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202 Engine build

Started by _rich243_ , May 31 2015 09:58 AM

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#1 _rich243_

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Posted 31 May 2015 - 09:58 AM

Im in the very early stages of planning an engine build project and collecting some parts. My goal is to build a hot 202 for my LJ, nudging as close to 300hp as possible and im looking for advice and tips from anyone who is keen to point me in the right direction. Pretty keen to do as much as possible myself, having a mechanical/maintenance engineer background and generally just like to tinker and see how, what works and why. But also understand that many people have been there done that and I'm happy to pick up a head already done to achieve what i need for example.

Have read johnno's how to build a holden 6 page plus numerous threads here, great reading.

Have quite a bit of experince building small engines, ie 4 and 2 stroke motorbike engines, but very limited experience with building 202's etc.

I have a good cast 202 red that was recently bored 0.60" i could use. But seems the blue/black virgin block could be a better starting point?

Am pretty keen to stick with the old 9 port as i prefer the old school original if i can. Would i be better of say starting with a 2nd hand yella terra stage 3 here as good starting point for the head if i can pick one up for decent $ or does it not really matter in the scheme of things and just get a bare stock 9 port?

And keen to stick with NA and go with triple webbers, just love that sound.

This is a long term build project so plenty of time to collect bits and build as i can.

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#2 _Muzzy_

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Posted 31 May 2015 - 01:30 PM

Well covered in many threads, old Johno engine building web site is the best for a great source of info and covers many little mistakes that can be made along the way
If you need a small chamber "H " head I have one you can have dirt cheap that is stock , on a 202 this will start at about 10.5:1

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#3 _STRAIGHTLINEMICK_

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Posted 31 May 2015 - 02:02 PM

Im in the very early stages of planning an engine build project and collecting some parts. My goal is to build a hot 202 for my LJ, nudging as close to 300hp as possible and im looking for advice and tips from anyone who is keen to point me in the right direction. Pretty keen to do as much as possible myself, having a mechanical/maintenance engineer background and generally just like to tinker and see how, what works and why. But also understand that many people have been there done that and I'm happy to pick up a head already done to achieve what i need for example.

Have read johnno's how to build a holden 6 page plus numerous threads here, great reading.

Have quite a bit of experince building small engines, ie 4 and 2 stroke motorbike engines, but very limited experience with building 202's etc.

I have a good cast 202 red that was recently bored 0.60" i could use. But seems the blue/black virgin block could be a better starting point?

Am pretty keen to stick with the old 9 port as i prefer the old school original if i can. Would i be better of say starting with a 2nd hand yella terra stage 3 here as good starting point for the head if i can pick one up for decent $ or does it not really matter in the scheme of things and just get a bare stock 9 port?

And keen to stick with NA and go with triple webbers, just love that sound.

This is a long term build project so plenty of time to collect bits and build as i can.

G'day Brian ,

My first recommendation is to start with a proven combination that includes the parts you have mentioned . If you aim for 300hp you will end up with a very peaky engine that wont have much torque and be cranky below 4500-5000 rpm and the diff ratio will need to be 3.9 to keep it on the boil ..If this is what you want then it is achievable ,If you aim for 270-280hp (enough for low 13sec 1/4 in an LJ ) then you will have much better torque ,drivability and rpm's can stay below 6500 for reliability .

Dony worry about the yella terra ,just find a 173 small chamber head (i have one ) and send it to a good head porter to get it to flow around 280-300hp at around .500" lift with the exhaust about 70-80 % of intake flow .Valves need to be able to lift about .550" before binding .

Next is the bottom end , you can build a stock rodded 202 and get a good result but a much better result will be achieved with a long rod stroker which we can supply .This will produce a little more power and a lot more torque where you need it .

Next step is yours to set your budget and see what can be done for that budget .Mick

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#4 _Bomber Watson_

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Posted 31 May 2015 - 04:20 PM

All of the blue blocks I have are core shifted massively towards the cam shaft.....not the side you want it on.

Run a thickness tester over the +.060" you already have and see what its like. Not all blocks are equal I have a +.040" red block here that has more material on the thrust side (welch plug side) than some of the Virgin blues have.

