84DA CROSSFLOW BUILD

[CHESTNUTXE 7,310]

yeah the assembled short motor should be back next week maybe

[CHESTNUTXE 7,310]

i fitted the mounts

[Mustardxf2 310]

I'm running 10.5:1 comp with very similar size cam, just a couple thou bigger lift works great

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[CHESTNUTXE 7,310]

yeah i watched yur video ,goes hard in 1st off the line

[CHESTNUTXE 7,310]

mate what diff ratio are you running ? 

[slydog 7,873]

11.7 on 98 is fine with that cam. I run 13- 1 on 98 in mine and it's fine. I know many cry about it and say it's not possible but they also havn't done it so wouldn't know.  

I'd go flat tops 11.7 and that cam if it's still possible but more critical is that they dial the camshaft in because it "will be out". Tighe are hope less with this and if it is just installed dot to dot valves and pistons can make out at worst or terrible running no power @ best. 

Hate to be negative but dialling the camshaft in is "that" important. Having to use there cams as a base to be ground by Phill Duggan of Surecam for a suitable profile but pin placement is done @ Tighe before hand and always wrong.

[Mustardxf2 310]

mate what diff ratio are you running ? 

3.45 el diff

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[CHESTNUTXE 7,310]

3.45 to 3.9 seem very popular for the crossy

[Mustardxf2 310]

Yeah they make a big difference in the low end, although I'm thinking of going lower like 4.11

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[slydog 7,873]

4:11's 5000 convertor 3x50mm webbers over 1600kg's and still got 11mpg on Drag Challenge.

Yeah 4:11's are too much. 

[CHESTNUTXE 7,310]

I only have 3.27 atm but will take diff to shop to get rebuilt with a shorter set I was thinking 3.7 or 3.9

[CHESTNUTXE 7,310]

8 hours ago, slydog said:

11.7 on 98 is fine with that cam. I run 13- 1 on 98 in mine and it's fine. I know many cry about it and say it's not possible but they also havn't done it so wouldn't know.  

I'd go flat tops 11.7 and that cam if it's still possible but more critical is that they dial the camshaft in because it "will be out". Tighe are hope less with this and if it is just installed dot to dot valves and pistons can make out at worst or terrible running no power @ best. 

Hate to be negative but dialling the camshaft in is "that" important. Having to use there cams as a base to be ground by Phill Duggan of Surecam for a suitable profile but pin placement is done @ Tighe before hand and always wrong.

Yes the ol.m8 will dial the cam in,i also bought the fluted lifters tighe recomended,i wil give this combo a run for a while then up it to flat tops i suppose,sly are you running a very small chamber like 40cc to get to 13-1 ?

[slydog 7,873]

No you won't. Your set in the low comp now,it's in your words. Fluted lifters...ummmmm I don't know but suggest there the same as EDM with a hole on the face to lubricate the camshaft and lifter. What I did find is that it's very very very critical to get run in procedure correct or you will wreak the cam shaft on start up. Long drawn out process that not many do correctly.  

Chamber is rather open in mine hence the lack of outright flow but the head has been decked and has chambers that are resistant to hot spots and detonation.

  

Yes regardless of what the combo is they need cyl heads to work.This head is not ideal but works because Ricky Naughton of LHT Race Engines did a killer job with what he had to work with and it has shown the numbers.Can't recommend his work enough TBH.   

[Lord_fahrquhar 2,580]

So Rob

 

what do you recommend as run in for a solid roller?

 

Dave 

[slydog 7,873]

Solid roller is lean in the window hit the key. Then load it on the trailer and go race it lol.

Well thats what I did anyway

[Lord_fahrquhar 2,580]

Yeah I can run with that

[slydog 7,873]

 A mechanical flt tappet requires...rocker cover just sitting on the engine with paint dots on the pushrods to see if there spinning,engine oil pump primed with oil coming out the pushrods,I actually pre-heat the oil even,outer valve springs only,no inners or dampers to be used at this time,use a quality run in oil like Joe Gibbs which has heaps of zinc and shit in it,have a mate with you on stand by,make sure there's petrol in the carb and spark from the ignition,timing light in hand and spanner to set dizzy as soon as it starts to get timing on point,I also have a large water jug or better yet the garden hose there and running to help cool of rad or top up if needed and in case of well fire. Extinguisher on hand is good too.   

Start the engine get it up to RPM check timing,set timing,check all pushrods are turning and oil is coming out the pushrods and there's no fuel/oil leaks.Small water leaks and stuff are not a problem here.Once that all checks out bolt rocker cover down and do your rpm changes for 20mins. Soon as it's done check and gap valve lash if needed,fix what ever is loose or wrong and check oil condition? If OK take it for a drive and dont take rpm over 3000rpm. Drive it like this for about a week then give it a fresh oil change and fit the inner springs aswell.At this point you can finally start it and via your paint dots confirm your pushrods are still turning.If all good and lash is still good give it say a 500kms or till the oil changes colour and give it another oil change then it's ready for you to be a lazy non caring car owner again. And don't be scared to put some spring on em.I know you will be told too much spring is bad but so is too little and often alot of harmonic issues and broken springs come from too soft springs.PSI springs have lots of good reading and Jason Murphy did a seminar with them and was surprised how much spring they told people to use and the difference it made ti engines.

Thats how I ran if flat tappets.Expensive timley and a pain but it's what you have to do with them if you want em to last.  

    

[CHESTNUTXE 7,310]

i have a wet blanket to throw over the carb ,hose on standby,never needed any of them but good to have it there incase of fire.

[Lord_fahrquhar 2,580]

Sounds like rollers are less fuckin hassle

[CHESTNUTXE 7,310]

yes the ultimate but another grand and need some special lifters and blocks work I think

[slydog 7,873]

Not special just BBF...block needs clearanceing with a die grinder around 2 and 5 lifters.Takes around 10mins. 

The result is...a bad ass engine that idles like a baby,goe's like a mo fo and requires zero run in period and will out power a flat tappet.

 

[CHESTNUTXE 7,310]

im gunna go down the machine shop thismorn and see how its coming along,i want to paint the block b4 he starts to assemble the bottom end.

[CHESTNUTXE 7,310]

playing around with the rocker gear ,i watched a video last night from summit ,how to get the right length pushrods,i have std and 9.5 just for a look ,but will borrow ol.m8's adj pushrod to find the correct length,he seems a bit worried i might stuff it because there is no checking springs installed on the head,so i must be careful,maybe i should just buy 1,its been on my list of things to buy for a while,but speed shops are asking 5 times the price as a usa shop ?

[CHESTNUTXE 7,310]

clowning around im getting itchy to do something,

[CHESTNUTXE 7,310]

is the alt/air bracket all the same on crossy's or does the non air have a different bracket as this one is heavy as hell ?