I need some knowledgeable opinions on 61x versus 62T -64X cylinders

[WFO Speedracer]

I need to build an engine for my SN Superjet build and am looking ahead a bit .

I have an opportunity to get a set of nice 62T cases and cylinder that needs boring , I also have a 760 cylinder , OEM dual 44 intake and carbs to go with it , I also have a complete 61x motor and a set of dual 44 carbs and an intake for it .

I am older than dirt and had a hip replacement so most likely I won't be doing backflips and barrel rolls , just general riding and wavechasing mostly , I have a Coffman pipe and an aftermarket manifold and stock ignition components I am going to use .

I understand the 61X top end will probably have more bottom end snap than the 62T or 64x , but if I am not doing tricks do I really need it , anyone who has run both setups , which is better for general riding and why ?

I think I lean more toward mid range and top end power but I do still want some pop out of the hole , I am looking for suggestions here so , let er rip .

 

[kevbo]

The low port cylinder is much easier to make work. It will be more responsive but a little slower at top speed. The exhaust port should be widened, especially if you have a pair of 44s. High port cylinders will have you always looking for better response. You can get it with a flatter impeller, compression, and a zeel ignition.

 

[E350]

Kevbo, so is the best low rpm torque set up putting a 61X cylinder on top of a 62T crankcase?
And do they just bolt on without any modification necessary?
(Assuming that the pistons are the correct size . . .)

 

[WFO Speedracer]

Kevbo, so is the best low rpm torque set up putting a 61X cylinder on top of a 62T crankcase?
And do they just bolt on without any modification necessary?
(Assuming that the pistons are the correct size . . .)

A superjet engine is exactly that a 62T case with a 61X cylinder on top of it , yes it does bolt straight onto the 62T cases .

A 64X cylinder will also bolt on to 62T cases if you enlarge them a tad, I have done a few like that before.

 

[waxhead]

A 701 62t is way better. By the time you port a 61x to make power you actually go past a 62t anyway. the reality id you can widen the exhaust port on a 701 62t and set the squish correctly, put some decent carbs, pipe on it and away you go.

 

[WFO Speedracer]

A 701 62t is way better. By the time you port a 61x to make power you actually go past a 62t anyway. the reality id you can widen the exhaust port on a 701 62t and set the squish correctly, put some decent carbs, pipe on it and away you go.

I don't mind doing some mild porting - cleanup but I don't want to get crazy with it , I too have heard good things about the 62T setups .

 

[waxhead]

I don't mind doing some mild porting - cleanup but I don't want to get crazy with it , I too have heard good things about the 62T setups .

The 61x will not have more bottom end snap than the 62t 701, the transfers are to blocked from the factory. you are more than capable i know but you can also download and print our porting templates off the site

 

[kevbo]

There are not many impellers flat enough for high ports and pump gas. Most riders will never know the difference that an additional 200 RPM can make in power response. If they did there would be a LOT more discussion on this subject.

 

[waxhead]

There are not many impellers flat enough for high ports and pump gas. Most riders will never know the difference that an additional 200 RPM can make in power response. If they did there would be a LOT more discussion on this subject.

A stock 62t is 118 transfers the same as 61x except they are not closed over with casting. The exhasut is where it differs and the 61x is 179 vs 182 on the 62t basicakkt the 62t is a cleaned up 61x with slightly higher exhaust. It will make more power every where. if you widen up the exhaust to say 65% bore width and take the squish to .8mm you will have a hot little package that will hit way harder than a lot of the full on engines out there. I have done this plenty of times and it freaks people out. The 701 62t cylinder is a majorly underated cylinder

 

[WFO Speedracer]

There are not many impellers flat enough for high ports and pump gas. Most riders will never know the difference that an additional 200 RPM can make in power response. If they did there would be a LOT more discussion on this subject.

