Im thinking of fitting a set of roller rockers to my 202 type yella terra head on my 186 which has the fixed rockers and i was just wondering if it is worth having studs fitted like the 186 etc: style heads and what is involved in doing this?
Cheers Matt
Roller Rockers
Started by
superfly_GTR
, May 13 2006 07:03 PM
29 replies to this topic
#1
superfly_GTR
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Posted 13 May 2006 - 07:03 PM
#2
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Posted 13 May 2006 - 09:16 PM
A few hundred dollars in getting the head machined for screw in studs. This involves removing the head. If you get bolt on RR's for the 202, you only need to remove the rocker cover. If you're not going to rev it over 6000, take the cheap option.
#3
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Posted 14 May 2006 - 03:22 PM
I agree, studs would only be necessary in an engine you are going to work really hard.
#4
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Posted 14 May 2006 - 05:01 PM
cool thanks guys, I think im going to be running quite a hot cam if I go ahead with the rollers and a cam change and i dont know if it is worth paying the extra for adjustables or not... I have been quoted $340 for the standard and $411 for the adjustables, both are street terra rockers and are the shaft type with a shaft joining each group of 2 rockers, what do you think?
Thanks Matt
Thanks Matt
#5
_[BOTTLEDUP]_
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Posted 14 May 2006 - 06:31 PM
If you plan running anti-pump up hydraulic lifters or a solid cam then you will need the adjustable roller rockers.
As a general rule of thumb Street Terra's are good for 0.550" lift, 6500rpm and 300lb spring pressure. Any more than this and you'd be best looking at Yella Terras
As a general rule of thumb Street Terra's are good for 0.550" lift, 6500rpm and 300lb spring pressure. Any more than this and you'd be best looking at Yella Terras
#6
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Posted 14 May 2006 - 08:25 PM
i will just be running the std hyd lifters, but i was told that if it is a pretty hot cam i should still go with the adj type, is this correct or can i save some $$$ and get the std ones?
also is that a good price?
Cheers Matt
also is that a good price?
Cheers Matt
#7
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Posted 14 May 2006 - 09:42 PM
If it's only going to cost an extra $71, get the adjustable ones.
#8
_LJ308injected_
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Posted 15 May 2006 - 05:00 PM
I use to have street terra's many yrs ago and i can tell you depending on lift as they dont handle high lift, And for the extra stuff all you would be better off for the adjustable stud mount as you can always up the cam size down track and save money in the long run no point doing things twice.
regards: Steve
regards: Steve
#9
_Sammy_
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Posted 16 May 2006 - 12:52 PM
these are what i would suggest, they are the adjustable type which bolt straight onto any stock 202 head.
they are easy to adjust and reasonably priced!
#10
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Posted 16 May 2006 - 07:24 PM
They look like YT 5007's on a 186 head.
#11
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Posted 16 May 2006 - 08:12 PM
Looks like a 202 head to me. (going by the bolt holes around no. 1 spark plug)
#12
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Posted 17 May 2006 - 12:52 PM
the head is actually a brand new casting (blue/black 202) from yella terra, its a road racer head, other than ports and valves etc its the same as a stock casting.
as far as what the rocker part number is im not sure as YT's website no longer has any useful information on it.
as far as what the rocker part number is im not sure as YT's website no longer has any useful information on it.
Edited by Sammy, 17 May 2006 - 12:54 PM.
#13
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Posted 17 May 2006 - 07:02 PM
why do you need adjustables for anti pump up lifters?
#14
Dr Terry
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Posted 18 May 2006 - 11:57 AM
Hi Guys.
This is a common misconception, that the fixed type rocker gear was used because the hydraulic lifters will take up any lash. Fixed rocker gear was only used to save time on the production line. Everything is pre-calculated so that the clearances will work just right, in a new assembly.
That's fine if everything is new & to exact factory specs. But when you are building up a motor out of bits & pieces, you need to check the valve lash & adjust it if necessary. If you have fixed rocker gear, you have to grind down the posts down or shim them up. If the gear is adjustable then it's easy.
This is why you hear so many engines with noisy tappets, most of these cars have their valve lash set wrongly. An hydraulic lifter can only do so much, if it's working too close to one end of its internal travel, you will have dramas.
