Need advice on msd on worked 250 + carb sizing

[gerg 10,871]

You'll probably find that they actually are 1.73 but they just don't bother with the 3 on the end. If they're a positive stop, and designed to bolt-on to a stock Clevo then they'll go on your crossy.

[ando76 4,354]

Gd decision Trent.  There are some very good rockers out there and if you are going to stay under .600" lift you can even use cast ones.  I know plenty will disagree with me there but I have used stocko bolt on Yella terra cast roller rockers (street terra) on a speedway motor that lifted to .583" without an issue - probably because of the correct valve springs (ISKY).  This motor gets pinged from 4500-6500 time and time again.

 

Don't get me wrong I love my billet items as well - mainly because they look so good when you are doing your rocker checks - but really once the tappet cover goes on, who cares - as long as they work.

 

Crane are a good brand so if you have the coin and they are direct bolt on then go for it.  If they are stud mount you will have to get your head machined to suit. 

[slydog 7,873]

Start a build thread with pics of the car Trent and ideas and what you want...people can help better when there's a car to look @ on some things you don't notice.

[Trent250 21]

Gd decision Trent.  There are some very good rockers out there and if you are going to stay under .600" lift you can even use cast ones.  I know plenty will disagree with me there but I have used stocko bolt on Yella terra cast roller rockers (street terra) on a speedway motor that lifted to .583" without an issue - probably because of the correct valve springs (ISKY).  This motor gets pinged from 4500-6500 time and time again.

 

Don't get me wrong I love my billet items as well - mainly because they look so good when you are doing your rocker checks - but really once the tappet cover goes on, who cares - as long as they work.

 

Crane are a good brand so if you have the coin and they are direct bolt on then go for it.  If they are stud mount you will have to get your head machined to suit.

 

 

Why would I need to get the head machined? For rocker cover clearance?

Start a build thread with pics of the car Trent and ideas and what you want...people can help better when there's a car to look @ on some things you don't notice.

Ok I'll start one soon...

[ando76 4,354]

The stud mount use a bigger (7/16th) 'stud' not the little bolt like the bolt on's.  Therefore you have to machine the rocker posts to suit the bigger stud mounting and then tap the thread out to suit the stud. 

 

It is seen as good insurance on some hypo engines but imho if you stay below .600" lift and use the correct valve springs - bolt on adjustable are fine.  Use shit valve springs with a big lift cam and give it a hard time and you will break the smaller bolt for sure.

 

I'm only using stud mounts on my roller engine because I bought a head that had them for next to nothing.  Only reason I'm using them - not because I need to with the roller, because the valve springs suit the lift of cam and don't harmonic.

 

So by now you should be getting my little rant - correct valve springs equals happy engine and bolt on compatible.

[wagoon 2,429]

Couple of links for you to check out

This set will fit a crossflow (12 only for 6 cylinder) and are 5/16 which are bolt on http://www.scorpioncheckout.com/category_s/206.htm

This is yella terra 7/16 stud mount and as Ando said will require machining of the head http://store.yellaterra.com.au/ford-v6-yella-terra-platinum-7-16-rockers-ratio-1-73-yt6345/

This link show yella terra range for crossflow  http://store.yellaterra.com.au/categories/roller-rocker-sets/ford/ford-6-inline/ford-inline-6-australian/ford-inline-6-crossflow-1976-1993.html?sort=priceasc

 

 

[slydog 7,873]

 This motor gets pinged from 4500-6500 time and time again.

 

[ando76 4,354]

Funny thing is Fletchers XF sees A LOT LESS revs than 7000rpm.  Is it a race engine?  Oh yeah - Fastest lap time at the Kings Royal - Pole sitter and eventual King for 2015.  There were plenty of RACE engines behind him being pinned to well over 7000rpm.

 

Horses for courses my friend.  If I only had to pin an engine for 11 -12 seconds at a time I would sit it around 7000 happily.  Try getting an I6 engine to do that for 40 laps at a time at 17 seconds each and you are asking for a very expensive mess. 

 

Yes I bit hard - LOL. 

 

Now back to your regular programming.

[slydog 7,873]

Blar blar blar blar... hooked him

 

Just because 7500RPM xflows sound soooooooooooo good 

 

 

P.S and with locked timing LOL

[Trent250 21]

The stud mount use a bigger (7/16th) 'stud' not the little bolt like the bolt on's.  Therefore you have to machine the rocker posts to suit the bigger stud mounting and then tap the thread out to suit the stud. 

