well I am a little happier tonight to discover that there are NO cracks in my pistons .... I have removed both heads for inspection only to find that the lines that I could see through the plug holes were in fact carbon lines that cleaned off easily . NO CRACKS !! yey .... and the heads appear to be sealing really well .
however I did find a gremlin in No-4 inlet guide has moved , guide boss has broken & valve seat moved in the head .... this explains the very low compression pressure on this cylinder .
A few minor head repairs and back together next week , refit my air-water intercooler & cold air intake pipe , then a dyno session prior to the Sydney Jamboree
A little nitrous jet will also do wonders for the intake temperature and the gain in HP is bigger than the actual jet size.
2443TT wrote:Have you considered runing a water/meth system with nozzles both pre and post turbo? I run two 150cc pre turbo and a 300cc post intercooler setup on my skyline. The effects are pretty impressive.
On a hot day of 38 degrees when stuck in traffic it is not uncommon to see a heat soaked temp of 60 degress at the intake. Get on boost and with the water/meth operating, it immediatly knocks 15 to 20 degrees out of the air temps post intercooler. I am sure that it is actually more than this too, because the air temp sensor is slow to react and I don't ever get to see the temp drop curve stabilise at a lowerst value before having to get off the throttle.
Another benefit was being about to run 26lb boost with 25 degrees of ignition with 12.8:1 AFR's while maintaining EGT's below 830 degrees. The knock monitoring system records noise values lower than I used to see with just pump fuel and much less boost.
If I had to guess, its probably a combination of your air temps and your elevated EGT's and combustion chamber temps that are causing your detonation issues at the top end of the track. Ive seen this on methanol burning v8's too. There is a point in the top end of the rev range when under max load where they have to drown the engine in fuel to keep EGT's down. Ive always felt that even a tiny bit of water injection post turbo would do wonders for these methanol burners by eliminating the hot spots in the combustion chambers.
hypo-vwAustralias 1st 10sec street beetle (Jan 2007) 10.49secs@132m
inlet guides on no-3 & no-4 cylinders have been replaced . I had to ream guides to accept chevy valves . Valve seats have been recut , valves have been refaced and the heads are on the milling machine to reface the chambers . In my previous post I made a comment that the heads appear to be sealing OK , however they were not . The heads had got so hot that the headshims that I had manufactured had impacted into the head surface and this was not visible until I removed the shims when doing repairs .
I now realise that the noises in the engine I could hear was not detonation , but the heads lifting under high boost pressure
my son Dean helps me fit up the air-water intercooler , water pump , reservoir and hoses . I fill the system with water to discover that the intercooler has an internal leak and water is entering the air chamber .
The system is drained and out it all comes and the boost pressure will be lowered to run this saturday . This will assist in keeping air intake temps lower
Bad luck with the intercooler, is that a PWR unit?
Steve
Hi Steve , no it is not a PWR intercooler mate . If you check back through the earlier posts on this thread you will see that I took an air-air intercooler and had tanks made for it to convert it to an air-water intercooler .
Last time I used this intercooler I did have trouble with water getting into the intake as you can see in this vid
, I removed it and had it tested . Apparently it was repaired and OK 👎
tonight I started back on my heads and it all turned pear-shaped early ..... while refacing my Pauter heads a large hole appeared on the barrel seating surface of No-2 cylinder . It appears that the heads have been welded in the past and a large air-bubble in the alloy has broken open . Ben Ford rushes the head to a local engineers shop ( that works similar hours to me ) and has the head rewelded while I start to manufacture adaptor plates for my pushrod tubes . I have had issues trying to keep the pushrod tubes sealed at the cylinder head as the heads do not have a taper in them for the seals to locate . There is not enough material in the heads to machine the taper so I will make bolt-on adaptors
Wayne out of curiousity what rods are you running? Looking at lightweight stroker rods from pauter but they only do 3/8 rods bolts for type 1 big ends. I was going to go with 5/16 but if that is all they do then I guess they will have to do. Waiting on a price but have been told they are roughly $300 cheaper than Cunningham stroker rods. By running these I will have more clearance to cam lobes so hence bigger profile on cam which would be nice!! Slowly getting parts accumulated to get this thing happening!!
Looking forward to hearing your dyno results now you've found the gremlins robbing you hp!!