Think about it. If you are building up a new engine, using a different cam, lifters, head gasket, deck height & of course, the head has been fully serviced & faced, then the total lash is going to be different to how it was when it left the factory. Most guys just screw on the fixed rocker gear, which in some cases has its own wear issues, & they think it will be OK. Fact is, most of the tappets will either too far down or too loose (or a combination of both).
Even if you do a simple head service on an otherwise stock original motor, by the time the valves are ground & the head is faced, & then get the head back on the block, with a new (different) gasket, the tappet clearances will be totally different to original.
This is the main reason why most guys used to use the older style 149/161/179/186 heads with the factory adjustable rockers, when rebuilding 173s & 202s. Even Harry Firth used the adjustable (186) rocker gear, as factory standard, on the 202 XU-1, just think how many times their motors were stripped down & rebuilt.
Dr Terry.
This is a common misconception, that the fixed type rocker gear was used because the hydraulic lifters will take up any lash. Fixed rocker gear was only used to save time on the production line. Everything is pre-calculated so that the clearances will work just right, in a new assembly.
That's fine if everything is new & to exact factory specs. But when you are building up a motor out of bits & pieces, you need to check the valve lash & adjust it if necessary. If you have fixed rocker gear, you have to grind down the posts down or shim them up. If the gear is adjustable then it's easy.
This is why you hear so many engines with noisy tappets, most of these cars have their valve lash set wrongly. An hydraulic lifter can only do so much, if it's working too close to one end of its internal travel, you will have dramas.
Think about it. If you are building up a new engine, using a different cam, lifters, head gasket, deck height & of course, the head has been fully serviced & faced, then the total lash is going to be different to how it was when it left the factory. Most guys just screw on the fixed rocker gear, which in some cases has its own wear issues, & they think it will be OK. Fact is, most of the tappets will either too far down or too loose (or a combination of both).
Even if you do a simple head service on an otherwise stock original motor, by the time the valves are ground & the head is faced, & then get the head back on the block, with a new (different) gasket, the tappet clearances will be totally different to original.
This is the main reason why most guys used to use the older style 149/161/179/186 heads with the factory adjustable rockers, when rebuilding 173s & 202s. Even Harry Firth used the adjustable (186) rocker gear, as factory standard, on the 202 XU-1, just think how many times their motors were stripped down & rebuilt.
Dr Terry.
#15
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Posted 18 May 2006 - 01:20 PM
I use YT 5007 bolt on rockers on my Torrie has a 35/75 cam, looks like Sammie's photo, work fine, how ever they have only been running a year and the car is a streeter sees the very odd 6000rpm no issues as yet, had the rocker cover off a couple of time to go over the adjustment just for good measure, been perfect both times. Set on EBay brand new $300 will have posi lock adjusters.
#16
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Posted 18 May 2006 - 01:22 PM
Forgot to mention, Rocker Geometry is very important to check once the rockers are replaced you might need different length push rods.
#17
superfly_GTR
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Posted 18 May 2006 - 01:58 PM
thanks for all this good info guys, im just curious the only roller rocker talked about in this post is the YT 5007's but I was quoted prices on ST 2030's (fixed) and ST 2031's (adj) what is the differance and what is better?
I was told that the ones I was quoted on were to suit bolt on style 202 head and that each group of two rockers were joined together by a shaft so no guide plates required.
Cheers Matt
I was told that the ones I was quoted on were to suit bolt on style 202 head and that each group of two rockers were joined together by a shaft so no guide plates required.
Cheers Matt
#18
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Posted 18 May 2006 - 02:51 PM
Hi Matt.
The ST2030 are fixed & mounted in the same fashion as stock 202 lifters, i.e. in pairs & no adjustment, so there's no great advantage in fitting them.
The ST2031, to my knowledge are basically 186 style roller rockers, so they fit & adjust the same as a 186 set-up. The expense here is you will need to have the head off the car, to be machined for studs & guide-plates. The advantage is that your rocker gear is now adjustable.
The YT5007 (pictured) bolt in place of the stock 202 rocker gear, so no machining is required & you have fully adjustable rocker gear.
