Page 1 of 1

head fixture plates

Posted: Wed Apr 03, 2019 11:53 pm
by cgarb
What are most people using for head fixture plates? I hear about slider plates and I see aluminum fixtures for sale...which are quite pricey I may ad...fixtures made of lexan. My question is what is a good simple design fixture to fixture common sbc/bbc and some fords. I am a machinist by trade and fabricating something is my wheelhouse. I'm just not sure what is needed exactly. A flat plate with a hole and dowels seem adequate to me. Are the slider plates for set up and testing speed? What seals the head to the plate? Sorry if I'm asking complete newb questions, but I'm just trying to get an idea of what I need to get started.

Re: head fixture plates

Posted: Fri Apr 05, 2019 10:21 pm
by Brucepts
This might get you headed in a direction . . .

Re: head fixture plates

Posted: Mon Apr 08, 2019 5:42 am
by RACEPUMPER
I just use a head gasket to seal the head to the adapter but you could also machine and O - ring it.
Bruce's design is a great base and will give you a good start.
When you get up to tapping threads allow for the head to be on in different positions obviously.
Although I've never used one, a sliding head adapter would have to be a big time saver.

Jim

Re: head fixture plates

Posted: Mon Apr 08, 2019 5:20 pm
by cgarb
On the attached print would you make sleeves for the 5" of tube to adapt to different bore sizes? I also saw some similar to that that had something like a 4.030 end and a 4.155 end for small blocks and 4.250 and 4.500 for big blocks. Would it matter if there is a step in the bore?

Re: head fixture plates

Posted: Tue Apr 09, 2019 7:22 pm
by 1960FL
For the most accurate results your bore should be same as motor and head location must be as on the block as the valve to cylinder wall location can have a measured affect on the numbers.

Yes many use sleeves to reduce the sizes but if you don't have the equipment to bore and fit these try to get a sleeve that is within .100 of your running bore.

Rick