andrews 26 cam in 95 build

[Fisherking]

Ok my bike is fi . Stock 88 set up .with a stage one I got a set of forged cp pistons 9 cc dome . I have another set of jugs to bore out for a 95 build with stock heads with low k . I'm trying to make it work with the less stress on the engine. Low lift cam .
I have a cobra 2 tuner on it .
How will this set up pull throughout the whole rpm range as compared to my stock set up 88 with stage one .
Sorry for being all over the place . I just want the engine to breath right . And been trying out the com p calculator
.
If I put a tw 50 on it with this set

I was wondering who has a tw50 cam in thier 95 set up with high compression .
How does it pull through all ranges compared to a reg 88 set up with a stage 1 .
Thanks f.k.

 

[dolt]

Ok my bike is fi . Stock 88 set up .with a stage one I got a set of forged cp pistons 9 cc dome . I have another set of jugs to bore out for a 95 build with stock heads with low k . I'm trying to make it work with the less stress on the engine. Low lift cam .
I have a cobra 2 tuner on it .
How will this set up pull throughout the whole rpm range as compared to my stock set up 88 with stage one .
Sorry for being all over the place . I just want the engine to breath right . And been trying out the com p calculator
.
If I put a tw 50 on it with this set

OK, now I think I am getting the picture. You have the 3.885" bore CP pistons with a 9cc dome and a set of OEM cylinders that you will have bored to fit those pistons and you have a set of stock heads. You have a Cobra tuner but which one? Fi2000r, Fi2000r Closed Loop of Fi2000r Power Pro? None of the Cobra tuners are setup for dyno tuning and unless yours is the Power Pro, they are pretty much useless. You would benefit from a real fuel management system; a flash tuner like the Powervision or the TTS Mastertune and a dyno tune.

Your ultimate goal is more low and mid range power and you are not too concerned with high end of the rpm range; the priority is the low and midrange which is the right approach IMHO as that is where most of us ride.

Assuming head work is not in your plan, here is what I would do and I am sure you will get plenty of suggestions.

Have the machinist that is boring your cylinders also machine the piston dome down to 5-6cc and make a set of TW37 cams part of the plan. Replace the inner cam bearings with Torrington B-148 bearings and replace the cam chain tensioners with the CYCO units. Install the Baisley pressure relief valve spring in the cam plate for a little more low range oil pressure. Use a .030" Cometic MLS head gasket to tighten up the squish band and call it good.

As I mentioned, you really should consider putting the Cobra tuner on Ebay and purchasing a better tool; the tune will make all the difference. You cannot adjust timing with any of the Cobra units and some timing adjustments may be necessary for a proper tune.

This combination will pull hard but you will need headwork to get close to 100TQ/100HP; can't do it without head work but the bike will run much better than your 88"er.

If budget will allow head porting, we are talking about new springs that will accommodate higher lift cams; different ball game and more cames to choose from.

BTW, the TW50 duration of 248/250 will not perform well in the low and midrange; it's more of a higher rpm cam.:s

Another option to run the TW37 without machining the piston dome would be to run the cam retarded 4* and a .040" head gasket.

You haven't mentioned exhaust; what are you currently running?

The most important part of any build is the final tune; you really should consider replacing the Cobra system with something better. JMHO

 

[Fisherking]

I'm running vance and hines long shots

I might have to do the tune after the build .
Ill have to see what I can aford .
Now there are settings using a #2 down load ?

I like the sound of of taking the pistons down to 5 . Would that make a thin spot on the piston were it might blow through or is the dome solid . I do thinkthe tw 37 is the way to go .
How much do those tuners go for that u mentioned earlier .
And by the way thanks for being patient. I apreciat all the help you guysare doing for me
F.k.

 

[dolt]

I like the sound of taking the pistons down to 5. Would that make a thin spot on the piston were it might blow through or is the dome solid . I do thinkthe tw 37 is the way to go. How much do those tuners go for that u mentioned earlier. And by the way thanks for being patient. I apreciat all the help you guys are doing for me.

A down loaded map will not get the tune right. Either the Powervision or the TTS Mastertune would be my choice of tuners. Talk to your local tuner and see what he likes to use.

TTS Power you can bank on!

Dynojet Power Vision Product Details


Mastertune runs about $445 and the Powervision about $545. The both have a "self tune" feature and a large library of maps for down loading to get a baseline tune to run if you can't get the bike on a dyno right away after the build which would be my advice. Most tuners will do a couple of moderate pulls to check that the AFR is OK for break in; a good tuner can seat the rings on a dyno. After 1000 miles, take the bike back for a final tune.

I have removed a 3cc dome from a set of 4.125" CP pistons to make them flat tops with no issues. I don't think there will be any issues shaving the 9cc dome down to 5cc but you can always give CP a call; their tech guys are happy to answer customer questions.

