Found an older guy who has this motor and transmission that took as payment for a job. It's been sitting in his garage ever since. Here is all the information I have so far. Its a YH engine. The only other number from the block he gave me is 153146. I asked about the heads and he emailed that it has 16 heads and he couldn't read all the date code only D15.... I think it will be a high compression engine. Is there anything you guys can tell me about this engine or what I should look for? He has never heard it run.
YH with #16 heads could be a 375 HP 428 from '68. YH is also a '70 455, but it would have #15 heads.
Ask for the date code by the distributor and the casting number at the back of the passenger side head.
If it's got original hardware inside, it's a pretty decent motor. It will most likely have a 4-bolt block with 2-bolt caps. (All 428 blocks were drilled for 4-bolt mains, but only the 390 HP version had the 4-bolt caps.)
Thanks Quenton. I was hoping you would chime in here. I am going to run out there tomorrow afternoon to take a look at it. Should it have 428 cast into the side of the block? If you don't mind I will post the date codes tomorrow when I get home. I printed out all the block and head code sheets from Pontiac Power. Maybe I will get lucky and find a diamond in the rough. He actually said it is a 428 HO. Worth going to take a look at.
There are a number of factors that will influence everyone's opinion about that, including mine. Everyone will have an opinion, and most will differ.
My 428 wears #64 heads. I've got flat-topped pistons and a zero deck, though.
There's so many good choices because you can get dished pistons of almost any dish volume that will allow you to run almost any large-valve head. I am pretty sure that most everyone would advise running large valves, with one caveat. If you're running highway gears, such as mid 2 gears, you would do just fine with small exhaust valves and you'd find you have a very decent amount of low-RPM torque.
Other factors would be what your goals and budget are. With an unlimited budget, 87cc Edelbrock heads would be a blast on a 428.
For a limited budget and with modest performance goals, the following heads are all approximately equal and will differ only in core price:
#12, #13, #16, #48, #62, #64, #96.
Then there are the less-realistic choices:
#722, #614.
OK ... I'm kidding about those two, though it would be nice to see what Pontiac would have achieved with a Ram Air 6. (That would be a 428 with #722 heads.)
Well I can't see investing money into the small valve heads. So the shopping continues. Large valve heads are now on the top of the list. Thanks again for all the help on this. When I first rubbed all the crud off the heads I thought they were 48's for a moment. This car has a 3.42 gear set in a 8.5" rear end. My budget isn't squeeky tight but a long way from unlimited. Like most I want the biggest bang for the buck.
Well this is what I would like to see. I don't want it to be a fire breathing moster but want respectable power. A relatively smooth idle and be able to run it on pump gas.
To get great performance and good street and pump manners, the obvious attention to detail is in the combination of heads, cam, intake & exhaust. The 428 was one of Pontiacs best stock combinations and you'd have a really hard time doing a better job than they did.
Without an idea of your budget, the following is simply offered as my opinion about how it could be done. This is just scratching the surface.
First, a quick thought about compression ratio ... there's no magic number for the optimum static compression ratio. Consider what gas you want to pay for every time you fill up. The quench and dynamic compression - which are a function of the heads, piston and cam together - will determine how much static compression you can get away with. Here are some of the basic contributors:
Heads: The chamber volume (cc's) will determine the static compression ratio with the piston sweep and dish volume.
Cam: The ICE (Intake closing event) will determine the dynamic pressure in the cylinder on the compression stroke.
Pistons: The dish volume (cc's) will influence the static compression ratio.
Block: The decking will influence the amount of quench volume (discussed recently) which can lead to pre-ignition vs. the dynamic compression.
OK ... so what would that mean for you?
Heads: Big valve heads such as #62 and #13 heads have larger (relatively) 75 cc chambers than #16 (1968) #48, and #12, which are all good starting points. A decent rebuild and - if you want - some basic bowl work, blending and some unshrouding of the valves would do fine. Since you have a 428, the #62 heads would be age-appropriate, but in no way do they differ from #13 heads. The others would require a few more cc's of dishing on the pistons.
Cam: What you probably have is the "067." (You can look it up in the 68 or 69 service manual.) The "744" is one of my personal favorites for a 428 with a manual trans and 3.55 gears. That's about the same as the Summit K2802. For the right cam choice, though, the rest of your car's set up is pretty important. There's no one right answer. Gears, trans choices and the stall speed of your converter will all be factors.
Intake: The factory cast iron is pretty hard to beat. If you want to go lighter, the Edelbrock Performer or Performer RPM are pretty good.
Exhaust: Go for the R.A.R.E Long Branch manifolds.
Other details you might want to think about ...
