|26/01/2005 00:08:27||Max||Hi fellows,
does anyone have an idea where to get stiffer valve springs for a V4 from?? I got now almost everything ready to the next step in engine improvement, the only thing missing are these springs... I hope someone knows about them.
|26/01/2005 07:52:11||Richard||Ford V6 springs are stiffer and I use them in all my rally engines, use v6 retainers and collets too. Not hard or expensive to get. Burtons in the UK stock them. Check the valves do not bottom on the oil seals if using a high lift cam. You may need to shim under the valve springs slightly.|
|26/01/2005 15:56:03||Max||@71sonett: are the v4 springs of the P7 really stiffer than the original Saab ones or did you mean v6 ones? Have you also used stiffer retainers?
@Richard: Do you mean these Ford V6 springs that have been used in P7?
|26/01/2005 18:29:11||Max||Well let's see... I planned to use max 6000-6500 rpm as I use the car as my everyday driver. I think I'm going to put in these V6 springs together with the lightened lifters and someday a lightened flywheel. By the way: Is it neccessary to balance the flywheel after milling it to the dimensions listed in the Saab Sport and Rally papers from the 70ies?
|27/01/2005 06:52:56||71 Sonett||@ max: the original P7 items are the same as the ones used in our V4's. But they offer also the stiffer springs.|
|27/01/2005 08:08:14||Richard||Yes it needs to be balanced. Only go to the first step for lightening the flywheel, dont bother with the one that only has the tags for the clutch plate for road use.
What timing gear are you using, these need to be steel if you want them to last more than a year. The later nylon gears will be ok.
Also you will need to change the cam, a Saab 7.6 will suit your rev range, but will loose a bit of torque below 2000rpm, otherwise a 7.2 will rev to 6000rpm and be a bit more drivable and suit std size valves. The 7.6 lift is ideal for the big valves.
On to oil, Burtons sell a upgrated oil pump for the v6 which fits and increases the pressure.
To use 6500 and have some power there, you will need to port the heads and use a good exhaust.
Make sure the rockers have no wear on the rocker shaft, and you may need to replace these after a few years as the higher revs wear them.
On to gaskets, use RENIZ head gaskets and limit compression ratio to 10:1, the limit for this and the pistons is 10.5:1.
|27/01/2005 12:12:11||Alistair||You can also get a Kent "road/rally" cam with a profile sort of between the Saab 7.2 and the 7.6, works OK with standard top end, and the SAH cam had similar lift to the 7.2 but I believe slightly different timing - would happily rev (still pulling well!) to just over 6100 with stiffer springs but otherwise standard top end HW & lightly skimmed heads (~9.5:1 CR).
Cam timing on the SAH approx:
Inlet open @ 32 BTDC
Inlet close @ 65ABDC
Exh Open @ 65BBDC
Exh Close @ 15ATDC
Rich - do you know how the Saab cams compare?
I already got the Saab 7.2 cam in. Also a Simons exhaust, steel timing gears are fitted. The only thing that limits the power to dyno tested 90-95 hp(I tested it in last yers autumn) now is the rpms and the only slightly done portting of the heads. I already use a compression ratio of a little above 10:1. The engine is now driven max. 40tkm.
|27/01/2005 12:40:44||Richard||Next step is to port the heads, watch the inlet port walls as they are thin. The exhaust can be opened up to suit the exhaust. After that get some rally headers and through the floor exhaust, I used the 'canon'silencer from a 900T and a performance Saab 9000 150mm rear box on its end. With a bit of cutting and welding and some straight pipe it all goes together and you have a quiet exhaust system that does not restrict the power.|
I have some data for the Saab cams and Kent somewhere. The Saab cams are the best, the 7.6 is ace in a big valved big engine car. It pulls from a good 1000rpm lower than the kent equivalent with the same results higher up the rev range.
So what do I build next Al?
|27/01/2005 16:21:22||Alistair||Well... I was just putting some info on saabcensored.com about the 96 turbo that Mike Woolfe & Barry Marsden built about 20 years ago - you could have a crack at summat like that, or possibly an injected V4 using old DCOEs as throttle bodies???
