Rebuilding a Race Engine

[tim]

Hi Ross, I am just starting to buy parts for a RCR GT40. I have looked at a engine package close to yours. When I sit down and add up costs it becomes quite expensive with Block, Heads, Trottle bodies etc... Then to find a good engine builder to build it right the first time. At the moment I am considering buying a DJR Supercar engine compete less motec. The parts are very expensive to buy out right but as a used engine they seem a bargin.

Tim

 

[tim]

Harrop SVO manifold

 

[Ross Nicol]

Hi Tim
That manifold is a very nice piece of work. This may help you, I puchased the race motor for $12,000, supposedly half of it's original cost, about 4 years ago. Even though I've lost the short motor the heads, camshaft, dry sump and pump, and 4 barrel Motec manifold leave me with quite a bit of value.
I would be concerned purchasing an ex race engine. As in my case I doubt the cracks in the block were caused by me running the bearings, which means they were most likely there when I purchased it. If I ever purchase an engine fully built again I would strip it to check for cracks and clearances etc before handing the money over. So in Summary if you buy new, at least you know what you've got, however I'm still crack testing my new parts before assembly.
Now a question arises, would a V8 Supercar engine be a good thing for a GT40? Well my answer would run down these lines -

1/ Maybe in a race car but not a street car.
2/ Gearing! Remember the V8 Supercars are fitted with very close ratio Holinger gear boxes and our cars are not, unless you've shelled out megabucks for a Hewland (Lain Pretty)
3/ These close ratios allow the 302 engine to be peaked for HP at the expense of torque.
4/ High rev engines need more teardowns due to wear

So to sum up a fair amount of research needs to go into your decision, not just the financial one.
I've made my! decision, I know what I've got, I've chosen a 347 stroke to develop power at lower revs and to provide the torque that overcomes (to some extent) wide spaced gear ratios
A lot of Falcon owners have fitted 347 stroke engines for street use. I suppose there's nothing like torque for laying rubber. Have you considered a crate motor? Pretty cost effective and absolutely brand new.

Cheers
Ross:thumbsup:

 

[Ross Nicol]

I've just found my piece of cardboard I wrote the block weights down on.

Block from standard 302 HO mid 80's engine - 56kg/112lb approx
(front main bearing missing)

Ford Racing B50 302 block 4 bolt mains fitted to 2,3,4.- 62kg/124lb

Dart Sportsman block as supplied 4bolt mains 2,3,4 - 84.5kg/169lb
( part# 31354175)

As you can see my new Dart block is heavier than the other 2 but it is also very strong and a proper race block.

Ross:thumbsup:

 

[Jac Mac]

Ross, I dont agree with your thoughts regarding super car engines. IIRC these are rev limited to 7400 and the in car camera often shows RPM down in the 4k region so they dont lack torque either, not the lightest of cars and they do standing starts plus when things get marginal on fuel or tire they seem to be able to short shift etc with little real effect on lap times. They are also only 305 cu in @ 3.00" stroke so maybe you should reconsider your crankshaft choice...say 3.250" stroke, nothing I havent suggested already

 

[Ross Nicol]

Ok Jac Mac I'll get some numbers from Scott Owen he has built quite a few Supercar engines and would have dyno figures no doubt. What is your opinion on high wear rate on an engine that needs to rev to 7000 as opposed to 6000 for it's power? If I hadn't spent $600 on balancing the 3.4 crank I would most likely have taken your advice on the 3.25 unit. I understand that if my 347 goes badly and I have to make changes, you will no doubt come down on me with a ton of bricks. Hey by the way can you tell me if my new Dart block will still need oil restriction, considering it has priority oiling to the mains. The B50 had a restrictor behind one of the rear gallery plugs. My mob are racing this weekend at Sandown and it's the first meeting i've missed for a long time. A guy from our club has a Cobra with a stroked 351 ( Claims it's only 6 Litres) did a 1min 14.8sec lap yesterday. Considering the record is 1min 13.6 set by a Dodge Viper, that's pretty good, he beat the Lambo. Not bad for a home made Ford eh!

