heads for flat top pistons

Topic: heads for flat top pistons (Read 5085 times) previous topic - next topic

heads for flat top pistons

July 08, 2014, 01:13:18 PM

What aluminum/iron heads (better than E7s) work with these flat top pistons? I read that GT40s won't work or that you have to carve reliefs into the pistons or change them out. I've also read that porting E7s is waste of money. Do any of the aftermarket heads work right out of the box? My goal is 300 HPRW. On Ebay, the seller of those pro comp heads says they will work but if he's just trying to make a sale and I'm stuck with $600 door stops, I will not be happy.

thanks.

heads for flat top pistons

Reply #1 – July 08, 2014, 05:22:38 PM

keep in mind, there is a lot more to factor in when worrying about if your valves will hit. cam and rocker ratio play an important part in this too. and as far as pro comps go, just pass. i bought some years ago and never installed them once i read all the horror stories. there's a lot of problems with them, i believe the valve guides falling out were their biggest problem.

heads for flat top pistons

Reply #2 – July 08, 2014, 06:14:19 PM

Darn, thought I could get a decent set of aluminum heads for $600. I have read some bad things too but nothing specific. Maybe buy them without valves and springs and have those put in by a pro shop? I have an standard HO cam to replace my SO cam. What is a safe combination? HO cam + 1.7 rockers + ? aluminum heads

or E303 cam + 1.6 rockers + ? aluminum heads?

heads for flat top pistons

Reply #3 – July 08, 2014, 07:04:21 PM

Trickflow heads.

heads for flat top pistons

Reply #4 – July 08, 2014, 07:13:18 PM

Quote from: grutinator;435640

keep in mind, there is a lot more to factor in when worrying about if your valves will hit.

Yeah, like will the spark plug boss on my GT40P headshiznit the piston crowns if I have domes? (yes, ask me how I know)

heads for flat top pistons

Reply #5 – July 08, 2014, 09:23:37 PM

Quote from: Haystack;435643

Trickflow heads.

This is what Ive heard too.

heads for flat top pistons

Reply #6 – July 08, 2014, 09:38:47 PM

Any high port head basically relocates the valves/angles.

back in the sleazy board days, everyone ran trickflow high ports with any cam they wanted without kissing a valve.

heads for flat top pistons

Reply #7 – July 08, 2014, 10:31:04 PM

Valve reliefs are a simple thing to achieve. Dont let that be the determining factor. Basically the very poor flow of a ford head is its issues. So if you have to cut in EYEBROWS and you will have to to achieve your goal. Do it and then you wont have to worry. Relocating ford valves require piston machining or better known as eyebrows cut in to the pistons. CPR recommends it with all there performance relocated valve heads. If you raise the exhaust port and that is necessary to get the flow numbers up you might need custom headers in some applications.You need lots of lift to overcome the poor flow from a small block head. (basically simply put other factors are involved) So adding eyebrows are a definite. Like i said it is easy to do and the difference in HP is beyond the issue of cutting them. You will also need squeeze to get the numbers you are looking for Good luck on your build Have a great evening guys.

heads for flat top pistons

Reply #8 – July 09, 2014, 12:17:01 AM

youve gotta watchout with the trick flow heads though. I think the valves are actually relocated slightly. so any valve reliefs in the top of the piston may "mis-align" and cause some unintended contact.

Ive also head good things about AFR (Air flow research) heads.

I think most aluminum heads new go for $1200 and up....sorry

heads for flat top pistons

Reply #9 – July 09, 2014, 02:49:22 AM

Trick flow heads also don't use stock valve releifs and clear fine with a 2.02 intake valve.

they will clear fine, especially if you stay with a stock h.o. cam, which i would personally do.

btw, I'm referancing the twisted wedge 50 state legal 170cc heads.

heads for flat top pistons

Reply #10 – July 09, 2014, 06:39:04 AM

The guy wants to make 300 WHP he aint doing that with an HO CAM !!!!!!! And he will need all the flow he can get so that is the issue with the build. Making 300 WHP on the small FORD is not cheap or easy to an extent. I just finished a 347 and it dynowed @ 329 WHP on a MUSTANG DYNO and the build was NA. Not great numbers by any means but good for the setup at hand. You need valve reliefs no matter how you look at it if 300 WHP is your goal. You can take that to the BANK!! When cutting reliefs you have to do it with the head you plan to run. A relocated valve is not an issue at all. Have a good day guys.

Never assume a cam will clear a piston no matter how many times someone says they do. They have to be checked.

heads for flat top pistons

Reply #11 – July 09, 2014, 07:21:08 AM

Heads, cam and custom machining of stock flat tops is a lot of money to spend to put 300 horse on the road. If you want to make power, you're going to have to start with pistons that have reliefs, don't bother trying to machine the ones you have, you'll spend less money and end up with better parts. Somebody here will probably sell you some HO stockers (forged with valve reliefs) if you ask around. I've got a spare set, but I don't know if I'm ready to part with them. For heads, GT40s will probably get you there on the cheap, but a nice set of edelbrocks or afrs will get you a lot further, and you WILL need a cam. HO won't do it, and neither will 19# injectors (absolutely forget 14#s), so plan on .480 lift or better and at least 24# injectors. You'll need a GT40 intake at minimum, and 60+mm openings. Hope that's helpful.

heads for flat top pistons

Reply #12 – July 09, 2014, 07:39:14 AM

I agree start with pistons with valve reliefs and start from there. Depending on your sweep compression and HP numbers you plan on making. But remember small ford heads do not flow very well and that is why making real HP numbers is so difficult. But cutting reliefs are no big deal. I do it all the time. Have a good day. I would think a cam with more lift is necessary as the small ford head needs it to flow good numbers. looking at my charts would necessitate a cam in the 550 range to get the numbers over 325-360 WHP. Just saying.

heads for flat top pistons

Reply #13 – July 09, 2014, 09:35:42 AM

http://ls1tech.com/forums/generation-iii-internal-engine/1155880-how-flycut-pistons-ls1-free-almost.html

I did this with the red car. Stock flat-tops, wanted to put GT40s on it. (non-p, just for reference) Not incredibly accurate, I did not ensure TDC to a high degree of accuracy with a dial indicator, but I used a valve bigger than what I was applying with the head, so I built in plenty of safety margin. Not sure if I lost excessive compression, but the reliefs didn't look that big to me. In fact I didn't even make complete half-circle eyebrows for any of them. Using your cam lift and rocker ratio, find out what the actual valve lift will be, use a Sharpie and mark this on the valve stem, go from there. You can easily build in whatever extra safety margin you want. I did just this, and I've spun the motor right up to its limiter plenty of times. (Stock HO cam, by the way) Runs great, very smooth, no problems.

But I was duly impressed by this. CAREFUL, that sandpaper marches right through the aluminum quicker than you'd think!!!!!!

heads for flat top pistons

Reply #14 – July 09, 2014, 09:45:15 AM

Thanks guys. Haystacks says I can get away with the Trickflow TW 170 with the HO cam. Sounds like I'm not going to get 300 HP. What can I expect? 250? 275? If I go the route of changing out the pistons, we're now talking about removing the engine, getting the cylinders bored, new rings etc... right? Big $$$$.