[HIVOLTJ]

Hey fellas, long time without posting, been out of Mustangs and Lightnings for a bit. I'm building a NON-HO roller short block with dished no valve relief pistons for my '48 f1 project.

I have PROMAXX 180cc heads with 2.02 intake valves and want to run a comp XE264 cam. I will be checking PTV clearance but I wonder if any of the cheaper pistons like speed pro have enough radial clearance for a 2.02 intake? I do not wish to grind on new pistons.

Pic for attention

 

[Quik5oh]

Great question. Subscribing.

 

[HIVOLTJ]

Sealed power answered me on Summit about their H273CP and said the valve reliefs are for 1.98" intake valves (possibly 1.94?)

It's odd I've been on here a long time. Flycutting pistons for 2.02 intakes is discussed often and also the superior clearance of twisted wedge heads. Never have I heard mentioned cheap shelf pistons with proper reliefs. Why would companies make 2.02 valve inline heads if there are no pistons?

 

[Mark O'Neal]

Because that's not their job. Their job is to move air....my job is to make pistons that work.

This will fix it In-Head Piston Cutters

The problem with you younger guys is that you think that whatever you want is what companies should make. No aftermarket piston company cares about "cheap." We care about delivering a quality product for as specific an application as possible.

Also... the last thing you need in a grocery getter is a 2.020 valve. There is no flow improvement below about 6,000 rpm. It won't hurt anything either, but there you are. You seem to be buying price, not application...and that's fine, but you have to choose your compromises.

You can also, budget permitting, run a set of Weisco PTS Series for about $550.00 including rings. Mahle might have something that "cheap" as well. Icon might also be "cheap" but I'm not happy with their consistency. All of the aftermarket performance piston companies use at least a 2.150 intake cutter. Speed Pro is not an aftermarket performance piston.

 

[Mark O'Neal]

Incidentally....cool truck.

I had one when I was a kid, but I kept the flattie in it. No horsepower, but smoother than silk.

 

[HIVOLTJ]

Mark ironically I bought these heads in part because of your recommendation on here you fargin sneaky bastage.

I'm not about always cheapest its about what makes sense for the budget and build.

If I'm gonna be cutting pistons I may as well keep the ****ty dished pistons and cut those. The .5-1 point gain in compression won't gain enough power to justify the new pistons alone.

This one is getting a flathead to start with, the 5.0 will be built on the side and go in later.

 

[Mark O'Neal]

Mark ironically I bought these heads in part because of your recommendation on here you fargin sneaky bastage.

I'm not about always cheapest its about what makes sense for the budget and build.

If I'm gonna be cutting pistons I may as well keep the ****ty dished pistons and cut those. The .5-1 point gain in compression won't gain enough power to justify the new pistons alone.

This one is getting a flathead to start with, the 5.0 will be built on the side and go in later.

They're a good head. You just have to buy parts that work with them. If the ****ty dished pistons will work, I agree. But spend the dough on the Lindy tool and do a bit of work, they'll fit and you'll be prepared for next time. Use a 2.150 cutter as a minimum.

If you figure out how to get the generator belt tension right with just two hands....please share.

 

[Quik5oh]

If I'm gonna be cutting pistons I may as well keep the ****ty dished pistons and cut those. The .5-1 point gain in compression won't gain enough power to justify the new pistons alone.

That's what I would do, just cut the pistons that are already in the block. Funny, I keep a H273CP .030 on my desk as a paper weight and I just mic'd the pockets... sure enough, they are not gonna fit a 2.02.

 

[Quik5oh]

The problem with you younger guys is that you think that whatever you want is what companies should make. No aftermarket piston company cares about "cheap." We care about delivering a quality product for as specific an application as possible.

Totally agree... I guess I would consider myself a younger guy even though I'm past my 30s... I totally agree with your statement and it's one that those of us that want to learn should simply say, yup, thanks for the guidance and for making a valid point.

Also... the last thing you need in a grocery getter is a 2.020 valve. There is no flow improvement below about 6,000 rpm. It won't hurt anything either, but there you are. You seem to be buying price, not application...and that's fine, but you have to choose your compromises.

Another great point... makes me feel better about buying 1.90 - 1.94 intake valve heads for my street cars. I know people running 2.05 intake valve heads on 400fwhp motors and it seems pointless to me and likely is.