For my new head the porting lad requested a yt head to start with so that's what he got. There pretty hard to find in small chamber guise though, most of the small chamber heads that crossed yt's bench had the chambers milled out making them useless to us.

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#5 _Agent 34_

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Posted 31 May 2015 - 04:45 PM

Bomber - where do you get the wall thickness tested ?

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#6 _Bomber Watson_

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Posted 31 May 2015 - 04:49 PM

Brought a cheap thickness tester off ebay.

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#7 _STRAIGHTLINEMICK_

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Posted 31 May 2015 - 04:55 PM

All of the blue blocks I have are core shifted massively towards the cam shaft.....not the side you want it on.

Run a thickness tester over the +.060" you already have and see what its like. Not all blocks are equal I have a +.040" red block here that has more material on the thrust side (welch plug side) than some of the Virgin blues have.

For my new head the porting lad requested a yt head to start with so that's what he got. There pretty hard to find in small chamber guise though, most of the small chamber heads that crossed yt's bench had the chambers milled out making them useless to us.

Hey bomber and others, lets bounce some ideas around. .... What if you were to take advantage of the coreshift and offset bore the block to reduce valve shrouding. (this topic might need a new thread )

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#8 _STRAIGHTLINEMICK_

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Posted 31 May 2015 - 04:58 PM

Bomber - where do you get the wall thickness tested ?

I got mine sonic tested for wall thickness by Dominator at Guildford .

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#9 _Bomber Watson_

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Posted 31 May 2015 - 05:21 PM

Pretty well all of the blue blocks I have would have to be offset bored for any kind of high performance application.

I'm not totally convinced the .040" or so you would move the cylinder towards the cam would help with unshrouding terribly much, but I doubt it would hurt either.

Definitely something to consider. Close attention would have to be payed to the wall thickness at 1 and 11 o'clock if you imagine the camshaft side of the bore is 12 o'clock.

Definitely a discussion for another thread.

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#10 _Agent 34_

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Posted 31 May 2015 - 06:48 PM

there's no two ways about a longer rod length to ease the sideways affect on a std motor.

So are you saying that an " off bored block " will also handle a bit more or assist in the sidewards motion ?

would you need a virgin bore so that the top could be " offset and the bottom offset as well " in order to get 60 thou ?- in different directions ( opposite axis)

were bloody splitting hairs

Edited by Agent 34, 31 May 2015 - 06:49 PM.

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#11 _STRAIGHTLINEMICK_

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Posted 31 May 2015 - 07:50 PM

there's no two ways about a longer rod length to ease the sideways affect on a std motor.

So are you saying that an " off bored block " will also handle a bit more or assist in the sidewards motion ?

would you need a virgin bore so that the top could be " offset and the bottom offset as well " in order to get 60 thou ?- in different directions ( opposite axis)

were bloody splitting hairs

Yep we are splitting hairs , What i mean is say the casting has core shift and is thicker towards the cam side then you could move the bore centers to the cam side about .040" to get the bore in the centre of the casting and also help unshroud the valves,every bit helps because about 1/3 of the intake valve is shrouded by the bore ..Anyway we shouldnt hijack his thread to discuss this issue.

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#12 _duggan208_

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Posted 31 May 2015 - 11:44 PM

I suppose that if you offset bored the block you could sleve the block to support the thinnest part of the bore.

You are going to need a very good head for 300 HP. It seems that the 9 port, closed chamber is the one to go for. Probadly does not make much difference if you start with a yella terra. You will still need to do alot to it for your 300HP. If you use a 9 port consider looking at those Mikuni carbs. Even though Webers will work for the 300 HP target, they may not quiet suit the siemeised ports of the 9 port as well as SU's or Mikunies. As mick said it will be a cranky bugger, kinda fun though.

regards

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#13 warrenm

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Posted 01 June 2015 - 07:05 AM

As Mick & duggan208 has already mentioned, to make the 300hp mark, the engine will be on the cranky side, my advise would be to aim a bit lower 270/280 area.

