Ok, since I picked up the 400 on Friday, Ive already started tearing it down. Ive found some good things, and as expected, some not so good things.
It was interesting in that in taking off the heads I discovered that prior people had drilled holes in the side of the heads (likely for mounting assessories), and it ended up going into the cylinder head bolts. I suspect that they used the wrong depth head bolts or they simply went too deep in their drilling. Either way, those bolts will need to be replaced.
For the push rods, Ive seen two different types of pushrods used. One is long straight rod with just the oil hole in the tips, and the other rod has ball ends. Not sure, but I suspect that a few rods were replaced sometime in the past 40 yrs. For me it probably makes sense to replace them all and go to one type.
For the pistons, the wear/carbon build up was minimal, and I didnt note any .20, .30s etc on the piston tops, so Im wondering if this block has never been bored.
The cylinders looked pretty good, no obvious channels, or major ridge issues, although on the top area of the block surface area, I did note that the circular area looked a bit oblong in some cylinders. Is that normal?
If the piston is all the way to the top of its rotation, you can see its not perfectly round, which makes me wonder if someone was going to bore it, and rounded a little of the top, or was it just made that way? Not sure if that affects performance or not.
*If someone could post some good and bad pics of the top surface area completely surrounding the piston, I might be able to compare. Otherwise, I suspect Ill be taking it to the machine shop and get a professional opinion on the condition. If its never been bored, then I would suspect no problem in boring a bit, slightly bigger pistons and reassemble.
The cam has the usual varnish on it, but I didnt see any major flat spots or eroded lobes. Im still looking at replacing the cam anyway, but just trying to guage what type of life this engine has had.
The valve lifters Ive been able to remove so far look ok, just a bit of varnish, but no concave sections. If Im replacing the cam anyway, it makes sense to replace lifters at the same time if part of a kit.
From what I can tell, it looks like the engine was probably used within the last year or two as the cylinder walls still had oil, and the coolant passages still had proper colored green coolant in them. My guess is that someone simply pulled the motor to replace it with another one, and then set it aside. But at least they knew enough to tape off the intake ports, lubed the cylinder walls, put coolant in the passage ways, etc..
We are walking down the same path! I just picked up a 400 long block, actully it was everything but the intake and cam. The heads were off and the pistons removed, only the crank was "installed" on the block. I noticed the same oblong areas on the cylinders.
So I think we are "in the same boat" and OK. the only things I noticed was a few rods were bent and the water jacket and passages on mine are rusted some. But I have been told a hot tank on it will clean it like new.
Lets keep each other informed of progress, cause I have alot of questions also.
The pics are of the obling areas on the forword and rear most cylinders
In looking at the pics, it looks as though everyone has the same setting, so I question if perhaps what Im looking at is normal.
On the pics:
BZs, that last pic..right cylinder 9 oclock If6was9..2nd pic, 4 oclock 2nd clyinder from right, far left cylinder 4 oclock 8point...bottom cylinder midnight..
Are those areas just the way they were originally bored from the plant, or, are those slightly off round areas from where someone bored and it wandered on them?
Mine definetly looks comparable to the before pics you guys have, nowhere near as clean as the afters...yet..heh
Thanks for the pics.. that makes me feel better that mine is rebuildable.
My question at this point is, do I still completely tear down to bare block and reassemble with the new/restored parts, or go from its current state (its completely dissasembled except for pistons and crank).
My wallet says go forward from here, but, my gutt says, take off the pistons and crank as well, replace the bearings, and go forward fresh. Its already apart, so nows the time to do it right.
Ive already started pricing out parts: -all new/same rods in a set -main, cam bearings -cam & lifters -gaskets -heads bolts that were drilled into in error. ...not to mention the intake, heads and carb I was going to need to replace anyway.
On a related note... since this is the setup Im going for, Id appreciate some cam recommendations:
block: 9790071 pistons: current installed stock if bore ok, otherwise, .10, .20, .30 depending on what shop would think. heads: 62 intake 9794234 (4v) carb: 7029268 (Qjet 4v)
Im not shooting for a racing car, just something that would be considered close to stock for 68-69 on the 68/69 400-4v Firebird.
