So I just picked up our set of 215s (Thanks Shane!) from the shop yesterday after a complete rebuild and for the first time we compared them to the 236 peanuts that were on there before. HOLY COW! :eek: :eek: :eek: What a difference in the port size!

The 215's were already ported and polished when we got them and also had the 2.19 valves in them too.

So now I'm curious... spec wise, what kind of performace difference in terms of raw HP percentage or torgue, or... can one expect from porting and polishing 215 heads? From putting the 2.19 valves in? Both?

They're going into a 454 + .030 with a Comp 270H cam, flat pistons, an AirGap manifold, 3310-2 750 Holley and 2-1/2" headers. We're not talking about the rear end right now, but the TH400 will stay and we'll be adding a 2400-2800 converter.

I'm thinking this motor will REALLY wake up compared to the original 236 heads, a Q-jet and a stock intake... !

Any guesses or predicted specs?

awwww man!
Nobody has input on the gains or a comparison?

You should be over 500 for hp and torque. Those heads will support 600 hp or more.

i hope you see that much
shane

Who knows what the quality of the port work is on those heads. Thats why its hard to call, but Ill say that even with proven, great cylinder heads, it would be hard to stretch anything much over 420 horses out of a 270 magnum...and thats even generous. Still though, the heads you have now have much more potential than the 236 you got rid of.....lets just hope the port work was quality.

It should have strong pull just above idle and Id imagine it will start to crap out in the 5000rpm range. You can probably rev a little further, but not much cause it wouldnt be worth it with that camshaft.

One possible problem I see is the compression. Those heads are 101cc I beleive. With a flat top piston, and depending on the size of the valve releifs and quench distance, you can easily be well under 9:1 compression. That will be a tad sloppier than it coulda been with more compression(All depending on the valve releif size and quench...it may not be a huge issue). Still though, even with small valve releifs and .040 quench, you wont be very much over 9:1 compression. And of course going to a much larger port head with much larger valves is going to show a low end torque loss by itself. Those peanuts might not make much power, but they can make torque, so you will probably see a noticeable difference in off idle torque. IF the compression numbers dont work out in your favor, and coupled with the bigger port, big valve heads, the motor can potentially be pretty soggy at low revs. This is all speculation so far though.

What is the deck height of your block and the gasket thickness? Do you know anything more about the pistons other than that they are flat tops.....like valve releif size? That would help.

Shane - I do too... I THINK!

Greg - Being as this is a weekend crusier and not a strip racer, I'm not too worried about getting soggy above 5K. A few hits on the gas and a little tire heating is going to be the norm. We'll make it to the strip a few times, but it's not the intent. As far as the heads, I've seen two quotes on them - one at 101 and one at 96. Haven't checked the deck height and the gaskets aren't going to be anything special. The pistons are generic SpeedPro Flat Tops. Dunno about the relief size.

400+ HP is more than enough. Well, okay, it's enough for the first mod of the car anyway. We'll be doing round two mods over time once the car is done this summer and a bigger cam and small dome pistons may be in the works. Right now, I just want to hear it run and smell tire smoke! smile.gif

Most books say about 101cc for them, but some that have measured them say they come in at around 105cc.
If you put larger valves in them and then unschrouded the intake valve, they can be much larger than the 105cc. The only way to know is to measure them.
Bill

I have a virgin set of 063's heads (same as 215's) with small valves and not milled sitting on my garage floor that cc'ed at 107-108.

I take most of the chamber size values printed in books with a grain of salt.

Tom aka "mc71454" used to run a mild .060 over 454 with flattops,stock,unported closed chamber ovals 2.06/1.72 valves and the Comp 270H ran a best of 12.65 at 104.9 MPH using a B&M 2400 convertor and 3.55 gears.
This is with alot of tuning and hooking vey good.
That cam is 224 @ .050 and gound on a 110 LSA
With the big valves and increased compression (probably about 9.0 to 1) you're probably in the 425-440 HP range

Chris - that's exactly what the cam is - and I'm thinking a little longer rocker in the future may help it a tad too. Just don't know if the 215s will support that - the flat tops don't have much of a valve relief AT ALL!

The head gasket is just a vanilla fel-pro blue one that came in the master kit. Like I said before, we're not real worried about getting every last bit of compression there. I'm guessing the port n' polish and the bigger valves will be a help, but the modest cam will definitely have limits on the performance. Once the car is done and we've driven it for awhile, we'll go back and see what other damage we can do... Gotta track down a 3.55 posi to replace the one legged 2.56 broomstick for sure!

You'll be able to get into the mid/low 13's with 2.56's IMHO and experience..as long as you have a mild stall and a pair of drag radials.If I did it,so can you smile.gif

2400-2800 is what we're planning on.

Dunno about drag radials though - probably just some good street tires. Like I said, not concentrating on a drag strip car...

You should pick up about .2 to .3 points more CR. if you go with a pair of Mr. Gasket .020" thick, steel shim headgaskets.

Imho, at this CR. level, every little bit helps is all..

pdq67