a olsson Posted September 18, 2007 Share Posted September 18, 2007 Under going 1900 SCHolar bottom end rebuild Is it worth porting the head whilst it is in bits ? Is it worth upgrading cams ? If so is it best to fit 1227 or 1444 aiming to use 8000rpm max Is there any other tricks worth including ? any advise appreciated Thanks Link to comment Share on other sites More sharing options...
CageyH Posted September 18, 2007 Share Posted September 18, 2007 It would be a shame not to port the head after spending all that money on a 1.9k bottom end. Only dead fish go with the flow....! Link to comment Share on other sites More sharing options...
Andy Best Posted September 18, 2007 Share Posted September 18, 2007 I have just done the Scholar VHPD upgrade but kept mine 1800cc. I would say it is worth porting the head, balancing the internals (if you are planning going to 8000rpm)and fitting some verniers. I stayed with the existing VHPD cams as funds ran out, following the visit to Emerald last weekend I am really pleased with the result really usable torque and great to drive on the road. I guess you need to ask what you want from your engine to decide which cams to use. If you are stopping at 8000rpm I suspect that the two cams above are probably a bit too hot as you will loose out lower down the rev range, though someone will probably tell me I am wrong in a minute. I used oily for the engine assembly and porting and vibration free for the balancing, I really questioned the benefits of balancing the engine but I am really glad I kept the existing cams and put the money into that piece of work. Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted September 18, 2007 Leadership Team Share Posted September 18, 2007 Adrian, whilst myself and Andy were at Emerald we discussed something much the same as you're planning with Dave Walker - my engine is a 1900K running 1444 cams and although an incredibly smooth unit and a barnstormer at high revs (244bhp at 8000rpm), I don't feel that the engine makes the most of the mid-range tractability that could be had with a change of cam. Dave mentioned that he's planning to build a 1900K, fully ported big valve, but running a cam such as the vhpd or 285 to make the most of mid-range torque and longevity. IMHO this spec would be about the best you could choose for a road going/occasionally tracked K-Series 7. Stu. www.superse7ens.co.uk..........the rebuild 😬 Link to comment Share on other sites More sharing options...
rj Posted September 18, 2007 Share Posted September 18, 2007 Stu, What is the spec of your head? Curious as I'm going 1.8 max port / valve soon and may go for 1444 cams. /regin Link to comment Share on other sites More sharing options...
Support Team Shaun_E Posted September 18, 2007 Support Team Share Posted September 18, 2007 My 1900K has a VVC head (VVC mech removed) fully ported by Dave Andrews and uses Piper BP285H cams. With Jenvey DTHTBs and an Emerald ECU it produced 227bhp and 167lbft on Emerald's rollers. Have a look at the power plot here. It makes a brilliant road engine - easier to drive than the Supersport it started life as. It will trickle around town when required yet provides effortless overtaking and is also ample on track. I had the bottom end balanced by Vibration Free. The pistons are forged (by Pistal), the rods are single tang but otherwise standard and the crank is standard. Peak power is around 7800-8000rpm so I have limited the revs to 7800. Yellow SL #32 - member of Drowned Rat Racing Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted September 18, 2007 Leadership Team Share Posted September 18, 2007 Regin - DVA fully ported with 32.5mm inlets, 28.3mm exhausts. All the work was done by the first owner of the car - I'm the 3rd and just benefitting from it 😬 Stu. www.superse7ens.co.uk..........the rebuild 😬 Link to comment Share on other sites More sharing options...
a olsson Posted September 18, 2007 Author Share Posted September 18, 2007 Thanks for the views it seems I may be better to port the head rather than change the cams.I was balancing the vhpd crank and bottom end and using Arrow rods with the omega pistons which give the 1900cc. Land Rover head gasket Verniers and an Emerald ecu Do the 1227 and 1444 cams only give more above 8000 rpm ?? Link to comment Share on other sites More sharing options...
rj Posted September 19, 2007 Share Posted September 19, 2007 Thanks Stu. Just curious as I'm going 33.5 / 28.7 (Off the top of my head) /regin Adrian, you don't really want an engine that peaks above the rev limiter. In the current disguise my own engine peaks at the limiter resulting in me always hitting it. Problem will soon be solved, but... Most annoying at present. Link to comment Share on other sites More sharing options...
mav Posted September 19, 2007 Share Posted September 19, 2007 RJ, I seem to remember when V7 had the work done, etreme care had to be taken wiht the cam timing when using vlaves this big and the 1444 as ther ewas potential for the vlavles to 'lock' against each other, clearance was that tight. I'm sure Oily will be along to clarify... Link to comment Share on other sites More sharing options...
oilyhands Posted September 19, 2007 Share Posted September 19, 2007 Both lift at TDC (timing) and valve pocket size are an issue when you go above 31.5/27.3mm, with extreme valve sizes it is perfectly possible for the valves to hit each other when simply turning the cam over in the head so be careful. V7 didnt enlarge the pockets in his pistons and the valves just kissed the sides of the pockets bending every single valve enough for them to leak, fortunately the contact wasnt heavy enough to break the vae heads off although fatigue would have done this in time. Oily Link to comment Share on other sites More sharing options...
Mick Day Posted September 19, 2007 Share Posted September 19, 2007 Shaun Interesting result. My spec from DVA is almost identical, except my TB's are on a manifold & it uses a GEMS ECU. The 2 Steve's got 227BHP & 164ft/lbs out of it. Agree with you on the drivability. When taking friends for a ride they're really impressed with the acceleration. Even more so when I tell them it's rare to change out of 6th!. Mick Link to comment Share on other sites More sharing options...
rj Posted September 19, 2007 Share Posted September 19, 2007 Mav and Oily, Thanks for the warning. I intend to do a dummy build, and will soon start making a 3d drawing in SolidWorks of the head / piston /crankshaft assembly to clarify that I have sufficient space. I'll also offer up an old set of pistons, which are currently on conrods with marking blue and probably some sort of gum to the valves to check. But... Thank you very much, can never be too careful. I am on thin ice, but I want to prove to myself that I can do it. If I'm too full of myself then it's going to be an interesting POOOOF! 😳 Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted September 20, 2007 Leadership Team Share Posted September 20, 2007 Whilst we're on the subject then, what's the concensus over going to steel rods in a 1900K? I currently have the 1900 in the car (the original V7 engine, "standard" vhpd single tank rods with Pistal pistons), but I also have another vhpd engine in bits. This was Steve Butts' old Elise engine - 1800 vhpd with Arrow rods and fully floating Omega pistons. It's tempting to give the 1900 a refresh over the winter and utilise the AP rods, returning the 1800 vhpd unit back to, er, just that, with the single tang rods. I'm not sure whether the Pistal pistons are fully floating though and whether the rods would be a straight swap? Anyone enlighten me on this one? I think Oily actually built both Stu. www.superse7ens.co.uk..........the rebuild 😬 Link to comment Share on other sites More sharing options...
oilyhands Posted September 20, 2007 Share Posted September 20, 2007 They should both be fully floating. Standard rods are pretty tough. Oily Link to comment Share on other sites More sharing options...
Leadership Team SLR No.77 Posted September 20, 2007 Leadership Team Share Posted September 20, 2007 So it's do-able but questionable whether it's worth the trouble! Stu. www.superse7ens.co.uk..........the rebuild 😬 Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now