Block work: Your 2-bolt mains are fine. You can add 4-bolt main caps since the block is drilled for them, but use main studs if you do. (You really won’t need them - it's just my brand of over-kill.) Deck the block to -.000 to -.005. Block prep should also include align-boring if you re-cap the block and boring & honing (as always with torque plates installed).
Crank: Chamfer all the oil holes.
Rods should be fitted with ARP bolts & re-sized. Cast rods are great for street performance.
Pistons: Forged is really the only way to go. The dishing will reflect your choice in heads. If you go for #13 or #62, you'll have to size your piston dish AFTER you cc the heads. If you go for larger chamber heads (of which there are many) then you will need less dishing in your pistons. You will want about 95cc of total volume between the piston dish and head chamber, assuming that you zero deck and use a .039 crushed gasket thickness. Why 95? Well, it works out with the ICE of the 2802 cam to give about 170 PSI dynamic compression. That's in the range of 93 octane gas and proper tuning and distributor curving.
Carb: Rochester Q-Jet. Buy Cliff Ruggle's Q-Jet book. If you want to have him rebuild your carb, make sure you send it to him three months ago.
Distributor: I’ve used Unilite distributors for years, and I will always recommend one. A points distributor is perfectly fine.
Did I mention that this is just my opinion? I built my 428 just like that, but with #64 heads (87cc) because I used pistons with no dishing.
I was not planning on straying too far from stock. After all 360 hp should push the bird down the road nicely. The information you gave is exactly what guys like me need. You have already built an engine like this! I had already made my mind up about the long branch manifolds. I do remember the quench discussion and made notes on that. Head selection and how to put it all together without ending up with mismatched parts is inportant to me. I am starting my lisst for the machine shop. Thank you again for your time. I will be out in the pole barn today tearing the engine down. I have an edelbrock performer on the 350 in the car now and the engine came with the factory cast iron one. I plan on adding the ram air pans to the car so I need to know if the edelbrock manifold is the same height as the factory one? I am leaning toward the fastory one. The purist are getting to me! I also have edelbrock carb in 600 and 750cfm. Which would be the right size for a build like this?
I am gratefull for all the advice. Is there a specific carb model I should be looking for?
Motor is torn down. I don't think it had ever been rebuilt as I found no oversized markings on any of the bearings or pistons. It is in remarkably good shape with not much wear on any of bearings and the cylinders are ridge free and not marked at all. I did find a little scoring on the rear main but nothing to bad. The cam that came out of it has 066 on it. Can anyone recommend a good machine shop in this area?
Spoke with him today for a few minutesand he has lots of suggetions. Also said they have another 428 in the shop right now. I was originally planning on doing all the reassembly myself but may end up letting him put the short block together and degree the cam. I think we will get along fine. He knew who you were as soon as I mentioned your name. Just loaded all the parts in my truck so I will meet him tomorrow. I used to live less than a mile from his shop and never knew it was there. I'm still undecided about keeping or selling the 350 that is in the car now.
If it's got original hardware inside, it's a pretty decent motor. It will most likely have a 4-bolt block with 2-bolt caps. (All 428 blocks were drilled for 4-bolt mains, but only the 390 HP version had the 4-bolt caps.)
not all 428s are drilled for 4bolt mains.. i bought 2 of them and one is the other isnt.
Where are you at with this build. I am building a 69 428 for my car using 16 heads. The motor is in assembly stage. I went with a comp cam extreme energy 268 cam, 224,230 but on a 112 lob separation. I went with a 9.5:1 compression ratio. I have been kicking around using the long branch manifolds. Not 100% sure I can pop for that, but would like to. Do you know what you have in the build at this point? I am up around $2000 for parts and machining. Have more in the block and heads. This is getting expensive, but I think it will be worth it.
I will be going over to see the builder today to drop off the rest of the parts (valley cover and windage tray). I will take a piece of paper and get the specs. I had a pair of already done 62 heads so my bill will probably not be as high as yours.
Just got back fromt the builders. He has the short block together and is really only waiting on an oil pan. Should be done in a couple days. I did find out that he is using an Isky 281 cam and said the compression should be around 9 to 1 when its all back together.
He hasn't put it through his computer program yet but seems to think we should be right around 400hp or so. Which is just fine for me. Don't want an all out race car.
This is a fair amount of cam with narrow lob seperation. I doubt that it would work with an auto trans due to vacume issues. My cam is a bit more mild, but I am runing an auto trans.
Looks pretty good. I would question the recommended springs though. Pressures are ok but looks like you have to shim them to get the right installed height. I'm surprised with all those shims you don't get coil bind earlier than .980. Must be pretty thin wire gauge. And I hear you gotta watch out with the dampeners. They say the ends will dig into the spring seat at the bottom.
Just saw the engine. The springs are all shimmed up to correct height. He was showing me the how different the shimming was from one rocker to the next. Didn't ask about dampners.