This is what I would do, hang onto the 202 .060" block & keep it for another project, unless it has plenty of wall thickness. I prefer to use a blue/black block as a starting point,(they have a few less years corrosion) preferably something that hasn't bored, that way you can keep the oversize to .030" or .040". A 9 port, small chamber head with some port work (like a yt)will make your hp. The blue/black motor will also have the rods & counterweight crank, unless you are going to use after market rods std rods or longer rods which all come at a cost. As for a cam, you"ll need something with a duration around the 240°/250° area, but talk to a cam grinder to come up with the correct cam for your needs & combo.

Mick, I don't think that offset boring the block will unshroud the valve enough, unless you can shift it atleast .100".

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#14 _rich243_

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Posted 01 June 2015 - 09:39 AM

Thanks for the replies all, feel free to talk about whatever you like here

Well covered in many threads, old Johno engine building web site is the best for a great source of info and covers many little mistakes that can be made along the way
If you need a small chamber "H " head I have one you can have dirt cheap that is stock , on a 202 this will start at about 10.5:1

I may well take you up on that offer muzzy, sounds like a good starting point, will send you a message.

G'day Brian ,

My first recommendation is to start with a proven combination that includes the parts you have mentioned . If you aim for 300hp you will end up with a very peaky engine that wont have much torque and be cranky below 4500-5000 rpm and the diff ratio will need to be 3.9 to keep it on the boil ..If this is what you want then it is achievable ,If you aim for 270-280hp (enough for low 13sec 1/4 in an LJ ) then you will have much better torque ,drivability and rpm's can stay below 6500 for reliability .

Dony worry about the yella terra ,just find a 173 small chamber head (i have one ) and send it to a good head porter to get it to flow around 280-300hp at around .500" lift with the exhaust about 70-80 % of intake flow .Valves need to be able to lift about .550" before binding .

Next is the bottom end , you can build a stock rodded 202 and get a good result but a much better result will be achieved with a long rod stroker which we can supply .This will produce a little more power and a lot more torque where you need it .

Next step is yours to set your budget and see what can be done for that budget .Mick

Thanks for the reply MIck. To be honest cranky and reliability arent too much of a concern for me. It wont be driven terribly often, only the occasional power cruise, tought street very occasional strip kind of thing. Just want something to give the v8 boys something to think about. I would actually prefer something that revs hard and freely, one of my past cars was a R32 GTR rice burner, that thing did nothing till about 4k then pulled like a train to 8500 rpm so easily and freely, it just felt like it wanted to rev, so smooth. I realise we are talking about 2 totally different engines here and a few years difference in technology

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#15 _rich243_

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Posted 01 June 2015 - 09:48 AM

I suppose that if you offset bored the block you could sleve the block to support the thinnest part of the bore.

You are going to need a very good head for 300 HP. It seems that the 9 port, closed chamber is the one to go for. Probadly does not make much difference if you start with a yella terra. You will still need to do alot to it for your 300HP. If you use a 9 port consider looking at those Mikuni carbs. Even though Webers will work for the 300 HP target, they may not quiet suit the siemeised ports of the 9 port as well as SU's or Mikunies. As mick said it will be a cranky bugger, kinda fun though.

regards

Havent seen much info around on the mikuni's? I guess the sound of the webbers is what gets me the most, seems blokes on here are getting very good results with SU's too.

As Mick & duggan208 has already mentioned, to make the 300hp mark, the engine will be on the cranky side, my advise would be to aim a bit lower 270/280 area.

This is what I would do, hang onto the 202 .060" block & keep it for another project, unless it has plenty of wall thickness. I prefer to use a blue/black block as a starting point,(they have a few less years corrosion) preferably something that hasn't bored, that way you can keep the oversize to .030" or .040". A 9 port, small chamber head with some port work (like a yt)will make your hp. The blue/black motor will also have the rods & counterweight crank, unless you are going to use after market rods std rods or longer rods which all come at a cost. As for a cam, you"ll need something with a duration around the 240°/250° area, but talk to a cam grinder to come up with the correct cam for your needs & combo.