Ross:thumbsup:

 

[tim]

Hi Ross, points taken. The reason I am looking at a supercar engine is mainly for the parts supplied with the engine. I also no that DJR racing as not cut corners in building and developing this engine. I'll post some spec's and photo's of the engine on monday, as there is limited information on these engines. All I no is basically 600hp @ 7500rpm 10:1 compression. I think this is overkill for a GT40 considering its power to weight. Should be able to detune the engine. If interested the motor cost $25,000AU, the Harrop SVO manifold sells for $14,000AU. I beleive the engines are $100,000 new.

I have asked Craig to source a Ricardo box from Fran, this is what I intend to use.

Any one with information on the Supercar V8 engine?

 

[Ross Nicol]

Tim
I'd be concerned with the block used in a Supercar, they hack into it to lighten as much as they can. Only problem with that is it most likely reduces it's strength. They don't care of course because they replace on a regular basis. However you and I would want it to last as long as possible. If they cost 100k why sell for 25k? maybe they are worn out. If your after the internals, well they have probably had a hard life too. I'm too cynical to think these motors haven't been buzzed a few times, remember the young drivers are hot shots that don't own the cars. I wouldn't go near one, too risky, but I'm well known to be miserly. Of course I could weld up those cracks in my old block and assemble a motor for sale, but could I live with myself if I didn't tell the new owner? No!
You say parts supplied with the engine so you may mean external parts which would be good if you got value for money.

Ross:thumbsup:

 

[Jac Mac]

Ross, with regard to the priority oiling on the Dart Block I do run a restrictor/s in the fwd position that is in the order of 0.180" dia ( contrary to some builders I prefer a lot of oil top end for valve spring cooling ) and since this is dry sump flow requirements can be adjusted with pump speed. The Dart oil gallery layout & flow while initially looking similar is totally different from the Ford B50 where you can restrict all lifter gallery oil with the one restrictor at rear right just above the main gallery. Make sure your builder gets a handle on this!
With the 3.4" stroke you have I would want to do a teardown each off season, with a 3.250" or shorter stroke I would probably extend this out to every second or even third season assuming that there was no metal in filter cuts or problems in the valvetrain and leakdown tests. That is an indication of how much the 3.400" stroke & its rod ratio tend to alter the wear/breakage factor particularly in piston skirt & bore. This is on the assumption that you would be using a 7500/7600 RPM limit on the motor.( Are you trying to tell me that you are going to use a hyd roller & 6000 rpm only for this build )
BTW, the filter cut/leakdown/visual spring check should be for each meeting that you do simply as an insurance thing.

 

[tim]

Hi Ross, I agree that these motors are not new. The value to me is mainly the external parts like the intake manifold, dry sump system, CNC heads,roller rockers etc. They seem to be high quality items with a good service life. I expect the engine to need to be freshed up. It was a 888 race engine from 2006. As for the block is it a SVO race block modified???
There are some bargins out there at the moment because of the R word. I am seeing this when I buy trucks, around 40% less than 18 months ago.

 

[Ross Nicol]

Jac Mac
I may have given you the wrong impression, I'm having the machining done by the experts but intend to complete the assembly myself. I will have my tolerances double checked though. This means I will have to fit or have fitted,the required oil restrictors, hence my question about this. I purchased a template to notch the lower bores myself but the Dart block has these notches as new. I will be checking they are ok though. I would like to follow your principles as to oiling, clearances and any other advice you can give me. The block is off being crack tested at the moment so I haven't started any work on it yet. Could you give me the exact detail on how to make and fit the restrictors please. Your suggestions on yearly teardown and maintanence checks are great as I have been unaware of what I should be carrying out and at what intervals. I'd like to have this in detail when the build is complete. I intend to use the roller cam that was in the B50 which has solid lifters and I'm thinking 7000 rpm will be my upper limit.
Cheers Mate
Ross:thumbsup:

 

[BruceA]

Hi Ross, points taken. The reason I am looking at a supercar engine is mainly for the parts supplied with the engine. I also no that DJR racing as not cut corners in building and developing this engine. I'll post some spec's and photo's of the engine on monday, as there is limited information on these engines. All I no is basically 600hp @ 7500rpm 10:1 compression. I think this is overkill for a GT40 considering its power to weight. Should be able to detune the engine. If interested the motor cost $25,000AU, the Harrop SVO manifold sells for $14,000AU. I beleive the engines are $100,000 new.