Kevbo while I appreciate your response it's always the same, pump load , pump load , pump load , sorry but there are way more variables to consider than just the pump load , I am just saying it's time to get some new material.

 

[E350]

@waxhead I have a two carb 62t out of a 96 WaveVenture 700. Would you mind either posting a thread or linking to info on how to to port it and to modify the squish.

BTW, since I have the waterbox out of the FX-1 now (it is not the source of my jumping up rpm problem) because the water box is studly.

So I am in the process of putting the B Pipe with your manifold and headpipe as I write this.

but I may be putting the 62t into the FX-1 and would like to modify it before I do.

Just asking for a friend . . .

 

[waxhead]

OK, but its sunday morning here and the suns out, can i do it later but really happy to do it and you will be surprised what you can do, I did this exact engine in a fx1 and it was awesome. so playful and so reponsonsive. I love over powered skis but the fx1 with this engine is an amazing thing

 

[E350]

Take your time.

I found the Bpipe for the FX-1, I found your head pipe, but for the life of me I am still looking for your 61x exhaust manifold. I bought it, it shows on my orders, I remember receiving it and shelving it, so I have it, I just need to find it !!!

So, go ski and when you have time post up your thread on modifying the 62t. I have a Bpipe for it, but I will need to buy your water box connector, pipe coupler, headpipe and your exhaust manifold and trick exhaust manifold bolts for the 62t.

 

[waxhead]

lol sounds like my garage

 

[kevbo]

Kevbo while I appreciate your response it's always the same, pump load , pump load , pump load , sorry but there are way more variables to consider than just the pump load , I am just saying it's time to get some new material.

I would talk about carburetors and loud mufflers like everyone else, if it actually made an improvement. Do you know your port heights? How far will your pipe rev before it goes rich? What RPM are you turning? The last question is answered by the impeller. It’s the one item that is relatively easy to change. Yet nobody wants to do it! I tried to get riders interested in hull dimensions, that also fell on deaf ears.

 

[john zigler]

62t is by far my favorite. We learned this many years back from switching couch engines into to Sqaures. They run really good! Easy to do a quick port match, but even left alone they can really run well. Personally I am not a fan of the stock 44's. I would go stock 38's, or if you do want 44's go aftermarket. It is worth the change.

 

[WFO Speedracer]

I would talk about carburetors and loud mufflers like everyone else, if it actually made an improvement. Do you know your port heights? How far will your pipe rev before it goes rich? What RPM are you turning? The last question is answered by the impeller. It’s the one item that is relatively easy to change. Yet nobody wants to do it! I tried to get riders interested in hull dimensions, that also fell on deaf ears.

Since I haven't put the engine together yet , yeah the answer would be no , as far as the deaf ears go, when you keep beating the same drum for years and years that tends to happen.

 

[WFO Speedracer]

Take your time.

I found the Bpipe for the FX-1, I found your head pipe, but for the life of me I am still looking for your 61x exhaust manifold. I bought it, it shows on my orders, I remember receiving it and shelving it, so I have it, I just need to find it !!!

So, go ski and when you have time post up your thread on modifying the 62t. I have a Bpipe for it, but I will need to buy your water box connector, pipe coupler, headpipe and your exhaust manifold and trick exhaust manifold bolts for the 62t.

You will find it when you are looking for something else.

 

[Alectravis]

There are not many impellers flat enough for high ports and pump gas. Most riders will never know the difference that an additional 200 RPM can make in power response. If they did there would be a LOT more discussion on this subject.

What is your definition of a flat impeller and what is considered high port?

 

[WFO Speedracer]

My thinking is that the 62T cylinder will lose a bit on top end compared to the 64X cylinder and have slightly softer bottom end than a 61X and I am ok with those tradeoffs , for what I am doing with this ski I believe it will do just fine .

I also have to look at resale , I may not keep this ski, I won't know till I get it built and ride it for a while , that being said I don't want to venture too far from stock on a ski I may not be keeping .