defiant1

Picked up a '65 425 (Casting Number 386525A) with A heads. Trying to get an idea if the stock configuration is good setup performance wise.

Not trying spend a lot of money on this motor (I know, I know, nobody tries to spend a lot, it just happens) but want to upgrade parts that make sense. I am not trying to make this a "The best way to rebuild a 425" thread. This is more of a way to garner feedback from those who have had experience with 425 motors (good, bad, or ugly).

For example, is the factory intake manifold acceptable, which exhaust manifolds work the best for dual exhaust, is the factory camshaft specs the best or will an aftermarket grind be ideal. What is the ideal CR? Oil Pressure Problems? Cylinder heads flow characteristics, etc.?

Just looking for constructive feedback and practical experience for those you have built up a 425. Either to factory specs for a daily driver or those who built it for performance.

I will be taking the motor apart over the next few months and clean and inspect everything. This winter I will assemble it. Over the next 6 months I will be looking to get parts as needed (either on this forum or wherever) based on your feedback.

Thanks
d1

Oldsmaniac

I would say this BB is no different than a 455 or 400 or even the smallblock as far as what will make it run/perform better. Better breathing/flow equals better performance. The cast iron dual plane manifold if fine but heavy. The A heads are good and they dont have the AIR bumps in the exhaust ports but if they have the early rockers you may have difficulty finding new ones so an upgrade to later heads may be in order. You prob have the uncommon 45 deg cam angle so be aware of that when picking a cam. Stock 442 BB exhaust manifolds are fine if you are not choosing headers. I built a 425 for my street strip 67 442 many years ago. At the time Mondello was pretty much the only game in town for getting an Olds to put out HP and live. I built the engine to his specs with oil restrictors, higher pressure oil pump, increased oil pan capacity. I had the rods side ground with oil reliefs and had them shot peened. Had TRW 10.25 to 1 flat top forged pistons. Had some porting done on a set of G heads with exhaust crossovers blocked. Had a stout 590 lift cam and kit from Engle with adjustable pushrods and stock rockers. I used an Offy 2 4bbl intake with dual 500cfm Carters. With a Muncie and 466 gear I ran 12:10's in the quarter and shifted at 6000 Rpm. The engine would rev to 7000 with no problem but preferred not to take it there often. It lived very well and is still intact.

Erinyes

Heh. In my 53, the PO had swapped in what looks to be a completely stock 1965 425/TH400 switchpitch. A heads, two barrel, single exhaust, looks like the original 1953 rear end (I checked the stamp on it once, if I remember right the gears are about 3.4 or so - open spool, of course, it's just an Eighty-Eight).

My BIL's brother was in town pouring concrete, and he went nuts when he saw the old beast. He'd leave it exactly as it is, smashed fender, rotted interior and all, and go humiliate the lowrider set. He was so carried away, when I left I jumped on it a little. Not much, because I live in a Very Small Town, but to my surprise it actually broke a tire free. After a few seconds, I decided enough was enough, even though I wasn't at full throttle by any stretch, and let off the gas. Turned out I left a 60 foot patch on the road.

Yes, the 425 seems like it will run pretty well bone stock.

Can't wait to add the dual exhaust, Offenhauser 360 and Q-jet, and beef up the ignition system just a trifle. That's as far as I'll go, though, unless I ever have to tear it down.

defiant1

Thanks guys. This is the kind of feedback I am looking for.

d1

64Rocket

The "A" heads are very good heads. Do valve pocket work and smooth out the roof and should be good. The heads have rocker studs already, I would get after market 3/8 x 3/8 rocker studs and Comp Cam guide plates. Use small block Ford roller rockers, should be a nice improvement .
It is a 45* cam bank. Depends on what you are going to use it for, maybe a 230/236 @ .050, 5 something lift and a good dizzy, will be nice. For the street I like the edel. o4b intake, looks stock and works well.
The "W/Z" manifolds will be very good, unless you go headers.

What are you planing and what are you putting it in??

Gene

defiant1

I don't have a vehicle in mind yet to put the motor into. I have been looking locally for a project car. I envision something in flat black primer, with no A/C and bare bones interior. I have seen some '51, '52 Chebby 210s locally that would accommodate the motor. I am leaning toward the "Rat Rod" look with an Olds power plant and drive train.

