Valves hitting heads

D

diiulio

Junior Member
Ok, I am finally getting my 8ba together. I have an Ford 8ba, with stock valves, stock crank, Isky 400jr cam, and EAB heads.

I just finished adjusting the valves at .018" on both intake and exhaust. The cam and crank gears only go on one way and I lined the dots/hash marks up.

So, my problem is I rested one head on at a time, put three bolts in loose, and then cycled the crank a bunch of times. I put no gasket on. The head would lift when one of the valves were up for each cylinder.

How do I figure out what the conflict is?
Should I just bring my block and heads to a machine shop and let them correct? I can't machine the heads any ways.
My other option may be to just buy some aftermarket aluminum heads, but not sure I won't have clearance issues there too.

Anybody in VA area is welcome to swing by if you like.
Jason
 
Now you have a new issue as you may have bent some valves. Valves bend very easily, so I would be checking that as well. It is not uncommon to have to cut valve clearance for a high lift cam.
 
You think I would have bent valves with the bolts in loose? I still had 1/4" at least to the bolt head. The heads were never restricted by the bolts.
 
But the valves had to be lifting the heads. I really have no idea if it would bend them or not. But valves bend very easy, it doesn't take much at all. Just something to check.
 
Just thinking here, but I would space the heads up a safe distance, washers or something under the four corners of the heads. Then use clay or foil or whatever on top of the valves and the piston. Turn it over and measure the clay (whatever) to determine the clearances.
 
The valves are hitting the head.
Think about it, stock cam some where around .330" lift, 400jr advertised lift .400".
Measure the lift at the valve with a 6" scale & then the chamber to get some idea about clearance.
Un-milled stock EAB heads have a lot of piston clearance. The heads need the work to clear the valves.
A MAX-1 with .364" lift doesn't have lift issues.
 
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Just put a dab of grease around each valve at 90 degree locations(4 places per valve) and repeat your loose head test. The transferred grease will give you a clue. Often a hand grinder can correct the problem if not too serious.

A better solution would be to loose the 400jr. Just my opinion.
 
I'll try the grease on the valves.

JWL,
What is your reason for losing the 400jr? You don't like the cam? What do you prefer, L-100 or max1?
 
The EAB heads are pretty tight heads for stock heads, I use a lot of them, They won't stand much milling before the pistons hit, and of course 400 lift cam is problem with the EAB heads. You won't hurt the valves by just laying them on a few studs and letting the valve push the heads up. To make it easier I always do my valve before installing the pistons and check valve for clearance. BUT, once you find out how much the valves are lifting the heads that's easy to fix. Lay a head gasket on the heads and scribe a mark around the top of the head valve pockets, Take the heads to a machine shop and have them set the heads up at a 5 anglel on a Bridge Port and use a cutter I think around 1-7/8 and cut down next to the scribe mark down the depth you want, You'll only taking an eye brow out up in that radius. Of course you want to check piston clearance, if the clearance is zero with no gaskets the gaskets are usually .050 so that's perfect. Walt
 
I don't like the 400jr for any street application because of the wear issues and noise. I do like it for a short track race engine. What is better? It depends on your reason for changing from a stock cam-------do you desire less low end torque but more top end power? Is this change only for the purpose of introducing a "salty" idle?? What are you trying to accomplish? What is the overall goal?
 
Thank you Walt.

JWL,
My goal is streetable car with a nice lumpy sound. Honestly, if I wanted high HP or torque I wouldn't be using a flatty, I would have just kept the Olds 303 that was in it. I am not racing the car or doing anything other than enjoying it. I based the cam on a few books I had purchased and some posts here on Ford Barn. I was torn between the Max1 and 400jr. I have zero experience with flatheads and don't really know anybody with flatheads. I can't remember why I chose the 400jr over the max1, but it may have been Mike Bishop's book.

This is going in a 30 Model A coupe with no hood or fenders. I had an Olds 303 rocket in it, but loved the traditional aspect of the flatty, the look, and the sound. I am also putting a T5 behind the flatty.

Right or wrong I have the 400jr in it now. Is it really that bad that you wouldn't use it? This is the first time I have heard negatives on this cam.
 
Not for the faint of heart, and not for the street! This famous Isky 400 Jr. grind camshaft is full race, competition only and is recommended only for the experienced flathead V8 racer.
Flatheads have a sound of there own stock.
When I was young what we did was pull the vacuum line off the wipers and cruise the hang out.
 
Hi Jason, the amount of "space" needed to solve the issue is fairly easy to figure out??

Just shim the head equally all around until the valves clear, start with a smaller thickness shim. We do this occasionally on some higher-end builds using valve spring shims. You could use single sheets of newspaper (stacked), aluminum foil (also stacked), etc.

Also remember you will have the entire gasket thickness on your side! Below is a shot of some machined Edelbrock's, it wasn't for clearance, it was basically done to enlarge the chamber volumes some.

The other option is flycut the heads, also relatively easy. Nice to have an accurate amount though?

That valve lash is a bit on the loose side for me for a "streeter"!

Thanks, Gary in N.Y.

P.S. I also agree with John's and the other posts above, cam is slightly on the large side. If you're looking for the "sound" Comp's new "Thumper Series" will deliver. I've listened to a couple now, they sound excellent.
 

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The problem with the 400jr in your application is that the engine is basically stock (if I'm reading your OP correctly) except for the cam. That's not really, as stated by everyone else, the application for this cam. It is intended for a bored and stroked (larger cubic inches) race type engine.
 
Thanks everyone for the input.

I thought .018" was high also, I was thinking .014" based on what I read. I even called Isky to confirm and they said 'yes, .018 inch'.

I would hope they know what they are doing, do you think I should bring it down to .016"?

I want to see how this engine runs before just tossing the cam. I'll give it a shot, if it doesn't work out I will get a different cam.
 
No, do not deviate from the Isky specified clearance. Although .002 change isn't much the cam is ground with a "take-up" ramp designed for .018. If noise isn't a issue and if moderate miles of travel are planned the shortcomings won't bother you.
 
You obviously never read any threads of mine, because i definitely would NOT run a 400jr on the street. That's why I recommend the L-100. It has the same efective sound as the 400 jr, less lift, needs less spring pressure to operate. I asked you in your PM what springs you were using??
 
Listen to the wise old heads. JWL and Ol Ron have futzed with flatheads all their lives, and if they recommend don't do it, trust me, don't do it. The first time you stall at the traffic lights, then get it started and have to use a lot of revs to take off, you WILL be cursing your decision. 400jr is for big inch flatties with lots of fuel flow, porting etc.
 
Why ask the cam question you have already made the decision. You also don't want to change any of your decisions so carry on and live with the results.Don't say you weren't advised. :)

R
 
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