The background:
The history of the heads is soft of a mystery. We believed they were stock heads that had a valve job, with no machining....the surface was just cleaned up. Then I had those heads "street ported" by Mustang Specialties, where they ported them and took 30 thousands off the surface.
The lower intake is an Edelbrock performer, used but in very clean condition. It only had a few thousand miles on it.
I know, used parts cause problems.
The problem is the intake will not line up with the heads. The heads are on and torqued down, when we put the lower intake on, the bolt holes would not line up perfectly. None of the bolts would thread on, so we looked at the intake and noticed that each side of the intake needed to come closer to the head. Obviously that is impossible, so we figured the heads had been machined down more than we originally thought. So we widened the holes in the intake a little so the bolts would bolt onto the head. The intake would also not just sit on the heads and block. You should normally be able to just lay the lower intake on the long block straight, even with the valve covers on. But with this one we needed to remove the valve covers and still we had to lower the intake down one side at a time. So we removed a very small amount of the side edges of the intake so it would lay straight on the longblock.
Once we got the intake to bolt on we noticed two things wrong. The flat part of the block, where it meets the flat part of the intake on either end, had too much of a gap. With a thick silicone bead and the intake bolted down, it would not push out any silicone. The other thing was the intake runners would not line up perfectly. You could look down the runner and see a "drop off" into the chamber in the head...where they should line up perfectly.
We are thinking that the heads have been machined down further than we originally thought, because 30 thousands shouldn't cause an issue like this, right? So I am taking the intake down to a machine shop tomorrow to see if they can machine the intake to fit with machined heads. The problem is we don't know exactly how off the heads are. Without removing the heads again and matching them up to uncut stock heads.
Then after we solve this issue, I don't know what kind of a problem I will run into with my 1.7, bolt-down, rockers. We think those might need to be shimmed because if the heads are that machined, and the rockers are just bolted down, it might be causing the valve to stay open a little bit.
I just wanted to run this by everyone and get some other thoughts and opinions. I know I should have started off with NEW stuff, but I figured the intake was used but it's not like it can be "bad"...and we were VERY sure that the heads had never been machined any more than a light resurfacing. And Mustang Specialties is a VERY reputable machine shop who ports heads all the time with no problems.
The history of the heads is soft of a mystery. We believed they were stock heads that had a valve job, with no machining....the surface was just cleaned up. Then I had those heads "street ported" by Mustang Specialties, where they ported them and took 30 thousands off the surface.
The lower intake is an Edelbrock performer, used but in very clean condition. It only had a few thousand miles on it.
I know, used parts cause problems.
The problem is the intake will not line up with the heads. The heads are on and torqued down, when we put the lower intake on, the bolt holes would not line up perfectly. None of the bolts would thread on, so we looked at the intake and noticed that each side of the intake needed to come closer to the head. Obviously that is impossible, so we figured the heads had been machined down more than we originally thought. So we widened the holes in the intake a little so the bolts would bolt onto the head. The intake would also not just sit on the heads and block. You should normally be able to just lay the lower intake on the long block straight, even with the valve covers on. But with this one we needed to remove the valve covers and still we had to lower the intake down one side at a time. So we removed a very small amount of the side edges of the intake so it would lay straight on the longblock.
Once we got the intake to bolt on we noticed two things wrong. The flat part of the block, where it meets the flat part of the intake on either end, had too much of a gap. With a thick silicone bead and the intake bolted down, it would not push out any silicone. The other thing was the intake runners would not line up perfectly. You could look down the runner and see a "drop off" into the chamber in the head...where they should line up perfectly.
We are thinking that the heads have been machined down further than we originally thought, because 30 thousands shouldn't cause an issue like this, right? So I am taking the intake down to a machine shop tomorrow to see if they can machine the intake to fit with machined heads. The problem is we don't know exactly how off the heads are. Without removing the heads again and matching them up to uncut stock heads.
Then after we solve this issue, I don't know what kind of a problem I will run into with my 1.7, bolt-down, rockers. We think those might need to be shimmed because if the heads are that machined, and the rockers are just bolted down, it might be causing the valve to stay open a little bit.
I just wanted to run this by everyone and get some other thoughts and opinions. I know I should have started off with NEW stuff, but I figured the intake was used but it's not like it can be "bad"...and we were VERY sure that the heads had never been machined any more than a light resurfacing. And Mustang Specialties is a VERY reputable machine shop who ports heads all the time with no problems.