Mick, I don't think that offset boring the block will unshroud the valve enough, unless you can shift it atleast .100".

Would like to go std rods/crank if possible, from the reading ive done on here it seems the counterweighted blue crank is the prefered choice for a nicer balanced combo, but red crank still used by some with no problems. Are the blue rods up to the task or am i better of going the starfire or aftermarket route? Starfire seem to look very similar to blue rods.

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#16 _Bomber Watson_

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Posted 01 June 2015 - 09:51 AM

Starfire and blue/black are the same rod.

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#17 _rich243_

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Posted 01 June 2015 - 10:02 AM

All of the blue blocks I have are core shifted massively towards the cam shaft.....not the side you want it on.

Run a thickness tester over the +.060" you already have and see what its like. Not all blocks are equal I have a +.040" red block here that has more material on the thrust side (welch plug side) than some of the Virgin blues have.

For my new head the porting lad requested a yt head to start with so that's what he got. There pretty hard to find in small chamber guise though, most of the small chamber heads that crossed yt's bench had the chambers milled out making them useless to us.

Bomber does this look like a small chamber? Apparently its a YT stage 3. Valves measure ex 1.440 in 1.680"

Chamber pic.jpg 164.26K 10 downloads

Edited by rich243, 01 June 2015 - 10:02 AM.

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#18 _Bomber Watson_

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Posted 01 June 2015 - 10:31 AM

Yeah that's the type you want. Pick of the inlet will tell more, there a pretty good base to work with according to kevvy.

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#19 _Bomber Watson_

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Posted 01 June 2015 - 10:33 AM

For a bot better understanding of what were talking about with heads see here.

http://www.gmh-toran...inder-head-101/

Cheers.

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#20 _rich243_

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Posted 01 June 2015 - 11:18 AM

Yeah that's the type you want. Pick of the inlet will tell more, there a pretty good base to work with according to kevvy.

This help?

chamber pic 2.jpg 129.76K 5 downloads

Port pic.jpg 161.5K 6 downloads

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#21 _Bomber Watson_

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Posted 01 June 2015 - 11:27 AM

Yep yt stage 3 or similar with kidney chamber intact.

Not enough picks to tell you which generation it is, but probably a good starting point. Another 2k or so on it and you will be near your 300....on the flowbrnch atleast.

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#22 warrenm

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Posted 01 June 2015 - 12:50 PM

As bomber has already mentioned, starfire/blue/black same,same. Counterweight blue crank, blue rods, blue block, 9 port head, 2" SU's & a 260° cam is what I'm running & it's making around 300 some where, not confirmed on a dyno yet, but runs 12.16@109 in a 2700lb LJ. That head looks like a good starting point, still plenty of meat left in the bowl to play with.

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#23 Uncle Chop Chop

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Posted 01 June 2015 - 03:25 PM

Havent seen much info around on the mikuni's? I guess the sound of the webbers is what gets me the most, seems blokes on here are getting very good results with SU's too.

If sound is important, install a good stereo.

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#24 _STRAIGHTLINEMICK_

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Posted 01 June 2015 - 05:17 PM

That didnt take long ,looks like youve got a combo . You should be able to build it for about 5k + carbs exhaust and ignition.By the way for ignition a modified blue motor Bosch dizzy and coil will light your fires.

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#25 _rich243_

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Posted 01 June 2015 - 06:50 PM

If sound is important, install a good stereo.

Already has doof doof fitted. Maybe i can play a sound track from a drag car when im driving

That didnt take long ,looks like youve got a combo . You should be able to build it for about 5k + carbs exhaust and ignition.By the way for ignition a modified blue motor Bosch dizzy and coil will light your fires.

Thanks Mick, No def havent decided on a combo but it does seem to be a tried and proven one. Still not sure on which way to go with the head yet. Are the valves big enough in that YT head for the approx target hp? Prob no point in spending say 500 on that when the valves are no good anyway and im sure springs etc should be changed anyway v's spending the coin on a cheaper head, starting from scratch and going new valves, springs... Is the money spent on better head bolt posts and port work on that head worth it you think?