Not a whole lot of Olds 88, Delmonts, Deltas, Dynamics, Jetstars or Starfires in my neck of the woods to choose from. Basically, my options are open at this point.

Thanks for the motor specs, Gene.

Shaun

defiant1

Looks like I will be upgrading the '65 425 "A" heads with bigger intake and exhaust valves.

Going from: 2.00" Intake & 1.625" Exhaust to: 2.072" Intake and 1.685 Exhaust.

Any issues (performance or otherwise) I will need to be aware of?

d1

Fastbrianman

Valve springs from the factory are on the weak side, Take advantage of modern valvetrain and you will be surprised at how well she will run.

Steve O

Timely thread

I have a cobbled together bomb Im almost done putting in my 84 Ninety Eight 4 door

It's got a little of everything...

It has a 73 F 455 standard bore block with a backyard hone and pressure wash/Brake clean bath...

The crank, rods, and pistons and main and rod bearings came out of a 66 Toro 425, the crank and bearings were original and perfect so they just stayed with their journals into the new block

The Toro flexplate and damper were still good old junk so they got used too...

The 425 block was the 39 degree with the .921 lifters, I sold that because I allready had my trusty, and slightly rusty 214/224 .472..496 cam and lifters that had ran in 3 other engines already that I wanted to use with the 455 block...

The rust was very light and cleaned right off with some Scotchbright, the lifters have always been kept in order with their lobes...

I used Hastings Iron rings and added a NEW HV oil pump and used the Toro pan and rear windage tray, the hump was beat flat with a sledge on the leg of my wasp infested engine hoist....

It got a NEW Edelbrock double roller timing chain...

The heads are fully ported Ka's with new valves, guides, springs and a fresh valve job...

Push rods are some old thick wall Smith Brothers from my Race motor, and stock rockers shimmed with cheap lock washers for the right lifter preload...

72 Toro valve covers and a reworked 76 455 HEI...

Performer intake, and 800 Cfm Edelbrock AFB...

Cheap Heddman headers for the 68-76 Cutlass fit the late B body like they were made for it, and Im running a 2 1/4" X pipe and cheap turbo mufflers...

This bomb should be about 9.99 to 1 compression so Im expecting a challenge tuning it to run on 93 pump gas with the TH400 with 10" 2500 stall converter and 2.73 open rear in this heavy 4 door...

It will be running tomorrow and were gonna find out if that old cam, crank and bearings are gonna live in the new old junk 425

I'll let ya know how it go's...

I always wanted a 425 but never had one that ran, so Im looking forward to this

Steve O

Damn it's a GOOD RUNNER

It's got 35 degrees total timing with the initial at 20ish...

Still had 3/4 tank of 87 octane in it, seems to run good on the 87 without the vacuum advance...

Gotta burn that tank off then try some Mobil 93 before I can get the tune right...

The heads have a nice port job with new 2.07/1.68 valves and polished chambers...

Its very smooth with excellent oil pressure, So far so good

defiant1

Glad it is going well so far. Keep us updated with the progress.

defiant1

A few questions for you:

How do you know/check that used crank, main and rod bearings are within tolerance?

Would you recommend the 455 over the 425 short block (all things being equal)? I have a the 425 block, but can get a 455 block pretty easily. Other than the bank angle & shorter stroke any other pros and cons?

Do you like the performer intake manifold? I will be installing a Torker.

Is the 800CFM Edelbrock a good compromise or is it a pain to tune to play nicely with the rest of your engine specs?

How is your vacuum with the motor? Any idle issues,etc.?

Thanks
d1

Steve O

Well the bearings and crank are older than me and they all looked perfect so I just cleaned up and hand honed a 455 block and put it all in there... I just kept all the bearings on the same journal they originally came on, didn't measure anything...

I saw no reason to mike or plastiguage em...

It's still got good oil pressure after multiple beatings so I assume the clearance is good

It is burning a little oil though...

Never checked the vacuum or even messed with the carb, it runs very smooth at idle... The carb is a bit rich though, it's tuned for an old 468 I had that ran a bigger cam... Im gonna try a 750 AFB with electric choke soon...

The Performer works great for me on mild street engines, I dont like the Torker, it's not as good on the bottom end and doesn't seem to be much stronger up top...

