Hi I’m building a 56 oval up for next years Ampol re-run trial and am planing to run in the modified under 1500cc class. Has any one got an idea on
how to build a hot 1500. What heads, piston, rods, crank to run.
Eg
1600 heads and piston with a 1200 crank or 1500 pistons with 1300 twin port heads and 69mm crank.
Any one done this before?
will be running a 1500 gearbox.
using 64mm stroke with 85.5 bore gives 1470cc, 64x87 gives 1522cc there is still a lot more info needed to determine you style of engine ..eg carb allowences.rod length cam choice.....where do you want the motor to work...botttom end?....is it a touring event or are there rally sections used...the re-run of the redex was a let down and it really consisted of a drive..thats my opinion.are you able to forward more info on this event including the organizers..have a interest as a possible entrant..what's the entry fee? thanks steve
the event is a 4 week 10000 km roas trial with special speed sections (hill climbs and sprints). as for the carbs I have all the standard vw carbs plus a pair of 40IDF and a few sets of progresives. In the cams I have stock to full drag. I only have stock rods but am looking at after market one. I'm planning on using a new Aluminium case as I don't have any good standard cases. I also have a 69mm counterweighted that I can use. So I guess I just want to see what other people have used.
From what i remember Guy_H targa car ran a de stroked 1600, mad into a 1300. that way he still had th strength of the 1600 case etc. But from what i understand its a really hard to drive, and needs to be kept above 4k otherwise it will mis behave.
Do you wish to do build the engine yourself? Are you restricted by engine block rulings etc? New 1500 bore kits are rare - do you have a good standard
set of P&Cs? My thoughts: Twin port heads, baby cam, Kadrons and pipes around a 1500 case should do the trick. Maybe a counterweight crank if you need
a few revs for some stages and have lowish gears. If you have alloy case, great - but it really is overkill. Whatever you do, you DO NOT want a
big-carb engine that needs 4000rpm to come on-song!!
If you can find one, you should use an early 70s 1300 twinport gearbox for under 1640cc for performance. I had a Pobjoy 1640cc in a 1300TP swing-axle
car years ago and it pulled well from down low - essential for road-style competition/touring events - and was almost as quick to 100kays as my
taller-geared Kadron-fed 1916cc. You need what I had but with 141 less CCs!nn[ Edited on 4-8-2005 by VWCOOL ]nn[ Edited on 4-8-2005 by VWCOOL ]
The event is run by the Peugeot car club of VIC. The same people that ran the redex. I think the it costs $2600.
The event is call the "Round Australia Trial Rerun 50th Anniversary 23rd april to 21st may.
I would build what Guy Harding did only use a smaller camshaft duration.
IE offset ground 1200 crank and 1600 barrels( 87s might work with 1500cc limit).
I think he used choked down 40IDFs and 40 x 35.5 dual ports.
ok now know the style of event..barry fergerson ran the redex with a 1776 76 bug ..it ran an 110 engle with stk valves and flywheel..8.0:1 compression and a single downdraft webber..a very reliable unit as this engine also ran the playstation round australia event with a oil change and a tappet reset 14'000ks round trip!...your aim would need to be long legged....use a 3.87 final drive with 15 in wheels to try and keep the rpm down at high speed as the sections are LOOOONG. a counterweight 69 with stk 1500barrel and piston 83mm...,stk valves with a good flow head work and a engle 100 may produce a good 65hp-70hp with a set of smaller twin carbs...stk doghouse cooler with a full flow and remote thermostat operated cooler will also be of great benefit..try and keep compression to 7.5:1 as fuel gradeswill not always be a choice, remember its a long drive sacrifice a little hp for reliability ...on the 56 shell also cut out the rain deflectors behind the grill intake as you will need all the air you can suck..hope this gives some food for thought cheers steve ps mathew berry built guy's engine for the record.
thanks for the suggestions. Better to learn from other than to break down half way. Will start look for a set of 1500 pistons and barrels. Do twin port 1600 head fit 1500 barrels? Or do you need to mod. 1300 tp heads?