Pushrod clearance to head??? 3/8" will not fit TFS heads
03-03-2010, 08:40 PM
#1
Pushrod clearance to head??? 3/8" will not fit TFS heads What is the recommended pushrod clearance to the head...My 3/8" pushrods do not clear my head holes...I am pretty pissed right now considering i called TEA and made sure that 3/8" would clear the 215 TFS...i figured they would know best since they made the heads 
...
So is there a rule of thumb for clearance on pushrods to the wall of the heads...thanks
Chris
...So is there a rule of thumb for clearance on pushrods to the wall of the heads...thanks
Chris
03-03-2010, 10:26 PM
#3
Chrs sorry to jack but are you running your 230/230 cam? If so what did you mill too? I was told I could safely go to 60.5cc but I am kinda nervous about cutting that far. Especially since my cam was not degreed so I don't really know my actual valve events....
03-03-2010, 11:04 PM
#4
if I were you I would not cut that much...I would mock up the heads before being milled and find the ptvc and then decide what you want to take off...I only had .086 on the intake with stock 66cc 241s and stock mls gasket...I would not take anyones word on that...look at me I am proof of that with these pushrods...
03-03-2010, 11:08 PM
#5
don't know what I want to do now to fix this...polish the pushrods down a hair on the lathe with some light grit sandpaper...pull the motor again flip it upside down on the engine stand and open the holes up...just get thinner pushrods(which would suck considering these were custom length trends $200+)...or run the biach the way it is...
03-04-2010, 04:34 AM
#6
Don't polish the pushrods, you could introduce a focal point for fatigue failure. I think I would consider selling and moving to a double taper (I have information on these if you need it). If they are contacting they will tend to move towards the intake side while opening and it will put a lot of side load into the pushrod cup of the rocker, something it is not designed for and you could end up with bigger issues.
What length are the pushrods?
What length are the pushrods?
03-04-2010, 07:13 AM
#7
Don't polish the pushrods, you could introduce a focal point for fatigue failure. I think I would consider selling and moving to a double taper (I have information on these if you need it). If they are contacting they will tend to move towards the intake side while opening and it will put a lot of side load into the pushrod cup of the rocker, something it is not designed for and you could end up with bigger issues.
What length are the pushrods?
What length are the pushrods?
also I don't see takin off 5 thousands affecting the overall structure of the pushrod it is only hitting about 2" from the tip...we will see I can get some 5/16" for $94...just paid 240 for these being a custom length...don't know who would want these if I tried to sell them...I would need someone to be able to clear a 3/8" rod and also need this exact length...doesn't seem like a big market for it...maybe trend will take them back at half price and just keep them in stock...
I don't know we will see...I need to think about it more
Chris
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03-04-2010, 08:12 AM
#8
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what the hell brand did you buy for 240 edit:see you said trend...manton did mine 3 pc 3/8 for like 140 and he did 2 different lengths for me 8 for the intake and 8 for the exhaust so preload would be the same (they were around 7.565")...did you buy your TFS heads new? what rockers? what lifters the NEW TFS heads were machined for 3/8....i squeezed in 3/8" on mine with the older TFS heads prior to 3/8 pushrod hole machining...like shawn said...i put in the 3/8 and there was no contact through the entire valve motion. Im running YT rockers and comp 850-16s...seems like such a short pushrod for those heads...sounds like stock rockers, milled heads and a tight gasket....did you do that 235 243 LSL grind?
03-04-2010, 08:45 AM
#9
what the hell brand did you buy for 240 edit:see you said trend...manton did mine 3 pc 3/8 for like 140 and he did 2 different lengths for me 8 for the intake and 8 for the exhaust so preload would be the same (they were around 7.565")...did you buy your TFS heads new? what rockers? what lifters the NEW TFS heads were machined for 3/8....i squeezed in 3/8" on mine with the older TFS heads prior to 3/8 pushrod hole machining...like shawn said...i put in the 3/8 and there was no contact through the entire valve motion. Im running YT rockers and comp 850-16s...seems like such a short pushrod for those heads...sounds like stock rockers, milled heads and a tight gasket....did you do that 235 243 LSL grind?
I am still debating on what I want to do...decisions...
and as for the preload it is almost dead on...intake is 1/2 turn and exhaust is just a hair under 3/4 turn...
.040 gasket...and milled to 57.5cc...
03-04-2010, 09:50 AM
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manton doesnt charge extra for custom length...you tell him the length and he makes them...i gave him my specs and he had them out the same afternoon...what lifters are you running? and for the cam?
03-04-2010, 10:05 AM
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Chris,
I think there is something different with your particular heads. Those pushrod lengths seem short considering your setup. I've only ever run 3/8" Mantons with those heads and never had a clearance issue. I don't think I've seen anyone at much less than 7.500" with those heads and rockers. It looks like your heads have been milled much more than you thought. This could change the pushrod geometry enough to cause your issue. I might be able to work something out with your custom pushrods. I use 7.425" all the time in other apps. I could get you some 11/32" .120" wall Mantons instead.
Shane
I think there is something different with your particular heads. Those pushrod lengths seem short considering your setup. I've only ever run 3/8" Mantons with those heads and never had a clearance issue. I don't think I've seen anyone at much less than 7.500" with those heads and rockers. It looks like your heads have been milled much more than you thought. This could change the pushrod geometry enough to cause your issue. I might be able to work something out with your custom pushrods. I use 7.425" all the time in other apps. I could get you some 11/32" .120" wall Mantons instead.
Shane
03-04-2010, 10:10 AM
#12
and yes 239/243 .624/.624 on 111+4 but when degreed it was on a 109.5lsa sucks but I decided to just run it and install it 2 degrees retarded...the valve events are closer now to what they should be...
Last edited by chrs1313; 03-04-2010 at 07:56 PM.
03-04-2010, 05:51 PM
#16
Chris,
I think there is something different with your particular heads. Those pushrod lengths seem short considering your setup. I've only ever run 3/8" Mantons with those heads and never had a clearance issue. I don't think I've seen anyone at much less than 7.500" with those heads and rockers. It looks like your heads have been milled much more than you thought. This could change the pushrod geometry enough to cause your issue. I might be able to work something out with your custom pushrods. I use 7.425" all the time in other apps. I could get you some 11/32" .120" wall Mantons instead.
Shane
I think there is something different with your particular heads. Those pushrod lengths seem short considering your setup. I've only ever run 3/8" Mantons with those heads and never had a clearance issue. I don't think I've seen anyone at much less than 7.500" with those heads and rockers. It looks like your heads have been milled much more than you thought. This could change the pushrod geometry enough to cause your issue. I might be able to work something out with your custom pushrods. I use 7.425" all the time in other apps. I could get you some 11/32" .120" wall Mantons instead.
Shane
right now the intake is just a hair under 3/4 turn and the exhaust is a hair over 1/2 turn...from zero lash...i have checked them about 5 times to make sure, on different holes too...
