Its Retarded! Why?

FlatheadsForever87

FlatheadsForever87

Member
Sometime last week I purchased a new to me Raptor 3 from a local Bob's 4 cycle fella. Price was right hell why not. Upon external inspection all seemed to check out A Ok. Noticed later that the carb is cracked in the rear air horn area, fuel tank bowl was rusted out ect. But that's besides the point. Next day I removed the head, crankcase cover, valve cover, carb from block and from tank, and flywheel for a thorough inspection. These are my findings so far...., 08' ARC Billet rod, std bore piston, cylinder due for rehome, blocked decked minimally piston pop up back of cylinder and in the hole on front, head milled very lightly, ground cam, welded lifter bore area, champhered lifter bores, spring pockets cut, after market billet valve cover hose hold down, 3 bolt overhead carb saver, aluminum velocity stack, 5 degree flywheel key, 3 stage behind the seat header with Stock RLV silencer with Rlv silencer clamp, that's all I can think of for now.

The issues i have had are simple things but could have been a real headache if I hadn't luckily approached it with a somewhat experienced mindset. The Long brass pick up tube had a very small hairline fracture running halfway down it. I am so grateful I solved this issue so easily. Because this time last year this issues would have tested my character to a point I'd rather not admit. Lol. Second thing I noticed was there was not the tell tale valve float scar on the head. Couldn't imagine why not with a ground stock cam. Lastly I noticed upon flywheel removal that the 5 degree key was, yep you guessed it, backwards. Put it in correct after lapping in flywheel. Finally I Lapped in the valves real good cleaned up everything real nice and buttoned it all back together. First pull on the rope and away she goes. So the questions I have for the pros. Was this key installed retarded intentionally? If so what was the intent? Next question is this the reason why the valve scar was not made in the head? Thanks to all who took the time to read my chicken scratch. And double thanks in advance to all that will shed light on this to my measly little brain.
 
Offset ignition keys don't just mistakenly get installed backwards by a professional builder. I suspect either someone inexperienced had removed the flywheel since it was originally built, OR the "builder" is no more than a decal.
Being retarded in timing would not allow the engine to run enough rpm to float the valves (IF they are even set up to float.)
It kinda sounds like the engine may have been built to karting standards at some point (by machine work and welding) but it had been relegated to backyard use (possibly on gas) that caused the previous owner to change the jet and think that backing some timing out of it would help on gas (=incorrect thinking.)


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
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34 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Yeah that was pretty much my thoughts on it as well. It was still jetted for alchohol when i bought it. It was supposedly the mans back up engine that was barely used by him. I just wonder how long it was ran with retarded timing before he bought it because the cylinder needs a hone due to lack of cross hatch. Other than that there is zero scoring or anything. Does have the normal lip on top of cylinder. So it has obviously been ran quite a bit. Definitely enough to have had a wear mark on the head from float.


Installed on mini bike and ran for few nights. Honestly I am quite impressed with it. It actually had me picking my self up of the road the first time out. I think I'm in love. Lol. "
Compared to my other FH with a Dover DX3 cam (I think that's right) which doesn't rev out super quick, I was told was a cam for really big momentum tracks. Instead this new FH seems to really want to get maxed out in a hurry. And it fits my application very well. Is it only the cam difference or is there other factors in the equation? Such as springs and or timing ect.
 
Springs control when the valve floats (above 6300 rpm.) Cam can be a difference to an extent, but if it's a WKA grind, they're all so very close that I doubt that's what you are feeling. Fueling, ignition timing, and pipe all have an affect on where the torque curve is as well. Something as simple as installing a longer pipe with a smaller ID can bring alive an engine from 0-30mph.
 
builder stickers mean very little. i saw a minimum of 6 different flatheads from several different builders with different set of names carved into the front of them. most of these motors have been around the block for quite a while. and the tins can migrate from motor to motor. nothing stopping anyone from slapping Chavis tins on a dud motor and passing it off for good money.
 
J'-remy said:
builder stickers mean very little. i saw a minimum of 6 different flatheads from several different builders with different set of names carved into the front of them. most of these motors have been around the block for quite a while. and the tins can migrate from motor to motor. nothing stopping anyone from slapping Chavis tins on a dud motor and passing it off for good money.
Click to expand...
= FACT.
This happens all too regularly.
Most builders will keep records on their engine builds, when it was last through their shop, cam, bore size, etc, and be able to tell you about a specific engine. If they haven't seen the engine in several years, chances are that someone else has gone through the engine since them.
All of our blueprinted engines have a number stamped in the block to the left of the rear oil drain plug. (note: We do not stamp LO206 engines.)
With that number, I can tell you just about everything inside of that engine from the last time that we built it.
 
My ROLLS ROYCE sticker on my OLD POS blazer really looks good ;) as does 6.7 L TURBO DIESEL ... sticker. the BMW EMBLEM ($3 on e bay) fit/epoxied just right in the round hole on the front of the... Buick
 
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