My '428' is a 390!

[MetaJacko]

Hi,

Just taken my engin apart becouse the big end bearings were making noises.

Thought I'd check all the sizes etc and it seems I have a 390 at +40 not the 428 I thought I had bought

Anyway, the machine shop is telling me that there is damage to the pistons and cylinders and suggests a re bore to +60.

Is it worth instead to re-bore up to 4.13 (428 size)?

Other than a re bore and a 428 crank, what else would be needed to change this into a 428? Or in fact is it all a bit pointless and will not give me anything better other than saying 'its a 428'

Thanks

Paul

[Michael C Henry]

The 428 has the same bore as a 406.The 428 would take another crank with 3.98" stroke and special 428 flywheel and harmonic balancer.Anything you do has been done before . A prepaired 406 will scoot.But the goers require a lot of fancy parts.

[FFR428]

.080 is tough and sonic check is needed for the 390 to a 4.13 bore as some 390's will not take it that far. You can get the 428 crank or a Scat with a bigger stroke and keep the block at .060. Or you can get to the 428 + cu by using a Scat stroker crank. Or just rebuild it and be happy as you were. $$$$$ is the factor and how much you have to play with. JMO, G.

[rblong]

Now I will show my ignorance as a Ford newbie. Is there an easy way to tell a 428 from a 390 from the outside? I have read something about the external balanced 428 over the others. Will that tell the tale? Learning new stuff is a love hate thing - I love to learn, but hate to ask the question sometimes!

Bruce

[MetaJacko]

Hi,

Thanks for all the advice. I'm going to ask them to sonic check to see if I have room for 4.13 bore.

The machine shop I'm using can balance for me. But the question of going from interal to external balancing was something I wasn't too sure of.
As far as I know the 390 crank has a sort of 'nodule' to balance and the 428 balances against an off-balance flywheel

I've asked George if he has any 428 cranks but if I need to replace the fly wheel as well that pushes the cost to far I think (since I also have to add on the cost of transporting from US to UK and pay import tax on the cost including carrage!)

Bruce:
In answer to your question, The external balance is on the fly wheel. Unless the engine is not in a car you will not be able to see that! Even if you did see external balancing it dosn't mean its a 428 and not having external balancing dosn't mean its not a 428! Most of the block markings are nearly useless for definately identifying an FE as a 352, 390, 406, 428, 427 etc. So unless you can do some bore and stroke measuring you can never be sure.

I don't think i'm the first person to find out his '428' is a 390 and I bet I will not be the last!

Thanks everyone

Paul

[MetaJacko]

Hi Again,

Just a quick update.

Te dealer I bought the car off is willing to pay towards the cost of the rebuild so I need to work out the costs involved in converting from a 390 to a 428.

I assume that it involves boring to 4.13
putting in a 428 crank and pistons
replacing fly wheel with 428 version.

I beleve it should be possible to sleeve the block if it cannot go to 4.13 bore.

anything else I have forgotten?

Thanks

Paul

[Clois Harlan]

Hey Paul,

I have ran a 428 bored .060 over and I had all sorts of problems, primarily heat. I have a friend that is very happy with his 390 PI engine and it has plenty of power in his Cobra.

Unless you intend to race your engine I would either find a true 428 CJ or find a good 390 that can be bored out to .030 over and use most of the parts you have. I am not a fan of overboring an engine.

Someone help me here, isn't a 390 block that uses a 428 crank a 410 cu in engine that was used by Mercury's racing teams in NASCAR during the early 70's? I would think a good 390 might be much easier and cheaper to find in Europe than a 428.

Good Luck with what ever you decide to do! Keep us posted.

[MetaJacko]

Hi Clois,

Yes a 390 with a 428 crank is 410ci. (Don't know about NASCAR racing though)

I guess it all comes down to cost. I was planning on putting in a new cam with some roller tipped rockers and have some porting and polishing done.

I suppose when it comes down to it, that would be a better way of improving the engine instead of getting 'fixated' on it not being a 428.

+60 on a 4.13 bore (4.19) is quite a lot. I'm not suprised it may have gave problems. +60 on a 390 should be a lot more reliable since there should still be quite a lot of wall left. Actually, I'm just thinking, the numbers I was given was, it is currently 4.0866 and they want to take it to 4.10, thats a +50 surely! +60 would be 4.11

Oh well, im sure it will all make sense eventually

Paul

[MetaJacko]

Hi,

Another update!

I've just been advised by my machine shopt that it would not be a good idea to bore to 4.13!

So I think I'll stick with just boring enough to clean up, put in some new pistons, bearings etc.

I think I'll hot it up a bit with a new cam and rocker gear along with some porting, polishing and balencing.

I was thinking of Comp Cams 282S grind with dove roller tipped rockers, anyone had any experiance with these?