BZs, that last pic..right cylinder 9 oclock If6was9..2nd pic, 4 oclock 2nd clyinder from right, far left cylinder 4 oclock 8point...bottom cylinder midnight..
Those are the "eyebrows." They are there for valve clearance. And, yes that is normal.
-=>Lee<=- Due to budget constraints the "light at the end of the tunnel" has been turned off!
My wallet says go forward from here, but, my gutt says, take off the pistons and crank as well, replace the bearings, and go forward fresh. Its already apart, so nows the time to do it right.
I have tossed around the idea also. Do you have a running engine in the car already? If so I would wait and do it all new. to get it all put together, and then the swap it in the car itself is no simple task, hang all the accessories plumb all the hoses.....see what I am getting at. To run it and findout in 2000 miles it has to come out would be a hard pill to swallow. My .02
Mushroombert... eyebrows? I know on the pistons the indentations are the eyebrows, but I didnt know that the cylinder walls themselves have eyebrows for valve clearance?.. I would have thought if that was true then all of the cylinders would have had them..? ..hmmm...
Bz.. yeah, I currently have a running 350 in the car, and plan on leaving it in till Im to the point of swapping over. My goal was to take my time, and build the engine right, once, ...then swap out the 350 and sell it to help recoup some costs (if theres any market for a 69 YE 350..)
Yes, the chamfer at the top of the cylinders are factory. They improve air flow into the chamber when using large valve heads. The smaller the bore, the larger they are.
8point's is a 67 block. BZs68bird's is a 68 and up.
Why do some heads list multiple hp for the same ci engine?
Ex: 1968 62 heads, lists hps of: 330,335,350,360...with the AT.
Other then cam, carb, or if its ram air, is there something else thats affecting the hp?
If I have the 9790071 400 block, 62 heads, stock intake (9794234) & Qjet, AT, what can I expect for hp? The Firebirds listed 330 for that type of setup, so is that what I would assume for ending hp?
..hm..what was the standard 400-4v heads for an Oct 68, 69 model Firebird? Wasnt it the 62 heads? ..or were they 16s, or something else?..
Like I said, seems we are working on the same style project. I found this site that lists alot of head info, mainly what I see is valve size and chamber cc'c make up the differences in HP, add a different cam profile and that must account for the 5 to 10 HP differences
Mushroombert... eyebrows? I know on the pistons the indentations are the eyebrows, but I didnt know that the cylinder walls themselves have eyebrows for valve clearance?.. I would have thought if that was true then all of the cylinders would have had them..? ..hmmm...
I've always called them eyebrows, and the ones in the top of the piston "valve notches." Here's a pic of them on my 350.
-=>Lee<=- Due to budget constraints the "light at the end of the tunnel" has been turned off!
Different cams made the differences in the hp ratings between engines with the same heads. The ram airs run into a whole host of different parts to make the hp they advertised. My basically stock engine with 68-16 heads and aftermarket cam through my muncie made 300hp on a chasis dyno before it dropped like a rock at 4900 rpms with bad valve springs. At 10-15% loss through the drivetrain it works out to about 330 to 350hp at the flywheel. A little extra money and some good decisions on the right parts and a well built 400 should make 400hp.
I'm also in the process right now of rebuilding my 400. Again. There's definately a learning curve in the process. Hopefully this one will be better than the previous attempts. I'm already starting with better parts and I'm doing a lot more measuring and check up of my own on the machine work that I'm having done.
Whether it's 2bbl or 4bbl will make a big difference as well as cam. I read that the only difference between the Firebird 330hp and GTO 350hp was a restriction placed on it. I don't know remember what that restriction was.
I don't know what stock intake that's from but I would think that setup would give you 330hp if it's a 4bbl.
The exhaust system will also effect hp. I don't think there was a difference on stock exhaust but I'm not sure on that. Adding headers or different muffler, pipe size, etc can make a difference. I think 2.5" pipe is optimal on the 400.
Relating to what Firebob said on hp, back then the 330hp was figured from the flywheel and not the back wheels.
