427 Intake Manifold

[Eljaro]

My 427 top oiler with Dove F5 aluminum heads and dove aluminum rockers is fine , but I have had already 3 broken (the cup at the top) pushrods I have found out that the pushrods were touching the bottom side of the hole in the intake manifold and hitting the ball on the adjuster screw of the rocker off axis, which is probably the reason for the cups of the pushrods to brake.
I have drilled a larger pushrod hole in the manifold(which seems to be a Blue Thunder ), inserted a tube and welded top and bottom. The aluminum of the manifold is very porous and difficult to weld , leaving allways some pore for water to seep into the engine.
Looks like after so much welding the manifold is starting to look ugly and starting to deform.
So here comes the question: the blue thunder manifold I have has 1.22"x2.25" ports. The edelbrock performer RPM FE manifold has 1.06"x1.75" ports and the size of the intake ports in the heads is 1.35"x2.05".
Will the Edelbrock (which is my choice because of price and availability) with this mismatch in port size work fine with those heads?
I do prefer low end torque to top end power , although 6000+ rpm can be seen very often in my outings.
Any suggestion from any of you?

[SCOBRAC]

Yes. But you should get a die grinder an match port the manifold. I thought Edelbrock made an FE manifold with bigger ports. Maybe that would be better for you. www.summitracing.com

[SCOBRAC]

It doesn't give the Edelbrock port dimensions. You might call them...

http://store.summitracing.com/defaul...ntake&x=26&y=9

I have a weiand dual quad intake that has 1.35 x 2.25 ports in new condition you can have pretty cheap if you want one that matches.

[Eljaro]

grinding the ports is exactly what I thought needed be done to match the manifold to the heads. That is quite a job , so I will try once more to fix the Blue Thunder. If it doesn´t work , I´ll get an Edelbrock and do the port matching and grinding. Thanks for your offer for a dual quad, but that implies to get an additional Holley plus all the linkage.
I have too many variables in the rebuild engine , and I do not want to add another one before seeing how everything works together. Thank for your tips, michael

[rritchey]

Just a suggestion.... try looking up the port sizes on the new Ebock Victor FE intake. I have heard good reports about it.

[JBAIRD]

Try the Victor FE it's the best. We have them in Stock as well $695.00 Keith Craft Motorsports. 9720 578-3550.

[concobra]

Eljaro

Regarding the pushrods hitting the manifold. Your problem is common. The intake valve lifter is offset towards the center of the intake port and this causes the pushrods to set at an angle through the pushrod hole in the intake manifold. I had the same problem but on the other side of the pushrod hole. This is because I used offset roller lifters and .125" offset roller rockers. This caused my pushrods to hit the outside of the hole. Here is a recommendation to eliminate this problem.

1. Drill out the pushrod hole to .875"
2. Press into hole holes a plug that creates a .002" interference fit. (Before doing so coat the plug and hole with a good high temp. epoxy like JB weld)
3. Allow a day for the epoxy to dry.
4. Assemble the manifold to the engine.
5. Using all thread make a pointed end and thread into each rocker arm until the point makes contact with the plug. (You may have to adjust the rocker height in order to get the pointer to hit the plug in the center. I am talking about the center based on the distance from the intake to head mating surface and not the side to side center.)
6. Punch a mark where the pointed makes contact with the plug. This will be the correct side to side location your pushrod will need to be in.
7. Drill a .625" hole for each punch mark and your done.
No welding is needed.

Another possible cause is your pushrod cup / adjusting ball may not be getting enough lubricant and galling then braking. Check to see if there is blueing in the cups.

[Bubb Rubb]

Originally posted by JBAIRD


Try the Victor FE it's the best. We have them in Stock as well $695.00 Keith Craft Motorsports. 9720 578-3550.

Best for what? The Performer RPM is better for street and some track use. The Victor FE is better for midrange and high rpm horsepower. A dual quad manifold is even better for high rpm power, and for wow factor.

You are advertising these for $500 elsewhere, by the way

[Eljaro]

Thanks for the Victor Manif. suggestion, but that is not a manifold for everyday use nor to achieve low end torque. Edelbrock say so anouncing a 5500-8500 rpm range.
My problem with the Blue Thunder was that a pore was seeping water from the water passage to the inlet pushrod hole of cyl. #1 in the manifold.
Drilling and sleeving and welding did not help, maybe because the welder was not up to the job.
I did move one pushrod hole by drilling slightly offset toward the head and sleeving, but had a problem with the pushrod touching the hole at the bottom towards the center of the engine.The problem is that the pushrods are not at 90º as the cylinders are , but maybe at 100º or so. The holes in the manifold are drilled at 90º angle and paralell to the intake plane surface, and even with a generous hole you get little clearance at the top and the bottom of the hole oposite sides.
I tried a new set of pushrods which I ordered specially for an FE engine , and got 3/16" diameter rods. The old ones I am still using have a 11/32" shaft. If I have problems with 11/32" pushrods, how are guys with 3/16" rods getting along?
The new repair is going to cost a little more, and that will buy a new manifold. So I ordered a new FE Performer RPM , and will do the port matching and hope that I will not have to work on the pushrod holes also.
And my question is: is this happening because of my Dove billet rocker setup or is this problem common to all Fe engines . Is EVERYBODY sure that their pushrods are not touching the holes in the intake manifold and bending on operation? Go take the covers off and check! I broke 3 pushrods in 3 outings until I found out!