Speed-pro pistons + TW heads + TFS II cam

[90mustangGT]

I have a 306 shortblock and TFS TW heads. The pistons are Speedpro forged with the 4 valve reliefs. I am looking at the TFS Stage II cam 224/232 .536/.563 on 1.6's. Will I have to worry about valve clearances with this setup.

Of course a custom grind cam would be better, but then again so would a 418 stroker with a dart block and a 110mm turbo, but funds are a little low.

 

[90mustangGT]

TTT...

If anyone knows, please give me some insight. I guess I'll just have to use the clay method on this one.

 

[ROBSLXTASY]

no

That will not clear..Sorry bud.. I have the TFS II cam with afr 165's with 1.90 valves and it barely clears the same pistons you have.. The stage 1 cam with 1.6's will give some respectable power and good times though..The 2.02 valves are the clincher..

 

[90mustangGT]

That will not clear..Sorry bud.. I have the TFS II cam with afr 165's with 1.90 valves and it barely clears the same pistons you have.. The stage 1 cam with 1.6's will give some respectable power and good times though..The 2.02 valves are the clincher..

That's what I am afraid of. Maby I will just have to give a custom grinder a call and or get the pistons flycut. I have heard different things, some say it will because the offset valve position of the TW valves, they are not inline like the AFR's.

 

[ROBSLXTASY]

yea

Yes the canted valves also screw with things but if the tfs's had a 1.90 intake valve it would probly clear.. Somebody sells a drill bit (basically looks like a forstner bit) that slide into the spot that each valve goes and you can flycut your own pistons without taking them out of the block..You would just have to remove each valve on one head and use maybe three bolts to hold the head down to the block each time you cut a piston.. And just mark a spot on the bit or use a bit clamp to mark how deep you need to go..Just an idea..

 

[Grn92LX]

It should clear as quite a few guys run that cam/head on stock bottom's and it fits. You have an aftermarket piston which should have deeper reliefs. Impossible to say for certain w/o checking.

Personally, cough up the extra $200 for a custom cam (+ valve springs of course which are NEEDED no matter what) and build the engine to make power.

You have a performer manifold right? Stick an RPM upper on it along with an aggressive cam from FTI and tell him you want mid 11's n/a and you should see like 330rwhp.

I know all about the budget thing as i'm building a 347 as we speak. But if an extra few hundred dollars make or break the project, you either need to stop or save up a bit more. Spend a little more now so your happier down the road. In my case, spending a "little more" now would have been about $1,000 so I didn't take my advice That why i'll be using unported TFS heads on my combo.

 

[90mustangGT]

Yes the canted valves also screw with things but if the tfs's had a 1.90 intake valve it would probly clear.. Somebody sells a drill bit (basically looks like a forstner bit) that slide into the spot that each valve goes and you can flycut your own pistons without taking them out of the block..You would just have to remove each valve on one head and use maybe three bolts to hold the head down to the block each time you cut a piston.. And just mark a spot on the bit or use a bit clamp to mark how deep you need to go..Just an idea..

I think I might do that. That is what happened to the heads I got, the guy ran a TFS stage I cam on stock pistons and they made contact with the valves, gernading his engine and causeing a lot of damage to the heads. The heads have all new valves in them and the damage was professional so they are good, but I don't want to repeat that problem.

 

[ROBSLXTASY]

It should clear as quite a few guys run that cam/head on stock bottom's and it fits. You have an aftermarket piston which should have deeper reliefs. Impossible to say for certain w/o checking.

Personally, cough up the extra $200 for a custom cam (+ valve springs of course which are NEEDED no matter what) and build the engine to make power.

You have a performer manifold right? Stick an RPM upper on it along with an aggressive cam from FTI and tell him you want mid 11's n/a and you should see like 330rwhp.

I know all about the budget thing as i'm building a 347 as we speak. But if an extra few hundred dollars make or break the project, you either need to stop or save up a bit more. Spend a little more now so your happier down the road. In my case, spending a "little more" now would have been about $1,000 so I didn't take my advice That why i'll be using unported TFS heads on my combo.

Theres no way anybody is running a stage II cam with completely stock bottom end (pistons included) with tfs heads..Even if they were somehow able to make it fit one time hitting the rev limitter could cause disaster without the proper "safe" clearance between piston/valve..

 

[Grn92LX]

Theres no way anybody is running a stage II cam with completely stock bottom end (pistons included) with tfs heads..Even if they were somehow able to make it fit one time hitting the rev limitter could cause disaster without the proper "safe" clearance between piston/valve..

Sorry Rob as your incorrect. It HAS been done quite a few times. Guy are doing it on 100% stock bottoms. Always check to be sure when running a cam like this on a stock bottom though.

 

[90mustangGT]

Theres no way anybody is running a stage II cam with completely stock bottom end (pistons included) with tfs heads..Even if they were somehow able to make it fit one time hitting the rev limitter could cause disaster without the proper "safe" clearance between piston/valve..

I hear that. That would suck. These are Speed-Pro flat tops witht the stock style 4 valve reliefs, which are larger and deeper than stock valve reliefs. I am really thinking of going with some TFS pistons, but money is an issue, but I don't want to take chances. I think I will end up calling/emailing around to see what I can do. Thanks for your input Rob.

 

[5spd GT]

Jason, Do you know how much more clearance the Speed-Pro pistons have over the stock pistons when looking at the reliefs? Any measurements? Are they deeper or wider or both? Any lighter than the stock piston?

Thanks

 

[90mustangGT]

Jason, Do you know how much more clearance the Speed-Pro pistons have over the stock pistons when looking at the reliefs? Any measurements? Are they deeper or wider or both? Any lighter than the stock piston?

Thanks

Good Quesions. I think it's time to get out a mic and do some measurements. I looked up TFS's site and it said 224 durration at .540 lift max with stock pistons. The reliefs look a lot deeper and wider but then again they are flat top instead of dish so the reliefs look deeper, I really don't know. I also e-mailed ed curtis at FTI to see what he thinks. I really plan on a custom cam from FTI sooner more than later. That is probally what I will do instead of the TFS cam. However I don't want any miss matched parts otherwise.

 

[Grn92LX]

My old FTI cam was 224/228 .547/.536 and it cleared fine on a stock bottom with TFS heads milled .020". Open/close events have a lot to do with it. I say get a cam from Ed (or any other good cam grinder) with matching springs and make soem power!!

I have my old FTI springs i'd sell ya cheap if my friend doesn't take them.

 

[90mustangGT]

Your right, maby it would be best to just get a custom grind cam to make it work. I'm on a budget, can't really pull $500 extra that easily. Maby compression will be a little low, but that's just an excuse to start a turbocharging project.