7M stroker build

[mk3ukr]

I started thinking about this project more then 1 year ago, actually it was in my plans to collect parts and do it in 2010, but I blew my HG last September and decided to do proper engine rebuild instead of simply replacing head gasket.
Motor will be based on SIP Racing 97mm stroked 6M crank and Turbonetics 78mm Y2K ball bearing turbo. Engine displacement will be 3.23 ltr, hope for faster spool with this quite big turbo.





Before somebody ask why 6M, not 7M crank - when I ordered stroker kit from Rich 1 year ago he had 6M crank in stock and I choose to use it. Many people consider lightened 7M crank the best since it is smoother running crank, but AFAIK running 6M in high hp motor is not detrimental for bearing life. I opted to knife edge and nitride crank.
Pistons are custom made coated 84.0mm CP, 18.5cc dish volume. I am shooting at 8.7 compression ratio with ~ 1.0mm squish



Will be using TMS main caps



I wanted to order new cylinder block last winter, dealer quoted best price something like $2400 :aigo: Decided to use old block

Will continue this this thread tomorrow, more pictures to come

 

[mk3design]

Nice, looking forward to more!

 

[Kristian_Wraae]

Nice looking parts. Subscribed!!

How does a stroked crank hold up in terms of durability? Will it last as long as the original?

 

[mk3ukr]

How does a stroked crank hold up in terms of durability? Will it last as long as the original?

I know only about 3 running stroked 7M - engines of Adjuster, figgie and one more guy, he is N/A I beleive. They all don't have problems with cranks AFAIK. Adjuster had problems, but it was manufacturing defect.
With this longer stroke and standard length connecting rod my rod to stroke ratio will be 1.543, which is quite low, but not very low. Some Honda engines have R/S ratio lower then 1.5 (this is unconfirmed info, didn't research it) I read many different opinions about advantages of longer rod engines and disadvantages of short rod. Short rod engines theoretically have higher friction losses due to higher rod angularity in cylinder liner. Cylinder bore wear can be more, but with modern oil it should not be the problem.
Short rod engines also have their own advantages, like higher average piston speed and better breathing abilities with properly matched parts
Generally longer rod engine is safer bet for longetivity, I choose stroker for faster spooling big turbo.

Now about my turbo. I have to admit I didn’t research it properly before ordering it. I decided to order 78mm compressor wheel turbo capable of magic 1000 crank hp. When Rich offered good deal on Turbonetics Y2K I couldn’t miss it. When I received this turbo 2 weeks ago I realized this is all out race unit. It got undivided turbine housing, footprint much larger then standard T4, maybe closer to T6, not sure. Turbine wheel is huge, 89mm exducer, 84 trim, 0.96 a/r housing. Even Garrett 45R has 87mm wheel, though compressor wheel of 45R is 81mm vs. my 78mm.

Y2K footprint vs. T4







Y2K is not water cooled, I asked Turbonetics tech about it, he replied that they opted to have it oil cooled only to have more space for oil jacket which helps to handle high dynamic thrust loading of bearing section.
Gas side outlet is 4.5’, requires special V-band clamp and flange which have to be welded to 5’ downpipe:icon_razz.
And this turbo is heavy, close to 20kg (nearly 45lb)

 

[integra08]

Nice looking set of parts.Waiting to see how that stroker comes out

 

[3tc power]

nice

 

[GC89]

So what are your goals with the car? The stoker kit should help but your right that is an all out race turbo and I would think it will be a bit laggy for a street car. You also didnt mention what rods you are going with?

Looking good so far though. In for updates

 

[mk3ukr]

Thanks, guys. I will try to keep this story short and hope to get this motor running in July-August.
Measured weight of 6M stroker crank today - 21.4kg (47lb) Will weigh my stock 7M crank when I take my motor apart.
Last 2 weeks I was busy rebuilding my cylinder head. I left my car in my friend's shop for fabrication of exhaust manifold, downpipe, etc. I put my spare head on motor and took my future working head to my garage for rebuild.
Found were head gasket blew - cylinders 4, 5, 6 from exhaust manifold side. When I was removing head bolts they were quite loose there.