I have asked Craig to source a Ricardo box from Fran, this is what I intend to use.

Any one with information on the Supercar V8 engine?

It has always amazed or amused me as to the prices some people tend to charge or value on an engine. At $100kAUD I would want titanium everythings and a years free petrol as well. I cannot see how you can spend that much money on an engine, as parts are not that expensive. I guess the builder has to make a huge profit somehow. In my opinion, what I see is only a perceived value for the uninitiated.

 

[tim]

I agree Bruce, I would not pay $100,000 for an engine. I cry when I repace my truck engine at $35,000. It is 600hp, but at least I get 1 million km service life and warranty. The used DJR engine is expensive for some at $25000 but do you sums. Here is a challenge can the guys on the forum price a motor with a decent 4 bolt block, crank, alloy heads, roller rockers, roller cam etc... With 8 barrel injection with injectors, ram tubes, then add a dry sump system with pump, brackets and braided lines. Then add to this machining costs, assembly, tuning. Would love to see what the guys come up with. Bottom line will it be close to a proven 600hp using a 10:1 compression ratio.

 

[Maurice Butler]

Just poped back to the thread to see if anything was happening all gone quiet

 

[Jack]

I agree Bruce, I would not pay $100,000 for an engine. I cry when I repace my truck engine at $35,000. It is 600hp, but at least I get 1 million km service life and warranty. The used DJR engine is expensive for some at $25000 but do you sums. Here is a challenge can the guys on the forum price a motor with a decent 4 bolt block, crank, alloy heads, roller rockers, roller cam etc... With 8 barrel injection with injectors, ram tubes, then add a dry sump system with pump, brackets and braided lines. Then add to this machining costs, assembly, tuning. Would love to see what the guys come up with. Bottom line will it be close to a proven 600hp using a 10:1 compression ratio.

At risk of personal injury, the GM LS7 engine with a mild cam (crate engine) fulfills all of this for under 14K.

 

[czan]

At risk of personal injury, the GM LS7 engine with a mild cam (crate engine) fulfills all of this for under 14K.

Custom GM LS7 Engine - 730 HP Gen IV Small-Block - Car Craft Magazine

730 hp at 7400rpm

 

[Red9]

At risk of personal injury, the GM LS7 engine with a mild cam (crate engine) fulfills all of this for under 14K.

And last how long as a track engine? To make race ready cost plenty-- the same as any engine .

 

[Rick]

You can purchase a used 358 CID Sprint Cup engine less manifolding form Jack Roush for about $16000 US that make excess of 800HP. It will have the best internals available, and be set up for dry sump. These are engines that run at the front of the pack.

 

[BruceA]

And last how long as a track engine? To make race ready cost plenty-- the same as any engine .

I cannot recall what the race was, but I was watching some stuff on YouTube about production car races, and the new Z06 was competing in the races. It was done on virtually a stock engine and was holding its own amoungst the Ferrari and Porkers in the same races. They had no engine trouble but I recall a driveline issue. Its a good engine with stuff like Titanium rods etc already from the factory.

 

[Keith]

I cannot recall what the race was, but I was watching some stuff on YouTube about production car races, and the new Z06 was competing in the races. It was done on virtually a stock engine and was holding its own amoungst the Ferrari and Porkers in the same races. They had no engine trouble but I recall a driveline issue. Its a good engine with stuff like Titanium rods etc already from the factory.

Ah! But........

Sorry 'bout the thread drift Ross