I would go for the YT5007.
Dr Terry.
The ST2030 are fixed & mounted in the same fashion as stock 202 lifters, i.e. in pairs & no adjustment, so there's no great advantage in fitting them.
The ST2031, to my knowledge are basically 186 style roller rockers, so they fit & adjust the same as a 186 set-up. The expense here is you will need to have the head off the car, to be machined for studs & guide-plates. The advantage is that your rocker gear is now adjustable.
The YT5007 (pictured) bolt in place of the stock 202 rocker gear, so no machining is required & you have fully adjustable rocker gear.
I would go for the YT5007.
Dr Terry.
#19
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Posted 18 May 2006 - 06:16 PM
well now im confused because I just looked at what are ment to be YT 5007's on ebay and they look to be separate rockers and non adjustable, is this the case or is the description incorrect?
Cheers Matt
Cheers Matt
#20
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Posted 18 May 2006 - 08:10 PM
Dr Terry is wrong.
The YT 5007 is for the 186 type head with studs and adjustable rockers.
The YT 5007 is for the 186 type head with studs and adjustable rockers.
#21
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Posted 19 May 2006 - 01:28 AM
so I need the ST2031's is that correct?
Thanks Matt
Thanks Matt
#22
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Posted 19 May 2006 - 10:12 AM
Hi Guys.
Sorry, CHOPPER, now I'm confused.
I was basing my usage of the YT5007 part number on YOUR comment on the rockers pictured.
The head was a 202 (i.e. no studs) & the adjustment is obviously at the pushrod end of the rocker. Aren't these the ones required, regardless of theIR part number.
Why would you need an adjustment screw on a rocker arm that adjustment available at the studs.
Dr Terry.
Sorry, CHOPPER, now I'm confused.
I was basing my usage of the YT5007 part number on YOUR comment on the rockers pictured.
The head was a 202 (i.e. no studs) & the adjustment is obviously at the pushrod end of the rocker. Aren't these the ones required, regardless of theIR part number.
Why would you need an adjustment screw on a rocker arm that adjustment available at the studs.
Dr Terry.
#23
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Posted 19 May 2006 - 12:18 PM
ok let me clear this up for everyone....
the ones in the picture i posted previously are ST2031 - Street Terra, shaft mounted bolt on ADJUSTABLE (via pushrod end of rocker).
the ST2030 is a NON adjustable version of the ST2031 - can't see any reason why you'd want this one.
the YT5007 is a Yella Terra rocker, not a street terror, its designed to be stronger, race type use, and is a 3/8 stud mounted rocker, which would slot straight onto a 186 head, but would need 202 head to have machining and fitting of 3/8 screw in studs and guide plates.
there is also street terror versions of the YT5007 which are screw in stud mounted and they are ST2007 - 3/8 and ST2008- 7/16.
if you want rockers to suit a stock 202 head, then get ST2031, if you want rockers to suit a 202 head with screw in studs or a 186 head then use ST2007 ... i doubt for any street motor you'd need the YT versions ......
the ones in the picture i posted previously are ST2031 - Street Terra, shaft mounted bolt on ADJUSTABLE (via pushrod end of rocker).
the ST2030 is a NON adjustable version of the ST2031 - can't see any reason why you'd want this one.
the YT5007 is a Yella Terra rocker, not a street terror, its designed to be stronger, race type use, and is a 3/8 stud mounted rocker, which would slot straight onto a 186 head, but would need 202 head to have machining and fitting of 3/8 screw in studs and guide plates.
there is also street terror versions of the YT5007 which are screw in stud mounted and they are ST2007 - 3/8 and ST2008- 7/16.
if you want rockers to suit a stock 202 head, then get ST2031, if you want rockers to suit a 202 head with screw in studs or a 186 head then use ST2007 ... i doubt for any street motor you'd need the YT versions ......
#24
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Posted 19 May 2006 - 10:05 PM
I think I need a coffee after reading all of this thread.
#25
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Posted 19 May 2006 - 10:22 PM
Thanks for that sammy, also are Crane rockers any good? as im looking at a second hand set on ebay which are only around $250 at the moment.
Cheers Matt
Cheers Matt
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