Have you experienced the Saab 8.3 cam? I understand this one is VERY peaky but delivers a lot at the top end? Not so good for rallying but OK on the track I guess.
|28/01/2005 08:13:00||Richard||The 8.3 I think would suit the more revy 1500cc engine. Just looked at the central site, Pers Rallycross v4 produced 200bhp+ with supercharger. The car ended up in the UK with Barry Palmer and the engine was taken out of the car by someone else and the car was used for rallying. I tracked the supercharger down and it had all the fittings from Pers car with it, but the guy Threw it on the scrap heap!!! He did not realise what he had! Bugger....|
|28/01/2005 10:40:24||Richard||Mr Al, I recon I can get above 130bhp from a short throw crank engine (1500cc)using period parts and 8000rpm. Dont tempt me! The team turboed the v4 to test the set up for the 99T. I have a picture of a green rallycross car from the Saab international with a turbo V4, your pistons need to be forged and a strong bottom end is needed.|
|28/01/2005 16:58:51||Alistair||You really think you can get over 130 with a 1500 crank? I thought the limit, even on DCOEs with 8.3 was about 125. Mind you, it wouldn't be as driveable as that turbo was - or as fast, as you wouldn't have the torque...is that a gauntlet I see before me?!
I have seen a similar picture of the V4 rallycross car, also had Lucas FI I think. Didn't they also use 94mm pistons to get it up to about 2 litre?
Mike & Barry's turbo had the bottom end shot peened & tuftrided but otherwise standard HW was used I think. Dunno if it lasted like that mind you, not seen the car for a good 15 years.
Know what you mean about that Eklund engine - our old car was originally built with an ex-Eklund rally engine - 1815, similar spec to yours, but that had disappeared long before we got hold of it :-( and I had to make do with a mere 90bhp. Probably a bloody good thing too, given that I was driving it when I was 18!
|31/01/2005 08:14:05||Richard||The saab data is for single port heads and 7.6 cam. Try twin ports 11:1 and 8.3 cam. The 1500 will rev to 8000rpm with the correct bits and prep. Also the Saab twin port exhaust has too short primary tubes, so more gain here. I would look into having some 1600cc forged pistons made specially for the job. Why, class C2 upto 1600cc. There is no way a big engine Saab can compete against the 1974 spec Escort, Saab had packed up with the 96 and was moving to the faster 99. The 99 is only faster because it handles better, its more stable (naff over jumps). the 99 2ltr engine is worse than the V4, 175bhp is about all you can get which is probably why Saab Turboed it. The 8 port head limits it, its a poor design which a Turbo overcomes.
On top of that, I would be able to use a close ratio sp2 box and 6.35 c & p with the extra revs, so get some more useful ratios.
|31/01/2005 17:51:33||Max||quote from Rich: "...2.8 Cologne V6 engine, which is the ones fitted to to most German Fords..."
What is the situation like in a 2.3l HC V6 from Germany? Are the valve springs also stiffer? What is the situation in oil pump spring?
|31/01/2005 20:19:34||Alistair||Rich - fair enough mate, I hadn't thought about twin port heads etc. WRT the 99, they did get about 225 bhp from the 16v engine before the homologation rules changed but it was still way down on a BDA...
There was a 99 16v head & bits on eBay a while back, wonder what became of it?!
|31/01/2005 22:53:03||Max||..are the V6 2.3l also stiffer? See qestion above.
|01/02/2005 08:17:01||Richard||I think Chris P has a blank head. Thats the reason why they did a 16 valve, the 8 valve head is poor.
Max I always use 2.8 but I am sure all the German v6 (two ports per head not three) are listed as being the same. The springs I use do not have a prgressive coil at one end like the Saab ones.
Burtons sell an uprated (kent?) oil pump for the German V6. See the link above and have a look at their stuff. Otherwise you can work out how much stiffer the spring needs to be from the original as it is only a pressure release valve. It just needs to open at a higher pressure. You will need to then have a spring made.
|01/02/2005 08:18:59||Richard||Its not that far off a 1700cc BDA. A rwd car looses more power in its drive train than a FWD.|