Harley Davidson Forums banner

1 - 20 of 33 Posts

·
Village Idiot
Joined
·
2,300 Posts
Discussion Starter #1
I finally got the paper listing the specs on the head work I had done during my rebuild this past winter. I am not real sure what it means (I understand flow, but I have not seen a sheet with so many entries) I posting it here in hopes that someone much smarter than I am can help me decode it and know what numbers are really important. The sheet says "Stage 2 Port" and calls the intake and exhaust valves sizes "Stock Stage 2". As well, it shows the flow numbers at, what seems to be, various valve openings? What does that tell me about this set of heads? Valve sizes and what flow.

Was from my '01 FLHTCUI that had a 95" kit put on it. This rebuild included these modified heads, the 95" cyls bored .020 and 10.5:1 Wisecos installed, new updated (OEM) crank assembly with all new lower bearings, new OEM hydraulic lifters w/adjustable pushrods, SE 203 cams, PCIII set up on the stock M&M FI system, and 3.5" Rinehart True Duals.

Is this an OK set up for mid-range torque? Is a new cam in order here? What would be recommended? This is the first build I have had done and is definitely a learning experience. Sorry for rambling, I seem to have ADD and needed to get all my questions out before I forgot them. Thanks for any advice you could give. :eek:uttahere:
 

Attachments

·
Village Idiot
Joined
·
2,300 Posts
Discussion Starter #2
Oh, it also had the stage I kit on it, too, so Air flow shouldn't be an issue.
 

·
Registered
Joined
·
769 Posts
well they have it listed in 10" water most places list 10 or 28, these are the common listings

going off of what they have written down your max flow is 289 cfm at 28 on intake and 223 cfm on exhaust and these numbers are on stock factory valve sizes and this place that did your head is calling it there stage 2 head, some places may call a stage 2 head with somthing that has oversized valves, different places represent there stages differently in some cases,

these heads are great and will work on a 95ci motor BUT lets look at your cam....203 cam has max intake lift of .510 and exhaust of .483 ...now lets also take into account that this is on a rocker ratio of 1.65:1 ...however if use stock harley rocker arms, your ratio is only 1.625:1 this means you are getting even less lift

so intake becomes .502 lift and exhaust is .475 so now the numbers you need to look at are no longer peak flow at .55 lift but rather flow at .5 on intake and .475 on exhaust

now 280 and 209.5 cfm from this you can find the POTENTIAL hp of the motor based off of flow ALONE
but in my oppinion for stock size valves these numbers are really high, most people are getting around 230-240 on stock valves

if you go to this site Chart-Twin Cam 88
they show there flow chart and this is what most places put out some may give alittle more or less in spots but you can only do so much on a stock valve size

also this site lists there flow chart at 10" even though its not listed, and if wanting to convert to 28 then you multiply by 1.67 i beleive

if your heads truely flow the listed numbers i would buy a cam with atleast .550 lift and spin it upwards of 6500 so perhaps a cam like the 258 or 260 if going with SE parts, personaly i would go with 260 over 258 if it was my bike, but make sure you have an exhaust tuned for higher rpms, along with the proper valve springs, pushrods, lifters, and a crank that is welded and ballanced

OR shove a big high lift midrange cam in from woods and be happy with what you end up with,

one more note, becareful with 10.5 pistons and that 203 cam, u r not bleeding much compression off and may get into issues with bad gas, hell even good gas if you dont have it tuned well
 

·
Village Idiot
Joined
·
2,300 Posts
Discussion Starter #5
these heads are great and will work on a 95ci motor BUT lets look at your cam....203 cam has max intake lift of .510 and exhaust of .483 ...now lets also take into account that this is on a rocker ratio of 1.65:1 ...however if use stock harley rocker arms, your ratio is only 1.625:1 this means you are getting even less lift

if your heads truely flow the listed numbers i would buy a cam with atleast .550 lift and spin it upwards of 6500 so perhaps a cam like the 258 or 260 if going with SE parts, personaly i would go with 260 over 258 if it was my bike, but make sure you have an exhaust tuned for higher rpms, along with the proper valve springs, pushrods, lifters, and a crank that is welded and ballanced

OR shove a big high lift midrange cam in from woods and be happy with what you end up with,
Suggestions on a big high lift mid range cam?

I must say that it has all kinds of torque as it is set up now... I am guessing that a new cam will improve the numbers a bit AND will reduce the the issue of detonation, too, don't you think?
 