 

It is seen as good insurance on some hypo engines but imho if you stay below .600" lift and use the correct valve springs - bolt on adjustable are fine.  Use shit valve springs with a big lift cam and give it a hard time and you will break the smaller bolt for sure.

 

I'm only using stud mounts on my roller engine because I bought a head that had them for next to nothing.  Only reason I'm using them - not because I need to with the roller, because the valve springs suit the lift of cam and don't harmonic.

 

So by now you should be getting my little rant - correct valve springs equals happy engine and bolt on compatible.

So would these bolt straight on? I'll be under .600" for sure

http://www.ebay.com.au/itm/400839949239?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

 

Couple of links for you to check out

This set will fit a crossflow (12 only for 6 cylinder) and are 5/16 which are bolt on http://www.scorpioncheckout.com/category_s/206.htm

This is yella terra 7/16 stud mount and as Ando said will require machining of the head http://store.yellaterra.com.au/ford-v6-yella-terra-platinum-7-16-rockers-ratio-1-73-yt6345/

This link show yella terra range for crossflow  http://store.yellaterra.com.au/categories/roller-rocker-sets/ford/ford-6-inline/ford-inline-6-australian/ford-inline-6-crossflow-1976-1993.html?sort=priceasc

Those scorpion ones look good for the price... They bolt straight on?

 

Cheers everyone for the help.. It's pricless.. Thanks

[ando76 4,354]

The scorpions will bolt straight on but they are non adjustable - suitable for hydraulic cam application only.

 

The Crane ones look good but I'm not sure on the 'bolt on' claim as they look like 7/16 studs to me and they seem a little pricey.

 

If it were me I would be searching gumtree for a second hand set.  They come up from time to time and they are not the sort of thing that wears out.  They mainly get damaged if there is an engine failure.  I picked up a set of street terra for $80 locally last year - they are out there - you just have to search. 

 

If you are dead set keen on new ones then I would just buy a set from Yella Terra and support an Aussie company in the process.  The decision is yours. 

[ando76 4,354]

Blar blar blar blar... hooked him

 

Just because 7500RPM xflows sound soooooooooooo good 

 

 

 

P.S and with locked timing LOL

and then it BROKE - AGAIN........  

[slydog 7,873]

Yep the POS QLD Tighe camshaft couldnt handle it and gave up. Soft as most things that way are

[ando76 4,354]

Yeah we like our crossflows soft - 11.04, 11.4 and 11.6 or so I think... 

[slydog 7,873]

Pft Mossy came from NSW...He is a Westy infact. Only good thing to come out of QLD is GN's...that xxxx is terrible shit.  

[Trent250 21]

The scorpions will bolt straight on but they are non adjustable - suitable for hydraulic cam application only.

 

The Crane ones look good but I'm not sure on the 'bolt on' claim as they look like 7/16 studs to me and they seem a little pricey.

 

If it were me I would be searching gumtree for a second hand set. They come up from time to time and they are not the sort of thing that wears out. They mainly get damaged if there is an engine failure. I picked up a set of street terra for $80 locally last year - they are out there - you just have to search.

 

If you are dead set keen on new ones then I would just buy a set from Yella Terra and support an Aussie company in the process. The decision is yours.

 

I don't need adjustable as sticking with hydraulic cam...

Can anyone put up a link of some cheap but good ones, non adjustable..

So what do I look for with the bolt size? If they are 7/16 do I need to get the head machined..

Thanks again.....

Could go 2nd hand but I'll have to find some..aha

[Trent250 21]

Will these bolt on?

http://www.ebay.com.au/itm/CRANE-ENERGISER-ROLLER-ROCKERS-FORD-WINDSOR-CR44746-16-/180640978561?pt=AU_Car_Parts_Accessories&hash=item2a0f0a9681

 

http://www.ebay.com.au/itm/Ford-Racing-302-351-Windsor-Pedestal-Mount-Roller-Rockers-1-7-5-16-M-6564-A50-/281568108187?pt=AU_Car_Parts_Accessories&hash=item418ec45e9b

 

Just a few I found from a quick search..

I want to spend around the 400$$ mark..

[wagoon 2,429]

Someone will confirm but you will need rockers to suit cleveland not windsor. Yes 5/16 is what you want if you want bolt on. Yes 7/16 will require extra money spent on getting the head machined to suit larger stud size.

The link to the scorpion rockers I provided if a 6 cylinder engine so you only get as many as you need not the extras for a v8. Search this site for scorpion rockers as I posted an email that was sent to me by scorpion regarding fitment. If you buy the 6 cylinder scorpion from summit racing it should be on your door step for less than $300 aussie dollars. Then again you could find a set of used yella terra for the about the same price or pay double for a new set.