The V&H Longshots are not the best power makers; a Propipe, Bassani RR II or D&D Fatcat or even the new Rinehart 2:1 pipe would all be better but perhaps that's a future upgrade?:s

 

[Fisherking]

I figure about the vance and hinse but they sound so good lol

I was checking on an octane chart.IS it related to static compression or corrected compression. Because corrected compession is at 9.43:1 . Will I be able to run 92 oct or 94 oct all the time .?
Static compression is somewere around 10.38 :1

 

[Fisherking]

I have been playing with the compression calculator and these are the numbers i'v been looking at
If I shave 2.5 cc.030 head gasket , so a 6.5 dome tw37 ,- 4º on the cam I'm getting
Static comp, 10.28:1
Corected comp, 9.36:1
6 CC dome
Static, 10.22:1
Corected, 9.31:1
What octane can I use. Could I get away with 92 , octane all the time and 94, oct when I can . How would this be in the summer . 75-90 ºf on average

 

[dolt]

I have been playing with the compression calculator and these are the numbers i'v been looking at.
If I shave 2.5 cc.030 head gasket , so a 6.5 dome tw37 ,- 4º on the cam I'm getting
Static comp, 10.28:1
Corected comp, 9.36:1
6 CC dome
Static, 10.22:1
Corected, 9.31:1
What octane can I use. Could I get away with 92 , octane all the time and 94, oct when I can . How would this be in the summer . 75-90 ºf on average.

JMHO but I would forget running the -4* cam sprocket and reduce the dome to, say 5cc, or whatever required to set the corrected CR at 9.3-9.4 or CCP about 185-190psi; keep it simple (don't forget to adjust for sea level when using the BB calculator).

My '02 FLHT, all bore 107 has compression set at 9.4 and CCP is between 185-190. I have run that motor on 87 octane most of the year but when summer temps start approaching 100*, I run 93. Never tried to run 89 octane in the hot summer months; just don't feel like taking a chance for an extra $2 a tank.
You should have no problems running 92 provided the motor is properly tuned.:s

 

[Jack Klarich]

I don't want to sound fussy, but I would weigh both pistons before and after milling them JMO

 

[Fisherking]

Hey Jack that's good advice.
Yes Dolt , with a 5 cc dome running andrews tw37 cams the ,
Static comp is 10.12:1
Correct comp is 9.38:1
Cold cranking comp at 1000 feet is 189.6
This is without retarding the cam .
Now is the tw 37 cam the same grind as the tw37b cam
Thanks Dave

 

[dolt]

The 37B is the correct cam for '99-'06 TC88s; 37H is for '07 and up and 37N is the conversion cam.

Any machinist that knows what he is doing will weigh the pistons before machining and weigh them after. It would also be advisable to weigh the CP piston, pin and ring pack and compare it with the weight of the OEM piston, pin and ring pack. The two weights should be within 10% of each other to maintain crank balance within the balance factor. Should not be an issue with a CP piston but always good to check.

There are two ways to accurately reduce the dome volume; both are trial and error.

Volume Measurement
1. Install the CP piston near the top of the cylinder with the top ring installed; the cylinder should be level on the bench. Position the cylinder, say 1" from the deck; measure with a depth gauge. Fill the gap between the top of the piston and the ring with ordinary grease; this will insure that the measuring fluid does not leak by the ring. Place a piece of plexiglass with a hole in the center over the top of the cylinder. From a large syringe or burette filled with a measured volume of fluid, rill the void with ATF or similar fluid via and note the volume of the fluid required to fill the voids.

Now calculate the volume of the cylinder from the deck to the 1" depth.

3.14 x (3.885/2) squared x 1". The difference in the two volumes should be the dome volume. Just because the dome volume is specified to be 9cc doesn't mean it is exacly 9cc; it will be close, maybe dead on but to get to 5cc or wherever, you need to know the starting place.

2.Remove the piston and take a measured pass or two and remove say .030" from the top of the dome, or whatever the machinist chooses with the milling tool and repeat the above procedure. Now you have a directly proportional relationship between the amount removed from the dome and the associated volume. The machinist now knows how much to remove from the dome to get to 5cc. Once there, a final measurement should be taken to verify.

Weight Measurement
Using the weight of 1cc of aluminum at .952 ounces, weigh the piston sans pin and rings; mill some amount, say .030" from the dome and weigh the piston again. The difference in weight relates directly to the dome volume removed.

The problem I have with this approach, while quicker, is that you don't have the actual measured dome volume as a baseline and the piston is an alloy, not pure aluminum so unless CP can provide the weight of 1cc of the piston material, the weights might be off a bit.

It is a tedious and time consuming process if one has not done it before. If your machinist is not comfortable that he can accurately shave the dome, there are places you can send the pistons to have them machined accurately.