I have a '65 425 10.25CR motor with A heads, I am going to be in the motor adding roller rockers and valve springs. When I rebuilt my motor (new rings and bearings) I just freshened up the heads (new valve stem seals), but I never rebuilt them they work fine and I don't have any problems with them. I am thinking abut putting in a new cam while I am in there, but my questions is what would be more beneficial for me performance wise new cam or port and polish my heads? This is just a street motor, but I figured since I am going to be working on it, might as well spend some money on it.

 

That's a double edged sword, both would be beneficial but then again why port them with a stock cam? And conversly your cam choice will need to coincide with the heads etc.

Depending on how much more hp/tq you're looking for I'd probably do the cam, it'll be cheaper first of all and give you noticeably more power. Do you have a stock intake? carb? Exhaust? Valvetrain? How much lift will your springs handle, gotta weigh out all the variables.

 

Performer intake, holley carb, dual exhaust manifolds, stock heads, upgrading valve train currently...........

 

I'd get a decent cam first, valve job if needed. Forget the rockers for now.

 

X2 but don't do the Xtreme or VooDoo stuff, not enough off the seat time for stock heads with exhaust manifolds. Jmo.

 

x3

 

Valve job 1st, if needed, guides??? Were they done?
then the cam.
Why the roller rockers?
My opinion.

Jim

 

Can anybody make a suggestion as to what type of cam to get? and where? I have been looking on summitracing and the only cams that seem to be reasonable for street use in a 4000lb car and available for a '65 425 are these:

http://www.summitracing.com/parts/HRS-510021-12/

http://www.summitracing.com/parts/CRO-56260/


Any suggestions?

 

I would get something in the size range of Comp High Energy 260 for low end, 268 for more upper mid range, still staying under 5000 rpm. However, you can't get a regular Olds cam from someone like Summit because you have 45 degree lifter angle, although you have the standard .842" diameter lifters. Most cam companies will make you a cam for the 45 deg. Most late Olds, and all from 68-up are 39 degree.

 

I can grind you a 45 degree cam, $235.00 plus shipping with .842 lifters. Takes about 10 days total.

For your combo I'd do about a 220/228 on a 110 or even a 108, depending on what gear is in you car? You would hear it a little ( do you want that?) and it would be compatible with your stock valvetrain if you want.

 

The car has a turbo 400 with a switch pitch trans and a 3.08 gear. I want to be able to hear the cam, but not ruin drive ability of the car. Being compatible with stock valvetrain meaning what? Stock springs?

 

Yes stock springs provided they have enough pressure, but moreso stock pushrods and rockers.

To hear a cam with manifolds is tough but it can be done, smaller duration on a tighter lobe sep will help and give you good throttle response.

Going thru the Erson library I'd probably do something like this;

Adv. 279/295, 223/235 @ .050 on a 108+4 (advanced 4 degrees) with .483/.523 lift. It'll have a bigger exhaust lobe than intake, you need it using the manifolds. You'll only need about 110# on the seat and 275 or so open, less if you're not going to run it hard. I sell springs too.

 

Hmm........ well how about going for best performance and not necessarily best sounding cam, how would the specs differ and would I be able to use stock parts as well?

 

with the carb and intake you have already , I would up grade the cam, and lifters.
do a home mild port job. You dont want the combustion chamber shinny and smooth.
just do a mild bowl blend and clean up any casting flash in the ports.
Any chance of putting headers on it? that would be BIG improvement with the
mods mentioned above. Maybe change the rear gear to about 3.55

 

This one should give you good performance. The tight lobe sep will give you the tone you want and build more torque sooner, just what you need to push that land yacht along with the 3.08 gear. We could do it on a 110, that would take a bit of tone away and a bit of low end but give you more midrange, your call.

But given you have stock untouched heads, yes I would normally do something with a bit more off the seat time overall. However you have that tall gear and a TH400 that takes another 30hp or so to run over a TH350. Plus with manifolds that kinda straps us even more and we'll need the vacuum a smaller intake lobe gives us for the above reasons.

 

Headers for a '65 Delta 88 a virtually non existent unless they are custom made, which I would like to do in the future just not any time soon......

