mentioned. Seems like those had an odd piston with smaller valve reliefs like an 389 and have different cylinder scallops. But I would assume a 62 head with a valve job and surfaced would be at least 75 cc to 77cc.

I would be open to a flat tappet knowing a good lifter to use. I have been out of the engine world for about 12 years lots of things have changed. This is my first pontiac project.

I figured I would be about 10.1 with those heads. I'm just looking bump this 265hp 2bbl engine up a little and have a fun car, tri power, 4 speed. I don't really car or expect it to be a track monster, that's not my goal. I will check out the pistons when I get the heads off. That will be awhile from now, I'm researching my options and wanting to have a good smaller cam, lifter, spring combination picked out for when it's time. It sounds like the 068 cam is a good option.

Note taken on the ram air 4 being to big. Tha k you for that information.

I've always had stock-ish type Pontiac builds over the decades and never liked the Ram Air cams for my purposes, which was daily driver and road trips. I like a cam like the 068 because it gives usable power in the rpm range the engine is in most of the time and is good on gas as well. With an 068, I can run a lazier rear gear for less road rpm and less wear and tear, which gives me guiet cruising and high MPG's. Ram air cams want a stiff rear and gear and make power at high rpms. Great on the track, but for me on the street, not my bag. This '67 with an o68 cam, TH400, original 400 engine, Q-jet, points distributor and swapped in 2.56 rear end averaged 20.6 MPG on a 2700 mile cross country trip in 2023. Car has 260,000 miles on it, engine was rebuilt 90,000 miles ago. Attachment 660262

Thank you for the info, and that is awesome!