Engine Rebuilt Suggestion & Question...

97GTSTANG · Aug 2, 2011

My 97GT has a cracked head, so i wanted to get a stage 3 01+ port and polish heads and comp cams 262 installed on my stock 97 block. Will i have to get the pistons notched or will the 262 comp cams be ok? Will i have to do anything else to the car to gain any additional horsepower? Will the stock fuel injectors work fine? how about the MAF? Will i need to get a tune?

With the stage 3 port and polish heads and the cams, what sort of gains will i get? what will the compression be at? I do not intend to have nitrous or supercharger. Just want the most i can get out of a NA car.

Thank You

trombonedemon · Aug 2, 2011

This seems kinda "iffy" with higher compression on the NPI engine with higher lift cams with the PI heads. From reading W.M. Burns's post, you might run into some piston to valve contact issues.

1987stangman · Aug 2, 2011

If it was me. I would pull that motor out and deal with the head and then sell it off as a working piece and then use that money to help pay for a low mile P.I motor then do what you want with it.

97GTSTANG · Aug 3, 2011

any info?

N8Dogg98 · Aug 3, 2011

trombonedemon said:
This seems kinda "iffy" with higher compression on the NPI engine with higher lift cams with the PI heads. From reading W.M. Burns's post, you might run into some piston to valve contact issues.

A properly degree'd 262 cam intended for PI heads will not cause PTV contact, even with flat pistons.

OP, if it were my car, I'd pull the engine and build a lightweight aluminum engine (explorer, Mark VIII, and 96-01 Cobra's all had aluminum blocks) with some flat pistons. Have valve reliefs cut into those pistons and install your stage 3 heads with a stage 3+ cam having an aggressive intake centerline. A combo like that would be close to 11:1 compression and would offer great torque and lots of high RPM HP potential.

Honestly if you're spending the money on stage 3 ported heads and only installing a mild 262 cam it seems like somewhat of a waste.

97GTSTANG · Aug 3, 2011

Thanks N8 Budget is a bit of a problem right now. Stage 2 port and polish heads and comp camps 262 will clear the stock 97GT block? Will i have to get flat valves? (thinner ones) or pistons notched?or will the pi valves work perfectly without piston to valve problems?

I am contacting Module Mustang Racing for the stage 2 port and polish

bullitt 736 · Aug 3, 2011

Contact Nick McKinney by email at Modular Head Shop

You can get his email address on the site.

Check out his heads, cams and tech articles.

N8Dogg98 · Aug 4, 2011

97GTSTANG said:
Thanks N8 Budget is a bit of a problem right now. Stage 2 port and polish heads and comp camps 262 will clear the stock 97GT block? Will i have to get flat valves? (thinner ones) or pistons notched?or will the pi valves work perfectly without piston to valve problems?

I am contacting Module Mustang Racing for the stage 2 port and polish

The 262 PI cam doesn't have an aggressive enough intake centerline to cause PTV issues.

FWIW, PTV clearance in the 4.6 really has nothing to do with total valve lift, rather it has to do with the point in which the valve begins to open and how quickly it opens fully.

Just make sure you have the cams properly degree'd no matter what package you decide to go with. I don't just mean lining up the chains in the appropriate place, I actually mean measuring and setting the cam up such that it opens the valve at the precise moment it was designed to.

I don't have the tools to do this and have never done it myself, instead I paid an extra $150 to Nick McKinney at MHS when I bought my cams and he degree'd the cams for me and sent me adjustable crank gears so I could properly time my cams.

Here's an article if you're interested in doing it yourself.

ModularHeadShop Articles on Cam degree

97GTSTANG · Aug 4, 2011

whats the difference between stock springs and upgraded springs, will the upgraded springs help with the piston to valve clearance? will the thinner valves also help? i really dont want piston to valve contact on stock npi block. Will the mechanic just drop the heads in and bolt everything down or does he have to do anything different to ensure that there are no piston to valve issues?

N8Dogg98 · Aug 4, 2011

Like I said, you won't experience PTV with the 262 comp cam designed for PI heads. I don't know how many more ways I can say this. Also, upgraded valve springs have nothing to do with preventing PTV, rather they have to do with ensuring there is enough seat pressure applied to the rocker so that it precisely follows the camshaft. W/o upgraded springs some of the more aggressive cams will cause the valves to float.

As far as "thinner valves" I assume you're speaking of SS valves. The PI head intake valves have a tulip like shape, while oversized SS valves have a flat bottom surface, so yes you do in fact gain a very small amount of additional clearance. However, if you're running the 262 cam this really doesn't matter because the 262 PI cams will not cause PTV when properly degree'd.

LastCallRacing · Aug 5, 2011

As said, the 262's are a great cam choice really. No problems with PTV and if used with PI heads and PI valve springs you won't have problems with coil bind either.

You'll get a compression bump with the PI heads, and that will translate into some extra power as well.

Let us know if we can be of any assistance for your build.

Engine Rebuilt Suggestion & Question...

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