 

Does cam come with any type of warranty? Also what lifters do you use? and can I buy the cam with out the lifters and if so how much?

 

Warranty is technically non-existant cuz it's regarded as a race part. However if it goes flat or whatever from core failure etc. it will be replaced free of charge, pretty much the industry standard.

Lifters are Erson/Morel, made in U.S.A. Cam alone is $180.00 plus shipping.

 

How many miles are on this engine?
Seals are not a rebuild.
.004" stem clearance on a 4 cyl Pinto engine lost 10 hp as tested by David Vizzard. You have 2X the valves of that test.
Engine lost 20 hp with .006" clearance.
If your engine is over 100K miles, I'll buy you lunch if 1/2 your guides are good.
All this cam talk is putting the cart waaaaaay before the horse.
Jim

 

Agreed, first things first.

 

I corrected the numbers, Mark. There were several tests done, all lost good amounts of power.
Did not mean to come across as angry, just wanted to get the point across that it is best to freshen heads before the cam goes in.
The valve job alone (no port work) will bring more power.
Jim

 

I never said that the heads were rebuilt, I am also looking at rebuilding my heads or buying some rebuilt ones already.............

 

Fair enough.
Good to hear it.
Jim

 

If you can find a set to have done and swap out it makes sense, sure is nice to know what you're in for right away, plus it may save you some time.
Most sets go for about $100.00 or so, you could probably sell yours to someone else in the same situation.

Whatever you do do it right and put springs in it that give you the option to do something else with a cam if you want. It can certainly pay off to look ahead.

 

This whole thread hits pretty close to home, as it's something I've been contemplating for a while with my 425. It, too, is a 1965 A head engine, two barrel, set up with a B body frame/steering combination. (The front end of a 1964 Delta 88 was transplanted into a 1953 88.)

At any rate, I'd be looking at almost the same circumstances; no headers, although I'd get the stock (repro) dual exhaust manifolds, switchpitch TH400, 3.08 gears, 15" wheels, 235/60 tires. I'll be using a Q-Jet and an old Offenhauser 360 manifold (the manifold is not as good as an Edelbrock for bottom end, but it's more unusual :-) )

I'm not looking for a race motor; just a strong, reliable, affordable, pretty engine that will occasionally make the aged tank it's in move faster than it looks like it should.

I have no history of any kind on the engine, but it runs nicely as is; a small amount of smoke in the crankcase breather, nothing visible in the exhaust. Some minor "loose change" ticking from the engine, nothing major.

My plan was to pull the engine, disassemble, check specs to see what machine work needs to be done. I would automatically assume bore, align hone, balance, deck, heads, basic port cleanup. Nothing fancy, just looking for very clean tolerances. Ability to reuse stock components (rods, crank, pushrods, etc.) a plus, but would replace with better than stock if replacement necessary.

Given all that, I would prefer a custom ground cam, replacing the stock cam even if it were still in good shape, along with a stronger timing chain. I've been considering running the car down to the dump to get it weighed; it's basically complete, further work won't appreciably change the total weight of the car.

Anyway, I was looking through the catalogs, not really looking forward to trying to call them up and work out a 45 degree grind for this kind of a build. Finding out cutlassefi does this takes a big load off my mind. Another reason to be happy to browse this site regularly!

 

I have to go along with Jim here. IMHO you should take a serious look at your end goals and try to put together a budget for that complete package. CutlassEFI has a good reputation here for helping people choose the proper modern grind cam for their application. Don't try to find the cheapest horspower bolt on or best bang for the buck parts. Look at the big picture and do it right the first time. The 425 is a great engine. You should keep the A heads and don't let anyone port them that isn't well versed with Oldsmobile head designs. You might end up with less power. Change out that rear gear and step up to some of Smitty's headers-
http://www.mjproformance.com/
You'll be really glad you did. Than choose the right cam for that application. All the 425 CI engines came with steel cranks, but in higher output Olds engines the block is still the weak link. You might want to look into a halo from-
http://www.jsmachineoldsmobile.com/home.html
I think it's money well spent for bottom end piece of mind. You should also pick up Bill Travatos book. The thirty dollars you spend on it can save you thousands down the road.
http://highperformanceolds.com/phpbb...hp?f=28&t=2712