Ok I'm building a 306 with trickflow heads, trackheat intake, custom cam,75mm t/b, 80mm mass air, and a blower. Right now my internals are a new stock crank, reconditioned rods, and speed pro forged pistons. My compression is around 9:5:1 or a little lower maybe 9:3. I'll be running around 8-10lbs of boost. Can my stock rods handle this and should I change my pistons? My pistons are only good for a .540 lift with the tfs. What should I do?
need help
- Thread starter ms93gt
- Start date
Michael Yount
Mustang Master
Peak lift has nothing to do with p to v clearance - sounds like you need a little 'educatin' before you start putting things together.
How did your custom cam modeler do the job without knowing for sure what the compression ratio was?
The stock pistons in the 93 are hypereutectic -- they don't like the combination of boost and detonation; so keep your tune conservative (rich) so detonation doesn't occur. Rods are plenty strong. The weak links for you are pistons, and the stock block.
How did your custom cam modeler do the job without knowing for sure what the compression ratio was?
The stock pistons in the 93 are hypereutectic -- they don't like the combination of boost and detonation; so keep your tune conservative (rich) so detonation doesn't occur. Rods are plenty strong. The weak links for you are pistons, and the stock block.
Its the tfs valve springs they don't recommend going over .540 lift. You'll be swapping them out for real springs regardless. Now, those pistons I dont know much about. Do they have deeper reliefs for large cames and valves? I would swap those pistons out for something that you know will work and fit those heads and a larger cam. I like probe pistons because their cheap and have deep reliefs for TW and inline valves.
I'd upgrade to arp rod bolts along with whatever necessary work to make the arp bolts work.
I'd upgrade to arp rod bolts along with whatever necessary work to make the arp bolts work.
Curse
Member
ms93gt said:
Michael has forgotten more about cars than you probably will ever know. He tries to give you some advice and this is how you thank him?
And just incase you don't know, Speed Pro makes both hyper pistons and forged, you didn't say which you were getting.
Curse said:Michael has forgotten more about cars than you probably will ever know. He tries to give you some advice and this is how you thank him?
And just incase you don't know, Speed Pro makes both hyper pistons and forged, you didn't say which you were getting.
Read my post it clearly states speed pro forged pistons. And I didn't say I was getting any, I said I had.
Michael Yount
Mustang Master
"My pistons are only good for a .540 lift with the tfs."
This is the statement that indicates a lack of understanding about the relationship between p to v clearance and cam specs, specifically lift. If you want to know more about it, let us know and we'll post more. Suffice it to say that at peak valve lift, the pistons are WAY down the cylinder.
I'll stand by my spelling of 'educatin' -- it seems appropriate in this case - the fact that you didn't get 'it' makes the point.
This is the statement that indicates a lack of understanding about the relationship between p to v clearance and cam specs, specifically lift. If you want to know more about it, let us know and we'll post more. Suffice it to say that at peak valve lift, the pistons are WAY down the cylinder.
I'll stand by my spelling of 'educatin' -- it seems appropriate in this case - the fact that you didn't get 'it' makes the point.
Thenemesis
Member
hell michaels southern.. it taint right to be burstin a feller ovar his spelin 
and you can run a 8-10 lbs of boost on a stock car.. its when you start like 12lbs is when you run into problems.. the b trim and A trim.. 8-9 lbs.. are ment for just bolt on situations with no real modifications from what i have been told by many.. please correct me if im wrong
and you can run a 8-10 lbs of boost on a stock car.. its when you start like 12lbs is when you run into problems.. the b trim and A trim.. 8-9 lbs.. are ment for just bolt on situations with no real modifications from what i have been told by many.. please correct me if im wrong
Michael Yount
Mustang Master
Even the lower boost units can be problematic for guys running the stock hypers if the tune goes lean...
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