Paul

[Timmy]

I’m rebuilding my 390 bored .030 over next month. I'm going with the below cam

CraneCam 10:1 compression (Been described as a CJ cam on steroids)
Part# 343801
Grind# H-278-2
Gross Valve Lift In. 0.548 Ex. 0.560
Duration At 0.004 Tappet Lift In. 278 Ex. 290
Intake open 26 close 72
Exhaust open 80 close 30
Duration at 0.05 In. 222 Ex. 234
Lobe Separation 114

[Adrian472]

Hi Paul
Sorry to hear about your troubles. I know a man in the uk that has a couple of 390 and 428 blocks cranks etc. If you want his number email me and i will send it to you.

all the best

Adrian

[wtenukl]

Hi Paul,

I too was sold a bill of goods when the dealer told me it was a 428 and it turned out to be a 390 bored .030 over. I was having some changes made to the engine and that's how I found out. So, like many people have suggested, I'm going to be content with my 390. I had new aluminum heads put in, a Comp cam, forged pistons, raised my compression up to 10:1, and now(as if the engine wasn't powerful enough), the car really scoots now. I have no overheating problems and plenty of power.

I share in your dissapointment though. I know how you feel.

Take care

Todd

[Michael C Henry]

As I remember the 410 cu in was a Mercury combination.Ford and Mercury all had FEs that would go .They had better than average parts.They make even better after market parts now.The thing is any combination you go with will need the engine prepaired for racing .Like clearenceing ,decking ,align bore,oiling system mods etc. and ballance .Production engines used to be built close to design specifications and relied on run in wear to make everything fit. But most important is make run on pump gas.

[MetaJacko]

Hi,

Well I'm feeling a bit happier with my lot now!
I've been talking to George and I'm going with his advice on cam and rocker assembly. (Comp Cam 282S and Dove roller tipped rockers) He is suggesting it may be an idea to put ali heads on but they are expensive and I'm not sure if that would be worth it. My machine shop can port, polish, deck or whatever my current heads for quite a lot less.

Thanks

Paul

[Scout]

Hi,

Can anyone tell me where to find the casting code on a 428 block?

Thanks,

Matt

[MetaJacko]

Hi,

As far as I know, there are three places that give you numbers.

1) on front, often says something like 66 352 and you get the 352 number on just about any FE

2) on Back it will give the a block number EG 390 but this doesn't mean its a 390!

3) on side near the bottom something like C6AE-F (I made that code up)
This will help decoding it:
http://www.classicmustang.com/decoding_part_numbers.htm

If you lucky there is a metal tag under the dizzy I think (not on mine though ) with more detailed info

Hope that helps, I'm not too sure there is any number that definately identifies an FE as a specific engine (428CJ, 427SO etc)
except maybe the metal tag if you have it.

Good luck

Paul

[FFR428]

And the 410 was a Mercury offering in 65-66 only. Kinda rare to. G.

[Michael C Henry]

The heads will make one of the biggest differences . The engine is a package and if any part isn't up to the task, that becomes the limitter . Most componets have a designed operating range heads ,cam, intake,exhaust .I once had a 406 with different parts It wasn't that good at any one rpm range ..Also with a 428 you get a longer stroke for more torque but you trade rpm potential.It's all your descion, performance ,releiablity, expense.Weigh all elements because you have to live with the outcome.You don't want to redo this again.

[ruslow]

One of the fastest ways that I found to fiure out if it a 3.98 stroke is to stick an pencil down the spark plug hole and measure the distance of travel.But use a new pencil so not to lose it in the cyl! STan
And yes the 410 is a stoke 390 bore with a 428 crank.YOu can look at the crank and find the numbers on it it need to read atleast a 1U that is the standard 428 or 1UA 428CJ,1UAB or 1Ub for the 428 SCJ.

[My427stang]

428 / 428 PI/ 428CJ / 410 - 1UB, or 1U

428 SCJ - 1UA

390 - Usually 2T or 2U I think, been a while

However only way to know what you have is by crank number and bore size. You can cheat on stroke through plug hole, but you still wont know bore size.

However, I would say this, if I had a 390, I'd build a 390, if I had a 428 I'd build a 428. The money it costs to bore a 390 to 4.13 (assuming you have a block that can take it) and buy the crank and pistons, would be MUCH better spent on a set of good heads ported to your intended RPM range.

There is no doubt in my mind a good breathing 390 will eat a stock headed 428 for lunch.

However I have one exception to the above rule, if you have the dough-re-mi, stroke the HECK out of the 390 with a SCAT crank , leave the bore stock, AND do the heads and make some serious street power, but the 428 stuff is pricy and not worth that much power-wise

CJ's eat 390's for lunch, but only because of the heads, the exhaust manifolds, and the intake being significantly better designed, the stroke really isnt that much of a difference to change the behavior of the motor. Airflow is where its at