Bomberman's Rb26debt Build From Dmms Or Better Known As Dazmo

[AtomicBomberMan]

HAHAH Merli! NOW you're talkin! I like where youre headed but i sorta had something in mind already. Something like this perhaps?

Always had a soft spot for MFG.... Mud Flap Girl.......

or perhaps this?

[AtomicBomberMan]

I think my white 32 can be added to the list currently getting built in bris.

Atomicbomberman, mind if i post a pic of the tomei 2.8L crank I am using? Seeing as there's a nice collection of crank pics already.

From what I can see there so far, very nice build!!

SURE NICK! Please do! Please tell us a little bit about it too!

[Beer Baron]

Wow beer barron! look at those welds! Very nice! I had a trust sump also. but sold it for the very reasons you mentioned. The baffling could be better as you say. Im sure it works though. otherwise they wouldnt have sold so many units!

Richard, I really dont mind your pics in my post! And that goes for everyone! As long as the pics are relevant PLEASE SHARE! I love to hear your ideas and to see what you guys are using! Pics tell a 1000 words so please TELL TELL TELL!

no prob. yeah the guys there did an amazing job on cutting and welding the sump. in fact they did great work on all aspects of this build and 2 others for me. I don't regret getting the work done in japan one bit. plus travelling over there I got to see a lot of the work in progress. well whilst we are on head porting I'll add a few pics of mine for comparison. I do think yours looks excellent by the way. head porting is one area though that looks don't really tell you anything, you just need to try it and see. scary!

luckily for me Tetsu has been porting RB26 heads for street, drag, circuit for nearly 20 years! he's literally done hundreds so he's learnt a lot through trial and error and he knows what works. he also built yoshioka's D1 AE86 engine which he had custom billet forged crank made for it (only 5 made), it makes something like 350ps, NA! with NOS and big revs. and it lasts.

here are some pics of it. sorry some are not very good, I didn't take all of them

note most of them are progress pics as I wasn't there to capture the finished product, but I have some of them finished, just not very good.

here is a pic of the crank I mentioned too since we are on cranks. have a look at the difference between his custom crank and an HKS crank. he said the HKS ones is rubbish! lol, most people would kill to have it. I believe his engine revs to some astronomical rev limit well north of 10,000rpm.

While we are talking heads, what did you do regarding squish/quench zones? and why? there are lots of different theories on this, it's probably the most debated part of RB26 head porting...

[AtomicBomberMan]

Awesome pics Richard! I had seen those pics before in your other thread. Very nice. The Japanese really know what theyre doing dont they! The pics of the headjob were very early in the port stage. Still quite a bit to go yet. I got a few more pics closer to the finished product. I'll put these up soon. Regarding the squish zones, I had these removed too. In your picture of the exhaust port before porting, I notice your headjob guy has drawn a mark of where the gasket finishes. There's quite a lot of material to remove. And that squish zone is all well within where the gasket finishes. This is probably why most of the headjob people remove it. I actually dont know what part the squish zone plays in the whole scheme of things. Having said that, all the big power heads that i have seen, none of them seem to retain that bump. I know that the actual finish of the port can have an effect on how the gasses move around. I have heard a coarser finish will aid better flow. Mine, i think, is a little on the smooth side. Once again, I think i'm splitting hairs.

Edited June 4, 2009 by AtomicBomberMan

[Beer Baron]

yeah, the pics I took were before he started on the exhaust side but as you said you can see where he's scribed the line for what's going to be removed. I was surprised too at just how much material is removed on the exhaust ports. you can see a pic of one finished or near finished near the bottom of the pics. the lump is completely gone.

most guys I know who have tried and tested various porting jobs and have results to back it up tell me that they subscribe to a rough guide which is.

street car/mild tuned car, leave squish/quench alone (the trade off cannot be capitalised on in a mild-ish set-up)

street/track car or mid-tuned track car, remove squish zone on one side (this enables more timing and boost without detonation and the small trade off of low down response is not felt on the track)

full on circuit/hard tuned/drag - remove squish completely. there is no noticeable problem with low down power and they can safely run more boost and timing for big powa.

this is hotly debated though. sydneykid for one says it's BS.

[Beer Baron]

oh, and my own experience. I've now had 4 heads done at prime garage. first one had squish zone left on both side and it went into the grey 32 that I sold last year. the next 2 heads had squish removed on one side and one went to a friend for his car, and one is going into my current 32. the fourth my mate mark has in his silver 32 and it was a street car with N1 turbos so it had squish left too.

[AtomicBomberMan]

hmmm, interesting. what do you mean by remove squish on one side?

[Beer Baron]

hmmm, interesting. what do you mean by remove squish on one side?

this will explain it nicely.

[AtomicBomberMan]

Oh sorry! I was watching a completely different channel! I thought you meant the bump in the exhaust port! duhhhh.... sorry mate. Yes, i left this alone. I notice a lot of the Japanese seem to have this removed. I'm not educated enough on this to really make a comment....................... DAZ! HELP!

So Richard, with the heads that went onto your cars. What tangible effects can you comment on?

Edited June 4, 2009 by AtomicBomberMan

[Beer Baron]

well it's hard to say as I never drove the same set-up minus the head. all I can say is the ones I've used so far I loved. the one about to go in will be the test. hopefully it will be good. opinion is split pretty evenly on the combustion chamber shape, some argue that removing those pads is an old school approach and takes more than it gives, but tetsu has tried all ways and does what he says works. so I was inclined to trust his advice and go with it. I don't know that there is much in it either way.