[Trent250 21]

Someone will confirm but you will need rockers to suit cleveland not windsor. Yes 5/16 is what you want if you want bolt on. Yes 7/16 will require extra money spent on getting the head machined to suit larger stud size.

The link to the scorpion rockers I provided if a 6 cylinder engine so you only get as many as you need not the extras for a v8. Search this site for scorpion rockers as I posted an email that was sent to me by scorpion regarding fitment. If you buy the 6 cylinder scorpion from summit racing it should be on your door step for less than $300 aussie dollars. Then again you could find a set of used yella terra for the about the same price or pay double for a new set.

I went on summit racing and there about 290 for them scorpion ones but 60$ posted to Australia.. So thinking of buying the 6al2 programmable msd box and blaster 2 coil at the same time and postage is $80 for all of it..

So them scorpions will bolt straight on.. That's what I'm after...

[Trent250 21]

Start a build thread with pics of the car Trent and ideas and what you want...people can help better when there's a car to look @ on some things you don't notice.

Just did, take a look...

[wagoon 2,429]

Didnt really notice how far the dollar had dropped. Yeah had a look at summit and its $340 aussie dollars delivered to your door. Should be able to find a used set locally for less than that especially if the dollar keeps dropping the price will continue to go up

 

Edit: here you go, yes it's in WA but post should be that much and he wants $100 for the rockers and a spacer http://www.gumtree.com.au/s-ad/byford/engine-engine-parts-transmission/250-crossflow-/1067033336

[Trent250 21]

Didnt really notice how far the dollar had dropped. Yeah had a look at summit and its $340 aussie dollars delivered to your door. Should be able to find a used set locally for less than that especially if the dollar keeps dropping the price will continue to go up

 

Edit: here you go, yes it's in WA but post should be that much and he wants $100 for the rockers and a spacer http://www.gumtree.com.au/s-ad/byford/engine-engine-parts-transmission/250-crossflow-/1067033336

 

I've looked at them ones a while ago but he won't post...

I'll buy them scorpion ones I reckon ..

[Trent250 21]

I just brought the scorpion roller rockers, msd 6al2 programable and coil to suit..

Next is a 600 mechanical holley..

Where can I get one from, they seem a bit hard to find as most are vac secondaries..

Thanks

[gerg 10,871]

Going mechanical secondaries

... got a mate that works at a petrol station huh?

 

Is there a particular reason why you need one of them? Just wouldn't want you to get it and be bitterly disappointed trying to get it right without pouring fuel down it.

 

Holley makes vac and mech carbies very different from each other for a good reason. Mech is for racing, vac is for street. The assumption with mechanical carbies is that you wont be cruising or idling much. Their emphasis is on absolute performance, and run big jets accordingly. Now here's the clincher.... You go and jet down because it's a fat pig and guess what? It falls on its face (goes lean) It's because they run small power valve channel restrictors, along with big jets. You can drill the PVCRs out and jet down but that's even more work. A mechanical carby can be made to work on the street on a (relatively) small engine like many have on here but there's the thing... Why not just get the right one?

 

Vac sec carbies are jetted pretty well out of the box for cruising and have a bigger enrichment circuit (PVCR) for when you stomp it. Also the secondaries (if set up right) only open if (and as far as) they need to.

 

Again, not knocking your suggestion if you know it will be what you want but you just want to be 100% on what to expect from a race carby vs a street one.

[Trent250 21]

Going mechanical secondaries... got a mate that works at a petrol station huh?Is there a particular reason why you need one of them? Just wouldn't want you to get it and be bitterly disappointed trying to get it right without pouring fuel down it.Holley makes vac and mech carbies very different from each other for a good reason. Mech is for racing, vac is for street. The assumption with mechanical carbies is that you wont be cruising or idling much. Their emphasis is on absolute performance, and run big jets accordingly. Now here's the clincher.... You go and jet down because it's a fat pig and guess what? It falls on its face (goes lean) It's because they run small power valve channel restrictors, along with big jets. You can drill the PVCRs out and jet down but that's even more work. A mechanical carby can be made to work on the street on a (relatively) small engine like many have on here but there's the thing... Why not just get the right one?Vac sec carbies are jetted pretty well out of the box for cruising and have a bigger enrichment circuit (PVCR) for when you stomp it. Also the secondaries (if set up right) only open if (and as far as) they need to.Again, not knocking your suggestion if you know it will be what you want but you just want to be 100% on what to expect from a race carby vs a street one.

Sounds like I'll go vac then... Much harder to fit?