76 deg cam in l28

[Riceburner]

I want to fit a Wade 76 degree cam into my L28 is there anyway of telling if the valves will hit the pistons? It's a p90 head and f54 block with flat top pistons, wade said cam lift is 344 on the lobe and 521 at the valve???

[luvemfast]

What lift on the cam and what type of pistons? dished or flat tops?

But even then, I couldn't tell you 

[Riceburner]

According to Stuart Wilkins there will be plenty of clearance! Yay 

[luvemfast]

What kind of engine are you building Gareth?

Ø89mm pistons

76° cam

God knows what else, as these will need to be matched or its a waste of time and money.

Speaking of which, better check the money tree in my yard to see if it's flowering yet

 

[Riceburner]

Had a change of plan after chatting with Peter. First, I'll get him to work the head and do the 76cam at the same time, then build a bottom end slowly with 87.5 or 88mm pistons and some other goodies 

[Zedman240®]

Hope you don't want to drive it on the road too much...it's going to be a real pig! especially with carbs!

[C.A.R.]

Peter is a mad man, but it'll go hard Gareth!

[Riceburner]

hehe More Power!! Is 76 going to be an undriveable beast below 3500rpm? 

[peter mc]

hi p90 has higher roof 3 mm or so no need for piston mods  76 hi lift work great in my combo

[Riceburner]

Thanks Pete    I notice the 74deg works rally is very close to the 76, is that useable too? Also will this work on my bottom end until I can build up the overbored block?

[peter mc]

yes p90 head  will bolt on . l28 comp will be low but i weld chambers to rectify or build piston to suit

[peter mc]

yes 74 and 76 hi lift are both very similar in hp i like both i have been trying 79 from japan it likes to rev. made power to 9200 but very hard to drive 4.4 diff and cr gear box made it ok .race only  76 all so likes diff gears and comp 10.5 .1 min to work the head must flow well into the 600 th Regine if you wont good results

[Riceburner]

So the wade 74 sounds a bit better suited to my L28, provided I get your wizard work on the ports and weld up chambers?

 

Also are Kameari valve springs ok for this?  they are rated to 9000rpm, spring length 40-41mm, cam lift 8-9mm.....

[peter mc]

i have a set in the shed and sum coswerth springs  they are both rated to 16 mm .  76 hi lift is 580th valve lift or there abouts

[luvemfast]

76 hi lift is 580th valve lift or there abouts

This is best suited for a race motor isn't it?

Be a pig on the road I would assume.

But, on the track would knock your socks off 

[PZG302]

In my experience the 76 cam has worked very well in a couple of motors i've used, the first in a L28 with standard EFI system, wasn't the big pig I thought it would be, but assumed that the injection helped smooth out the power delivery. Car pulled from about 4000 to 7000 with peak power at 6800. That was using a P90 head.

 

You would more likely find the cam too big for the road with carbies than injection, and the 74 or even dropping to a 72 degree cam may be a better option for a car that sees most of its use on the road. I have had a stanza that was running twin webbers and a 76 degree cam and it was undriveable in the wet and felt like a two stroke it was that peaky in the power delivery.

 

In the current spec, L28 block with N42 head and Haltech F9 computer in the 240, we found with the porting work done for more torque than power the 76 cam felt a bit "fluffy" and didn't really work. I now use a 74degree cam which suited my engine much better, power and torque was made in a similar rev range. With the new bottom end and tweak to the head we are making plenty of torque and power with the 74 degree cam, but not sure if the 76 degree cam would be of benefit as the motor has been built for more torque than outright power as I believe that torque is more useful on the track or in a hill climb.

[260Coupe]

Gareth

 

Some background info from the engine dyno tests I have had done on my own engines and witnessed on many others run up on the Power Play engine dyno.

 

 

Firstly-  big cam does not automatically translate to big HP......cams generally move peak HP further up the rev range and it is a complex combination of engine specs that produce HP rather than cams........(and remember what you gain up top you generally loose from down low with a big cam)

In most L28s with big cams , the sudden big shove in the back at 4500 rpm that feels like it making huge power is more often attrributed to the big hole in the power and torque at low RPM rather than massive HP gain.  (I proved this myself on the dyno with my engine build )

FYI

I have seen Les Collins engine dyno many L28s and gone from a 70 to a 76 deg cams with very little peak HP difference (my L26 was a similar story) , the same was found with many Stewart Wilkins engines........it seems more power can be gained from head porting, induction and exhaust rather than cam shafts.

 

Anyway my 2c

 

 

 

[GV260]

Couldn't agree anymore with Alan's comments. Spot on.

 

Hey Peter, I presume your User photo is my old 260Z. When are we going to see some photos of the "new" beast? Do you still have the old roll cage? Apologies for stealing this thread!

[Riceburner]

I have decided to go for the 74 works rally grind in combination with Peter doing some special headwork on the standard P90. According to the specs I think the 74 should come on around 3500 and go to7500, its road reg but is hardly driven on the road.

 

Thanks guys I do really appreciate all the info and advice, has helped a lot 

[Zedman240®]

Are you going to get Wade to make it? I think they know it as a "568A" grind. IIRC

[Riceburner]

Yep, I belive thats the 74 works rally grind 

[peter mc]

cam is not so good when head is shi... when used on l28 with comp. exh  it comes in to it own 

[peter mc]

ps ask sw about the last dyno sheet i sent him . made more power than any other l28 that he has seen

[peter mc]

.......................is 200 hp at 4000 rpm enough torque for you and max power at 6500  and flat all the way 8000

[luvemfast]

.......................is 200 hp at 4000 rpm enough torque for you and max power at 6500  and flat all the way 8000

Sounds very nice, how much money does an engine like that cost?