spacer plate vs. milling head and other ?'s

[desgre90]

For those who don't know I bought a blaster bottom end off of a friend. I wasn't sure what the insides were like until I took it apart. Found one of the side cases was broken in a small section . I noticed the rod said hotrods. I also noticed the bottom end casing was slightly machined (which lead me to believe it was a stroker crank), later on I found a spacer plate in another box of stuff I bought off of him that is bent (from other stuff squishing against it) which lead me again to believe it is a stroker crank. I went to the hot rods website...

Hot Rods, Inc.

and it says that the head chamber area needs to be machined 2mm. Also I assume this is because the piston is going higher... if I bore the jug, does the width of the head chamber need changed as well, does the gasket need opened up too? Is it better to just put a spacer plate in? If so, what size.

If you couldn't of guessed it, I am a n00b... but I am a quick learner.

Here was the bottom end as I got it. You can see it being machined around the rod, and the rod says hotrods. If it was the stock crank, I don't understand why they would machine it there, and inside the case like they did.

And here is where it is currently.

My plan is to order the parts (new bearings, oil seals, gasket kit) to completely rebuild the bottom end, and have the cases back together by easter weekend. But just trying to prepare for the top end at the same time. If I need the plate I will just order it, but if I need the head machined I need to be able to explain it to my machinist while he does the jug too. Any and all help is appreciated

Thanks in advance,
Greg

 

[xjma]

I'm no expert but I think that you need the spacer for the stroker crank. You wouldn't want to mill the head because that would bring it closer to the piston. As I understand it, if you don't run the spacer the piston can hit the head.

 

[desgre90]

I'm no expert but I think that you need the spacer for the stroker crank. You wouldn't want to mill the head because that would bring it closer to the piston. As I understand it, if you don't run the spacer the piston can hit the head.

Thats what I was figuring too, which is why I asked if the head chamber width had to be changed as well if you were to machine it. That is why I feel like I am hung out to dry for the moment because the hotrods doesn't mention a spacer plate, they just say to machine it. Vitos kit has a 1.5mm spacer for 3mm crank. This is a 4mm crank so do I need a 2mm spacer to solve the problem. I certainly do not want to guess after all of the money I am dumping into this motor. I am sure there have to be plenty of people with the hot rods crank that can chime in and tell me for sure.

 

[brandoz28]

i would just have the head cut and redesigned so you know its right

 

[xjma]

Not sure, never done a stroker. You could assemble it and see (not run it, just turn it over by hand and check clearances.

 

[blasterdemon7]

It will not work till you use the spacer or the best way,get the head done for a stroker.You need to find out if it is a +3 or+4.

 

[desgre90]

It will not work till you use the spacer or the best way,get the head done for a stroker.You need to find out if it is a +3 or+4.

Hot rods only does a stock, or a +4.

 

[blasterfreek30]

there is nothing wrong with using the spacer plate ive been going on 2 yrs with no issues....u do not want to cut the head in place of the spacer plate....allowing the piston to actaully go into the cut head will make alot more heat and could lead to possible warpage and a never sealing gasket suface

 

[yb200]

there is nothing wrong with using the spacer plate ive been going on 2 yrs with no issues....u do not want to cut the head in place of the spacer plate....allowing the piston to actaully go into the cut head will make alot more heat and could lead to possible warpage and a never sealing gasket suface

thats the way my head is.....on my stock stroke......no problems at all

 

[blasterfreek30]

thats the way my head is.....on my stock stroke......no problems at all

yea but with ur stock stroke the piston isnt going into the head +3 or +4 mm

 

[yb200]

yea but with ur stock stroke the piston isnt going into the head +3 or +4 mm

true idk how far it goes in ill have to ask my builderI:I

 

[blasterfreek30]

true idk how far it goes in ill have to ask my builderI:I

well if u look at ur avatar u can see u still have a gasket surface and ur piston is only gonna go as far as TDC....so milling it just drops the head closer to the piston, ur piston is not going into the head...im sure just the squish angles were changed for the poorly design stock head specs

