Project: good cheap surf motor

[teton]

Alright Ive been thinking of doing this for a while, now that my senior design project is over I have the chance to put it into action. here are my plans for the motor.

after looking at some 61x reed cages vs. the 62T I noticed that the actual incoming area of the 62T's is actually smaller (at least on the v-force 1's i have) the actual reed area of the 62T is larger, but I figured hell, I bet I could build a full 61x motor just about as strong as a 62t/61x motor. I have to give Matt-E's frankenstein build credit for getting me off my ass.

so here are the plans:
-61x/61x
-bore will be 83mm
-epoxying/heavy porting of the cases
-porting the cylinder for freestyle
-the carb will be a single 48mm full spectrum
-I will be lightening the stock flywheel based on finite element analysis on
solidworks (CMOS works) so I know where its the best to remove material
-heavy boring of the stock intake.....will require epoxying

and last but not least....let me know what you guys think.....a waterjacketed intake manifold.....no idea how beneficial this will be......but I will compare it to a bored stock manifold

Im hoping from a lot of feedback from you all.

 

[teton]

so here's what ive done so far......

In order of pics...
roughed the voids in the crankcases after beadblasting
crankcase after epoxying/milling....
milling epoxy flat with sealing surface.

 

[brentR]

i never understood why epoxy the cases like that?

 

[Matt_E]

To prevent break-through when you port the intake passages.

 

[teton]

Ok its taking a little longer than I thought due to graduation. However I got the cases rough ported,they still need to be cleaned up a lot....lemme know what you guys think.

should I go more?

pictures show ported vs. stock for comparison

 

[teton]

Also I got the exhaust ports done on the cylinder, now its time to focus on how badly mismatched the transfer/boost ports are

 

[pimpchevy07]

looks good, i run a ported 61x/61x and i prefer it over the 62t/61x i had.

 

[Matt_E]

Have a look at .#0's porting specs thread.
Matching the ports should result in good Freestyle numbers.

However...there are builders whom advocate not touching the roofs of the ports, no matter how mismatched they are.
In that case, simply widen the ports.
Or, call a reputable builder who knows what he's doing.

 

[teton]

Have a look at .#0's porting specs thread.
Matching the ports should result in good Freestyle numbers.

However...there are builders whom advocate not touching the roofs of the ports, no matter how mismatched they are.
In that case, simply widen the ports.
Or, call a reputable builder who knows what he's doing.

I was talking about the the case porting, As for the cylinder, ...just cleaning them up....is that what you meant?....I'm not touching stainless on the transfers...only the aluminum.

 

[Matt_E]

I was talking transfer ports on the cylinder.

 

[teton]

hmm, well i hope what i did is ok.....no pics yet but i pretty much matched the aluminum with the sleeve on each port, and widened the ports a little

 

[#ZERO]

Awesome work! :fing02:

You're going to make that engine breathe. :brap:

 

[brett]

cheap?

 

[teton]

cheap?

I'd say so....the cases and cylinder cost me about 100 shipped....the crank i had from a 6m6...same with the flywheel and stator....the only high dollar item was the carb which i bought off project ski for 375....so far its only cost me 475. id say not too bad

 

[brett]

thats pretty cheap!

 

[teton]

by the way if anyone has any after market 61x reeds....I need them

here's the case porting with the crank in.....would shortening the boost port (removing material) have a positive effect.....i know its a lot shorter on 62t cases.

 

[#ZERO]

You should keep the boost port channel longer for bottom end.

You can increase the width from 19mm to 23mm but you would have to remove the cylinder sleeves and port evenly up to the boost port window.

 

[teton]

Alright, I know its been a while, I graduated on saturday so now I should have a lot more time to work on this build.

I finished the porting on the crankcases, I still have a couple of details here and there before I bead blast them, but the overall shape and size is where im planning on leaving it, again im open for criticism and advice from you all.

the second picture answers the infamous question of "why do you put epoxy in the voids?" well there's your answer. you can easily see all the spots where the porting ground thought the aluminum into the epoxy.

Today I also discovered how awesome carbide bits are, it took me about 3-4 hours to do one side with mounted stones, and about 1 and a half hour to do the other with carbine.....you just have to have a really steady hand because they take off a LOT of material.

I also started water jacketing the intake today, mocked up all the aluminum, but the tig crapped out on me so I only got to tack everything in place.

 

[Matt_E]

Yup, those carbide bits make short work of aluminum.

 

[Big Kahuna]

the intake is a non heat side, do not see any benefit unless it can somehow cool the incoming charge.