Now I will be using ARP studs, far better then bolts.
Coating on Ferrea exhaust valves peeling off. In fact I was not aware exhaust valves are coated when valves were new 3 years ago. Now coating can be easily removed by steel or even soft brass wire brush. On some of the valves coating in more or less good condition, on worst 20-30% missing

 

[suprarich]

Vladimir - turbonetics quit making the y2k 78 a while before you ordered that turbo and they made your turbo special. It is a one off custom 78 that uses some y2k 80mm internals. All the y2k's are t-6 flange. Your turbo is better than the off the shelf 78.

suscribed for the high end 7m build of the year!

 

[mk3ukr]

So what are your goals with the car? The stoker kit should help but your right that is an all out race turbo and I would think it will be a bit laggy for a street car. You also didnt mention what rods you are going with?

Looking good so far though. In for updates

Goal is to run 10's and then hopefully 9's with GM auto. I will be trying to keep my setup as efficient as possible to have it more or less enjoyable on the street
Rods are Pauter, will be here in 2 or 3 weeks

 

[mk3ukr]

Vladimir - turbonetics quit making the y2k 78 a while before you ordered that turbo and they made your turbo special. It is a one off custom 78 that uses some y2k 80mm internals. All the y2k's are t-6 flange. Your turbo is better than the off the shelf 78.

suscribed for the high end 7m build of the year!

Rich, so, this is T6 flange? I didn't bother to search and find dimensions of T6. For some reason I thought it got non-standard footprint.
From point of view of streetability GTK 76 mm would be much better turbo, and capable of close to 1000whp

 

[suprarich]

The GTK series - I have not heard very good feedback on the GTK line. You will spool the y2k with little problem. Gary Curmi in Malta used a y2k 88 on his 7m dragster with a std stroke and had very little trouble spooling it. The y2k you will be hard to find a bad word about them. Quick spool for their size, huge shaft, and a dyno curve like few others.

 

[mk3ukr]

Back to my cylinder head.
I borrowed set of 30, 45 and 60 deg. seat cutters from my machinist friend and did standard Toyota 3-angle valve job. Everything according to TSRM, and it takes a lot of time doing it manually.







Then I prepared valve seat protectors from old standard size valves and ground off all sharp ridges in combustion chamber. There are many of them, especially after using 30deg. cutter for fitting oversize valves.



All these sharp corners have to be removed to create smooth entry/exit and eliminate turbulence when valve in low lift position



In the end it looks like this



In perfect world combustion chamber would be smooth and polished like mirror, but it's good enough for me, I spent too much time with dremel tool :biglaugh:
Finally I cc'd combustion chambers, used simple medical 20cc syringe. For me most important was to ensure equal volume of chambers, all of them measured 44.5 - 45.0cc, no.6 was 44.0cc, I removed some meat to bring it to 44.5cc

 

[GC89]

I would think it would be streetable with the stroker, I dont know if you would want to change it much with your goals on the strip. I was hoping you would say pauter with the pistons speeds your going to see.

I hear you on the head work, I'm porting my intake side right now and am not looking forward to having to do it all again on the exhaust.

 

[IJ.]

In perfect world combustion chamber would be smooth and polished like mirror, but it's good enough for me, I spent too much time with dremel tool

And in that same world 15 minutes of running would have a build up of combustion byproducts rendering the time spent polishing useless Vlad

 

[FullNelson]

Just checking, but this is going back into a mk3?

 

[mk3ukr]

I would think it would be streetable with the stroker, I dont know if you would want to change it much with your goals on the strip. I was hoping you would say pauter with the pistons speeds your going to see.

I hear you on the head work, I'm porting my intake side right now and am not looking forward to having to do it all again on the exhaust.

For amateurs like us without previous experience it quickly becomes very boring. My head was ported 3 years ago by Revolutionary Performance in States, but they didn't do anything to combustion chambers
I have already completed my head work, waiting for Cometic gasket set from Rich to arrive. Have to change valve seals and then assemble the head

 

[mk3ukr]

And in that same world 15 minutes of running would have a build up of combustion byproducts rendering the time spent polishing useless Vlad

This comment makes me feel better:icon_bigg, I felt something like sense of being guilty because chambers not polished
Ian, good to see you here, I will need your expertise. This is first time I am rebuilding engine myself.

 

[mk3ukr]

Just checking, but this is going back into a mk3?

Yes, mk3

 

[tbcmorris]

Subscribed.....definetly interested in porgress. Great start