 

[yb200]

nope it goes in to the head....it comes up out of the cylinder unlike a stock setup

 

[Kennedy_Power]

For those who don't know I bought a blaster bottom end off of a friend. I wasn't sure what the insides were like until I took it apart. Found one of the side cases was broken in a small section . I noticed the rod said hotrods. I also noticed the bottom end casing was slightly machined (which lead me to believe it was a stroker crank), later on I found a spacer plate in another box of stuff I bought off of him that is bent (from other stuff squishing against it) which lead me again to believe it is a stroker crank. I went to the hot rods website...

Hot Rods, Inc.

and it says that the head chamber area needs to be machined 2mm. Also I assume this is because the piston is going higher... if I bore the jug, does the width of the head chamber need changed as well, does the gasket need opened up too? Is it better to just put a spacer plate in? If so, what size.

If you couldn't of guessed it, I am a n00b... but I am a quick learner.

Here was the bottom end as I got it. You can see it being machined around the rod, and the rod says hotrods. If it was the stock crank, I don't understand why they would machine it there, and inside the case like they did.

And here is where it is currently.

My plan is to order the parts (new bearings, oil seals, gasket kit) to completely rebuild the bottom end, and have the cases back together by easter weekend. But just trying to prepare for the top end at the same time. If I need the plate I will just order it, but if I need the head machined I need to be able to explain it to my machinist while he does the jug too. Any and all help is appreciated

Thanks in advance,
Greg

Before I finish reading all the post
Dude these are great questions
I will finish reading it all now

 

[blasterfreek30]

nope it goes in to the head....it comes up out of the cylinder unlike a stock setup

how???.....is the jug milled down by the base gasket surface or at the top where the head bolts on??...the piston crown will come out of the cylinder mabe 2 or 3mm..but i dont see how unless the stroke is longer

 

[bag0b0nez]

well dude this is what i would do. take ur cylinder and send it to one of the lovely builders on this site. i think kennedy will get it sent back earlier then the others. atleast when i checked he was the fastes. but u need to get your ports cut for the +4 mm. i have a 3mm and i just got my cylinder ported for it. cause them spacer plates are junk. when u put a 3 or 4 + in it throws ur ports off which means sh*ts not gonna fire right. which also means ur going SLOWER then what it originally would be. im sure a builder will agree with me the best way to make that 4mm stoker scream is to get a port and polish built around it. and also about ur head gasket on my old blaster i bored it .80 over and i had to shave my head gasket cause it had a lip. not shave the up and done talking about the circular part that hangs over the cylinder

 

[Kennedy_Power]

This what I will say. A 4mm stoker to do right is a biotch. The piston goes up 2mm and down 2mm more then the stock crank(57mm) u know have a 61mm crank..
With the additional stroke and if you use a spacer plate it will jack up your transfer timing. It will not be even close to where it needs to be. The cylinder head needs to be completely redesigned. It is a tough project... If you do not want the pain u already might feel. use a stock stroke....

 

[blasterfreek30]

nope it goes in to the head....it comes up out of the cylinder unlike a stock setup

kennedy.. can u explain yb's setup alittle better.....

 

[yb200]

kennedy.. can u explain yb's setup alittle better.....

maybe its a builders secret

 

[blasterdemon7]

This what I will say. A 4mm stoker to do right is a biotch. The piston goes up 2mm and down 2mm more then the stock crank(57mm) u know have a 61mm crank..
With the additional stroke and if you use a spacer plate it will jack up your transfer timing. It will not be even close to where it needs to be. The cylinder head needs to be completely redesigned. It is a tough project... If you do not want the pain u already might feel. use a stock stroke....

I take it that it's the same for a +3 to.Is it worth adding a stroker crank?How much more power will it add.I know it adds torque the most but how much?