ACCEPT THAT SOME DAYS YOU ARE THE PIDGEON AND SOME DAYS YOU ARE THE STATUE
took several incar vids at WSID drags . Unfortunately the microphone level was too low and couldnt here the sound . Ben Ford has just rectified / amplified the sound on the vids as we sit here at Valla Beach Resort for the VW Spectacular. I have just uploaded 1 onto youtube .....
Sounds like an early shift into 4th, maybe some more in it?
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hypo-vwAustralias 1st 10sec street beetle (Jan 2007) 10.49secs@132m
Took the oval to the dyno several weeks ago for a tune prior to warwick. All was going really well until I got greedy with the boost. As the boost approached 26psi, number 1 top headstud stripped causing a case failure as the other headstuds could not support the load. We have known for a while that this is the weaklink in the type-4 engine and work is already underway to strengthen a new case.
Always pushing the limits Wayne!! So will you have something ready for Warwick? As far as strengthening the case around those top studs welding up the case in that hollow and perhaps a brace across the top of the case to the studs on the other side like a cradle?
ACCEPT THAT SOME DAYS YOU ARE THE PIDGEON AND SOME DAYS YOU ARE THE STATUE
after a lot of thought & homework over the past 12 months regarding the type-4 engine in the oval , I have decided to fabricate an external chomoly cradle that will wrap the entire type-4 engine block . This cradle will be 15mm thick at the cylinder mounting faces , will be dowelled & supported via 8 custom fabricated main bearing bolts ( 6 in the factory locations & 2 across the top of the case )
The main bearing bolts will be 14mm in diameter and the 24 cylinder head studs ( 6 per cylinder ) will screw into the chromoly plate , not the alloy case .
I have had to get Pauter to custom make a new set of modular X-beam rods for me 6.1" long . The rods that are currently in the old engine are 5.5" long . The rods have arrived this week , the Raceware headstuds have arrived , and I have been collecting a few other goodies
Pauter have also made me 2x sets of semi-modular cylinders for my engine , but are waiting on me to give them dimensions for final machining
I have purchased a new set of custom light-weight disc brakes for the rear of the oval & a RLR rev-6 dual disc clutch assembly to suit the type-4 engine
Hey Wayne,
Wow I would never have believed that if I hadn't seen it. The idea you have is brilliant but will expansion of the block cause you any problem ( possibly bearing clearance) . I was looking at your pictures and rereading your post , would a deck plate held together by your main ( larger) case bolts and head studs that also tied the plate to the case do the same thing ? I know whatever you come up with be well thought out and It will be something well worth reading about . Mike McCarthy
hypo-vwAustralias 1st 10sec street beetle (Jan 2007) 10.49secs@132m
dragvw2180 wrote:Hey Wayne,
Wow I would never have believed that if I hadn't seen it. The idea you have is brilliant but will expansion of the block cause you any problem ( possibly bearing clearance) . I was looking at your pictures and rereading your post , would a deck plate held together by your main ( larger) case bolts and head studs that also tied the plate to the case do the same thing ? I know whatever you come up with be well thought out and It will be something well worth reading about . Mike McCarthy
Hi Mike , what you have described is what I am doing mate , I may have worded it differently than you do thou . My cradle is an external cradle which consists of 2 case deck plates retained by the 6 custom main bearing bolts , joined across the top of the case to form a cradle with 2 extra main bearing bolts . This will not expand the case or have any adverse effects on engine bearings or clearances . This will just make the cylinders sit 15mm further off the case making the engine approx. 30mm wider ( hence the reason for the 6.1" rods ) . All of the headstuds will be threaded 10x1.5mm directly into the chromoly deck plate , lining up with the original 12mm stud holes but not actually threading into the case . Wayne
Timing the threads between the plate and the case would have been a challenge without going to a bigger stud or using a " timesert " and locking the plate to the case half perminately bonding them together. I look forward to seeing your project. Mike McCarthy
Like your car and build. l also think this strengthening is a good move.
Steel plates were pretty common late 70´s and in to 80´s in Sweden prior to alloy cases and the Pauter arrived.
I have also seen a TIV with thick aluminium plates in a thread build from US.
This is my hybrid engine from the 70´s that later was modified with steel plates 1990 when I took the engine to turbo and the street.
Do not know why the URL directlink does not show the pictures? Links work though.
hypo-vwAustralias 1st 10sec street beetle (Jan 2007) 10.49secs@132m