Last edited by Sheri; 04/14/0902:00 PM. Reason: added info
"An ignorant man thinks he knows everything, a wise man knows he doesn't."
As easy as it is to get caught in the never ending stream of options for engines, (bigger cams, rollers, alum intakes, head changes, etc, etc.), Im really trying to recreate, if its possible, what my engine/car would have been if the person who bought this 350-vert had decided to get the 400 option instead. My whole goal when I started was to get a 69 Firebird 400 vert.
Given Ive now got the 9790071 block, the other parts Im now going after include 62 or 16 heads, 9794234 intake, & the 7029268 Qjet.
I may deviate as I go along, like the alum radiator I already have, or other engine aesthetics to spice it up, but Im going to try to stay pretty close to stock for engine components, and swapping over from the current YE-350/2v for parts as I need to (pulleys, alternator, etc, etc.). Then I hope to sell off the 350 and the extra heads, etc I accumulated in the process.
According to my cost estimates, by the time Im done, Ill have about $1800 tied into the engine, (not including any machine shop work), with the bulk of the labor being myself. But when done, I should have a freshly rebuilt, fairly close to original, 69 400. Im not planning on racing or ripping it up, but I do want to do the rebuild once, hopefully correctly, and not have to worry about it for years...
Then I can go onto rebuilding the front end (I have the parts, but got sidetracked by the engine), then bodywork...and remaining little stuff.., then that should cover it. I gave myself 3-5 years, and right now Im at year two. Ive already covered interior, electrical, brakes, fuel, rear suspension, and theres little doubt Ill likely revisit some of them again...(you cant own an old car and not keep redoing things...)
Anyway, I appeciate the info/knowledge, and Im sure Ill be asking for more help as I wander through this..
I dont think its going to cost $1800 for a set of 16 or 62 heads.. Ive been seing them go for $200-$400 a set, depending on condition, whats been done to them, etc. Shipping is the problem as it will likely cost about $100 to ship them.
In a mathematical sense, wouldnt the correct answer be... 14 heads? heh.. It took me a second to catch it. (Boy my "heads" spinning on engine stuff lately.. (pun intended)
I guess my question is, are they the same heads, just different applications?...or..production locations?... Most everything Ive read has the 16s or 62s as the main Firebird 400 heads for 68/69. But I seem to recall the 48s were RAIII heads as well..?
62 and 16 CORES go for $300+ a set unless they are rusted hunks of junk. You'll have a hard time finding any popular # big valve heads that have had good work done to them for less than $600 unless someone is dumping them.
I put $700 into a set of original to the car #16 heads. If I had to buy cores I'd have been out $1K. And that is a nothing crazy but all good parts build, with professional machine work, Ferrea stainless valves, hardened seats, new guides, correct springs and all geometries properly calculated.
Heads aren't cheap, but without a good set your car has asthma.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
62 and 16 CORES go for $300+ a set unless they are rusted hunks of junk. You'll have a hard time finding any popular # big valve heads that have had good work done to them for less than $600 unless someone is dumping them.
I agree. Thats about the pricing Ive been seeing. I know that after paying that core price Ill have to drop another chunk to get them ready for installation. As with all old parts, first comes just getting the right part, then comes the restoration...unless youre lucky enough to find parts that have already been done. Seems those parts are quickly snatched up by the GTO crowd..
I have a set of #62s at the machinist's. I have to pick them up and settle up (blasting and inspection) before I offer them up. That comes down to time...no way I can get downriver during the workweek with my job schedule.
Vikki 1969 Goldenrod Yellow / black 400 convertible numbers matching
#48 heads (as posted elsewhere) had heavy-duty dual springs where the #62 used standard-duty dual springs.
Both #62 and #48 are rumored to have been used on Ram Air 3 (or 400 HO) motors. This, however, may not be accurate.
#48 heads were also used on non-HO 400 and 350 4-Bbl engines when fitted with a manual transmission.
So, #48 does not mean Ram Air (or HO) only.
Q, I've heard that about the #48 heads as well. I wish my convertible had it's original engine to verify the rumor. That's one of the reasons I put #48 heads on my 'bird last year. The other reason was having a miss-matched #16 & #62 head on the block.