The 800 CFM Edelbrock AFB is my favorite street carb, but the 750 is fine too... Any carb thats tuned and sized right will work I like the AFB on a driver though, I think their easy to tune and they hold that tune for a long time...

The 45 degree cam can be ordered, I went with a 455 block because the .921 lifters are expensive and hard to find, I already had the good used cam and lifters so it was an easy choice there...

I may get started building a 461 short block though, It's burning oil The piston to wall clearance was .0035-.0040 hopefully the rings will break in a little better though, burned about 1 quart in 300 or so miles...

But considering except for the heads it was all just thrown together junk I had laying around Im amazed at how good it runs

Steve O

If your pistons and cylinder walls are in good shape you might just rering it and polish the crank and install new bearings...

Those A heads are good and just a little bowl porting and bigger valves will run really good...

I don't have a tach in my Ninety Eight but Id say my 425 pulls to over 5500 rpm easy...

Only 2.73 gears, I shift at 60 out of first and it burys the 85 mph speedo before I hit third and just keeps going

defiant1

Yeah, I wish I could just hone the cylinder walls, but the rust scale looks a little too deep in about 3 of my cylinders. Hell, I am just trying to get it disassembled, right now it is locked up. Got diesel fuel soaking on the pistons right now. Had a half a case of PB blaster on it already over the last 2 weeks and still no movement. Sooooo, hopefully my luck will change.

Since it looks like I will have to bore it out. Any opinion on size .030 vs. .040 vs. .060? I will assume finding oversized pistons will be the limiting factor.

I am glad you are happy with your build. I hope your oil buring issue is minimized.

d1

SBORule

You reused 40 plus year old main and rod bearings?

I thought I was cheap.

Steve O

45 years old but they really were nice along with the crank so why not

Makes up for the high dollar parts in my race motors

Steve O

Well Id go as small of an overbore as I could get away with so it could be rebuilt again...

Dont know much about available cheap 425 pistons though, I don't think they exist

I have a fresh machined 455 crank/NEW bearings and plenty of rods just need to scrounge up a block and some new pistons and get something machined right to match my new heads...

Sounds like yours is gonna need a lot of $$$ to fix...

Fastbrianman

I don't think that a quart of oil is a lot for how your motor was assembled and only driven 300 mile. I will bet that it will get better as the rings seal and you get some more miles on it. Good luck with it. Sounds like some of my old builds from my teen years. I always had a lot of fun with them.

Jaybird

The only place that I was able to locate pistons for my 425 was from Kanter. http://www.kanter.com/
Egge and Badger told me that they are not currently manufacturing them because the demand isn't there. I bought a set of Kanter pistons this past January and the engine was finally completed Friday, Aug. 26, 2011.
Besides the long time it took, I'm pleased with my engine and my builders.
You might be able to pick up a set of pistons from eBay. I went with low compression (9-1) for my build. Kanter calls those two barrel pistons.

Good luck with your build.

Jaybird

defiant1

Does anyone know what model ARP rocker studs will work with the A heads? I looked in the ARP catalogue and did not see any 3/8 x 3/8 studs listed.

I got the SBF 1.6 rockers and guide plates already.

Thanks
d1

steve e summer

I'm no lurker, just letting you know. I have 2 1965 425 that currently reside in cars. One I want to swap into my 1971 Cutlass (engine & trans has 50k~Cutlass 100k but really nice) the second motor is a 2 barrel 310hp engine that I want to build for my '65 Ninety Eight street fighter convertible. By the way, the 4 barrel 360hp 425 that I want to put in the Cutlass is the motor in the '65 convertible. My new 65 donor car has the 310hp 425. I already picked up a correct '65 4 barrel intake manifold seeing that I had two spare Rochester 4GC carbs laying around. The engine going into the Cutlass is smoothe as silk as has a whalopping amount of torque. I don't think I'm doing anything to that motor at all. But here I am looking at all you guys talking about building 425's and I too am going to be watching and listening, and wrenching an engine for some serious fun. steve e

64Rocket

Steve e
The 425 going into the Cutlass, I would at least pull the pan and timing cover. Clean the pan of the years of goo that has accumulated over the years and then install a "Cloyes" true roller timing chain. just to clean and reapir some leaks. Be sure to use the rubber mounts from the 350 on the 425. I would also use the water pump and the pulleys, alt brkt and ps pump set up from the 350, to keep the alignment all good.

Gene