13/4 intake
 

Has anyone used 13/4 intake valves and fly cut the heads'

Re: 13/4 intake
 

Has all been done in years past by many.

Re: 13/4 intake
 

What does 13/4 mean? I am not familiar with that term. Thanks. jim

Re: 13/4 intake
 

I believe he is talking about 1 3/4" or 1.75" intake and exhaust valves.

Re: 13/4 intake
 

Re: 13/4 intake
 

Stupid me I thought it was a metric question :eek:

Re: 13/4 intake
 

Haha

Re: 13/4 intake
 

I use the 1.72 chevy buils in the street engunes instead of a cam. Gota shorten the valve some, but works just fine, no head mods needed. adds alittle more air, but doesn't kill low end torque,
Gramps

Re: 13/4 intake
 

I use 1.72" intakes and put larger hardened valve seats in the block. You have to have the special hard seat cutter to put the larger seats in.

The seat I use is an SBI - SB1750-8.

If you take the hard seats out, you can put a 1 3/4" valve and put the seat right into the cast iron of the block.

The valves I use are high-quality Manley pieces for early SBCs. they have a nice profile and are standard SBC length (which is a bonus for a big cam with a small base circle). You'll have to make special retainers and usually shim the Isky 185-G springs to get whatever lbs on the seat you need.

1.72” Manley Intake Valves: 12342-8

Re: 13/4 intake
 

Here are some links to vids related to cutting and installing new seats. You'll see my good friend Jeff Fowler in the vids - this was the last engine he worked on before he closed his business in Columbus, OH. His operation was the best machine shop I've ever worked with. We did some amazing things with top-alcohol custom blower designs. I'll post a picture below of the last blower design I worked with him on (there is one more, but I can't show it! LOL):

https://www.youtube.com/shorts/ZdR1zZLZaTw

https://www.youtube.com/shorts/5Z-EheS73zM

https://www.youtube.com/shorts/aCrNzCg4W1A

Re: 13/4 intake
 

Here it the last commercially available Fowler 14-71 blower (I know - this is totally off topic!). This is a rendering I did with SolidWorks:

Attachment 543083

Re: 13/4 intake
 

Re: 13/4 intake
 

Zat u in the video Dale? Whatcha smokin? LOL

Re: 13/4 intake
 

Naw, that is Jeff Fowler . . . he is smoking a bitty cigar, not a blunt! LOL

Re: 13/4 intake
 

I always wonder what other members look like. Sometimes someone else slips in a picture of members, even the banned fellas, like CharlieNY. I liked the picture of the "counselor" sound asleep in his recliner. When I occasionally get to the Wisconsin swap meets I know I walk past Barners that I have communicated with here. It would be nice if we could order Fordbarn t-shirts with our Fordbarn ID on them. Maybe even jackets. I would be proud to wear one. Might even have my wife let me wear it in my casket! LOL As dedicated as our many many fellow members are I would think that it would be a worthwhile endeavor for some younger member. I know Mickael Driskell probably has his hands full but we surely have other members up to the task. Maybe Ryan???

Re: 13/4 intake
 

"I use the 1.72 Chevy builds in the street engines instead of a cam.... adds a little more air, but doesn't kill low end torque""


I agree

Re: 13/4 intake
 

we ground the seats right in the block

Re: 13/4 intake
 

This is usually how it is done with full-on race engines - pull the hard seats out and grind the seats right in the cast iron. There is no issue with this and it gets rid of the challenge of putting much larger hard seats in the block.

Also, pay a lot of attention to the style of valve head on the 1.75" valves. If this is strictly a race engine, then think about well-shaped and thinner valve heads and I'd probably use a 30 degree intake seat instead of the usual 45 degree seat. I used to profile the valves on my lathe - really thinning the heads and to make a nicely curved/smooth transition from the stem into the top portion of the valve.

Re: 13/4 intake
 

I have an old Bonneville engine I have owned for over 25 years with the most amazing port job ever. It has 1.800 intake valves and 1.700 exhaust. 3.375 x 4.250. Had a Potvin Eliminator cam. I may have to dig it out and resurrect this gem. Unfortunately I don’t know whose car. Block has 4 sleeves so could tell some stories. Both valve seats ground into block.

Re: 13/4 intake
 

what is the CI of that motor?