[AtomicBomberMan]

Ok, while the head was away getting ported, i needed to organise the parts to go into it. The first purchase i made was the camshafts and springs. At the time, i was a pretty big fan of the apexi stuff. This is going a while back now. Back before they went under and were still making some great parts other than air filters. The Mines 34GTR has always been a favourite of mine. A perfect combination of street and circuit. I think this would be a good role model for my car. I know i could never replicate what Mines have done, but at least i feel it paints a good picture as to which direction to head in. The Mines car is probably one of if not the main reasons why i stayed 2600cc. The Mines car ran fairly small bumpsticks with mild duration and moderate lift. I had at one stage a set of VMAX cams which were 260 degree and 11.35mm lift! These were too wild for my setup. These cams were more suited for drag racing. In the end i settled for the Apexi GT camshafts. These cams were made by Apexi with apexi cast into the side of the cam. At that time, it was a fairly big thing. A few companies then were using Nissan blanks that were ground to their specs. Im pretty sure JUN and Tomei still do. You'll find N2 cast at the end of the JUN and Tomei cams. Things may have changed since then though. The GT spec cams use a standard base circle, so different buckets were not required.

INTAKE 260 DEGREE 10.3MM LIFT / EXHAUST 264 DEGREE 10.6MM LIFT

I bought the Apexi GT Valve springs too. But later sold these for SUPERTECH DUAL VALVE SPRINGS. The Supertech stuff is Really nice. The Tomei typeC's are way too overpriced in my books. Gotta draw the line somewhere. Hopefully this will allow for higher revs.

Supertech Titanium Retainers. Once again, the Japanese JUN equivalents were priced out of reach!

Gotta get back to work. More head stuff later.

[Beer Baron]

great choice of cams mate. and they look excellent. you're right on the price of tomei springs. even the type A's are $$, I have the type B set and that was silly money and the type C is off the planet. I have heard that the supertech springs are excellent too.

[AtomicBomberMan]

BB thats good to hear. I wasnt totally sure on these in the beginning. Its the first time ive really taken American stuff on board. It used to always be Japanese this and Japanese that. At the end of the day, its the $$$$ that do the talking.

[AtomicBomberMan]

hmmm... alright, the cams will be held in by Tomei cam cap stud kit. I was told i needed these if i were intending on revving the engine. I found these to be fairly reasonable as ARP would have been pretty much the same price. No doubt the Tomei ones are made by ARP too.

[AtomicBomberMan]

Valve guides.... so much choice! This is a set of HKS valve guides i bought. These havent been in production for years! Check manufacture date on the box! Anyway I found out the hard way that Japanese valves are all 0.5mm oversize. And VERY hard. If you bash these into your head, it will almost certainly crack it. So these need to be machined down on the outside for fitment. This is according to JHH engineering anyway. More money i didnt intend on spending. The inner part of the guide needed to be reemed (is that the word?) out a little too for the valves to fit. This little excercise cost approx $300 and a set of Supertech guides would have cost about the same! Oh well.... i'll know next time! (if there is a next time)

[scissored sil]

so many things that make me wanna touch myself. hahah. anyway before i get carried away...

hope you guys can see through plastic. as when i dropped it off at the shop, i still hadn't taken it out of the plastic.

From what i have seen of the crank, it is quite nice, i'll try to get another better pic sometime soon.

[AtomicBomberMan]

Thanks Nick, from what we can barely see, it looks good. hahahah just kidding. From what i know, These are a forged crank. they are not full counterweighted ie 8 counterweights instead of 12. Still a very nice crank though. What pistons did you end up choosing for your kit? cooling channel? Please add better pictures when you get them. I'm sure the rest of the members would love to see it!

Edited June 4, 2009 by AtomicBomberMan

[AtomicBomberMan]

Ok, next is valve selection. At one stage, when the dollar was good (remember those days?) the NAPREC (Nagoya Precision) valve system was looking almighty attractive. But being 1.5mm oversize sorta changed my mind. This would require the valve seats to be redone. Extra money i did not wish to spend. I was told that if i were to go 1mm oversize, i would be able to keep the existing seats. By this time the dollar wasnt a pretty sight. The Ferrea valves were very expensive, and any Japanese stuff is definitely out of the question. I had read on the forums somewhere that some hardcore mx-5's were experiencing a lot of problemts with their valvetrain. They had tried many different brands and still ran into problems. As it pans out, someone had tried the supertech products and all of a sudden these were all the rave! After speaking to Will at John HIll Engineering, he confirmed that he had used these before with no problems at all and very good results. I decided I would try these on my car. Pricing was very reasonable too.

The Supertech intake valves were stainless with a black nitride finish.

The Exhaust valves were made from inconnel, a material which handles heat better than stainless and has been used in F1 cars for quite some time.

Side by side

Underneath

Part numbers etc for those that are interested

I missed this pic of the Spring and Retainer specs. Supertech specifies to use the standard spring seats for the dual valve springs. However they did not specify what to use for the inner spring. Luckily Will from JHH made something up with GTiR seats.

Edited June 4, 2009 by AtomicBomberMan

[Roy]

Saynno to Apexi cams, i have tried some in my RB20 and i know of a big dollar bild R33 GTR that ran them and it made it cammy and peaky with a big hole in response

[AtomicBomberMan]

Gosh! Roy! a bit late now! theyre already in! what were the specs of his cams? and his configuration? what do you mean by cammy? it would depend on how the cams were dialed in wouldnt it? and wouldnt tune have a lot to do with it? This is a little too technical for me.