·
Village Idiot
Joined
·
2,300 Posts
Discussion Starter #6
Pretty impressive considering stock valves. What year heads are these?
These are from an '01 (FLHTCUI) TC-88 upgraded to Stage II (95"). I believe the valve sizes are I: 1.85" and E: 1.565"
 

·
nitro freak
Joined
·
1,264 Posts
i really wouldnt go off this chart for choosing a cam.with stock size valves,im not buying the numbers
 

·
Village Idiot
Joined
·
2,300 Posts
Discussion Starter #8
i really wouldnt go off this chart for choosing a cam.with stock size valves,im not buying the numbers
I trust and respect your input alot, thanks for weighing in. So, do you feel that the guy isn't being straight with me, or that his numbers are just plain wrong?

I finally did get ahold of the actual machinist this afternoon and he says that these are the numbers, but he gave me 1.800" for intake and 1.575" for exhaust. The specs that I looked up showed that to be in 05 and later year model heads and the ones I put in to be for '99-'04 heads. Is that right?

End of the day, I am not racing it, I am happy with the way it passes now, but I don't want to cause further damage to the engine. If I need to get the 203 changed out then what is a good safe bet that would work with this combination?
 

·
nitro freak
Joined
·
1,264 Posts
173 CFM @ 10" with a stock size valve is almost impossible,but dont get hung up on the numbers,a good tuner wouldnt even look at a flow chart for tuning
 

·
Registered
Joined
·
769 Posts
i really wouldnt go off this chart for choosing a cam.with stock size valves,im not buying the numbers
im glad im not the only one thinking this...they seem high after .300 lift
 

·
Registered
Joined
·
769 Posts
I trust and respect your input alot, thanks for weighing in. So, do you feel that the guy isn't being straight with me, or that his numbers are just plain wrong?

I finally did get ahold of the actual machinist this afternoon and he says that these are the numbers, but he gave me 1.800" for intake and 1.575" for exhaust. The specs that I looked up showed that to be in 05 and later year model heads and the ones I put in to be for '99-'04 heads. Is that right?

End of the day, I am not racing it, I am happy with the way it passes now, but I don't want to cause further damage to the engine. If I need to get the 203 changed out then what is a good safe bet that would work with this combination?
odd he would put in smaller then stock valves...and shouldnt matter the year, they didnt change port design till 06
as far as changing cam you would need to check piston to valve clearance and valve to valve clearance

and i would look into somthing like the woods W9 cam...has good lift and duration for your piston and higher revving 95 motor...you shouldnt lose much on bottom but will gain alot on top...still be fun around town or on the highway either way you will be smiles
but you will need springs n to check clearances...should pull to 6300 + or - few hundred rpm depending on how good the heads really are and the exhaust used
 

·
Maddog
Joined
·
394 Posts
173 CFM @ 10" with a stock size valve is almost impossible,but dont get hung up on the numbers,a good tuner wouldnt even look at a flow chart for tuning
That's what I was thinking too. I got close to 170 but that was
with a 1.94 intake and port welding. (It suffered a little at .2-.3
as well)
 

·
Village Idiot
Joined
·
2,300 Posts
Discussion Starter #16
Just got the news that she has to come apart again. Sadness... Oil pooling on top of the front cylinders and a camera through the plug holes reveals some serious scoring on the cylinder walls (front & back) with only 2,000 miles since assembly. Builder readily said he will redo cyls and pistons & rings when I told him about it. I'll give him credit for that. I am mostly bummed about the down time again, but better to find and fix it now than later.


Sent from Motorcycle.com App
 

·
nitro freak
Joined
·
1,264 Posts
while the heads are off,if you want to send one down to florida,ill put it on my flowbench to check the #`s
 

·
Kicking Rocks...
Joined
·
11,113 Posts
while the heads are off,if you want to send one down to florida,ill put it on my flowbench to check the #`s
If'n I was you I'd be all over this offer...

:thumbs
 

·
Village Idiot
Joined
·
2,300 Posts
Discussion Starter #20
while the heads are off,if you want to send one down to florida,ill put it on my flowbench to check the #`s
Kirby, i appreciate the offer, PM me the address and I'll check with the tech to see if he can do it. I know that I will be out of town almost all of May so the extra down time may not hurt me. I'd sure love to see what the real story is here.


Sent from Motorcycle.com App
 
1 - 20 of 33 Posts
Top