Single Turbo Rover V8 3.5 Triumph TR7 Build

thewedgeshop.com · Post by **thewedgeshop.com** » Fri May 11, 2012 1:56 pm

I have been in the process of building a Single Turbo Rover V8 setup for my 1977 TR7 FHC.

The motor will be a stock rebuilt 3.5 Rover with std compression (8:1) which is ideal for the turbo application. I will be using Cometic head gaskets,in which the heads have been shaved down to accommodate the extra thickness of these gaskets. Erson cams has designed a special grind pattern for the application that will be suited for the turbo application with power from 2500-6500. A Holley 750 blow thru carb from CSU setup specifically for my setup. The Holley will sit on top of a harcourt single plane intake manifold. The setup will be intercooled with 2.5in piping. I will be using rover manifolds that will push a single Garret To4b turbo designed to run efficiently at 10-15lbs of boost

The transmission will be a stock rebuilt Rover trans LT77. The cars already has The Wedge Shop Mustang rear end conversion and all the other goodies.

I will update the thread over time with my progress. I plan on making the turbo setup into a kit in which anyone can bolt on their stock 3.5 with no modification and push 250Hp to the wheels.

P.S. The end goal for this car is to become a GROUP 44 Replica

Here are some more specs on the setup.

Specs on Driving
Street car
1 -5 drag passes a year
Driven to cars shows 600+ miles
6300k Redline
Drive ability is important
300-350WHP Target

Quick specs on Motor:
215 cubic inch
Aluminum Block
Aluminum Heads
Fresh rebuild
ARP hardware
Cometic Headgaskets
Makes 210hp in NA form

Specs
Rover 3.5 (215 cu in)
8:1 compression
93 Pump Gas
ARP head studs, main studs
Stock Heads
Erson TQ20 on a 112 (478 lift, 214 duration at .050)
Cast pistons, rods
Single plane intake
Blow thru Carb (Holley 650)
10-15psi max
Mallory 6 Box (Boost timing retard functionality run off MAP sensor 1* timing pulled per 1LB of boost)
Intercooler Core Size 11"X12"X3" Overall Size 18"x12"x3" 2.5" Inlet & Outlet 3" Core
3 in Mandrel bent exhaust from Downpipe back
160* thermostat
Mallory SS distributor 24* advance with 10* static advance
1 PTE 46mm External Wastegate
1 Tial 50mm BOV
Garret to4e 60 trim .58 A/R O Trim T4 exhaust housing with 3in Vband outlet

The transmission will be a stock rebuilt Rover trans LT77. The cars already has The Wedge Shop Mustang rear end conversion and all the other goodies.

I have acquired most of the parts for the build expect a few major things like the turbo, front timing cover, rad supports and all the intercooler and exhaust plumbing.

I will update the thread over time with my progress. I plan on making the turbo setup into a kit in which anyone can bolt on their stock 3.5 with no modification and push 250Hp to the wheels.

P.S. The end goal for this car is to become a GROUP 44 Replica

Thanks
Clint

ChrisJC · Post by **ChrisJC** » Mon May 14, 2012 7:37 am

Very good. Keep us posted please.

Chris.

stevieturbo · Post by **stevieturbo** » Mon May 14, 2012 10:31 am

Looks like a tight squeeze, but nice work.

What size is the carburettor ? it will need to be pretty small to work given it's a single plane manifold.

I tried a 600DP on a 3.9 then 4.6 twin turbo and even then it was always too big, with flat spots on opening the secondaries. Even with the biggest pump circuit I could use.
Initially for a few years just ran using the primary side only.

then eventually I modified it into a 465 DP, although even then it was still a little large

I'd say a 390 DP if one could be made would be ideal.

mgbv8 · Post by **mgbv8** » Mon May 14, 2012 7:53 pm

Looking good Clint !!

From the engine pics I would make 2 suggestions. First see if you can drill and tap a small 1/4" plug in top of the thermostat housing. It makes final top up easy. I have fitted one in mine. We fill via top hose until water runs out of the housing. Then top up via the small hole with mineral water bottle with a 3mm hole drilled in the cap??

Secondly those rocker covers. A friend of mine bought those 2 years back for his MGB V8. I had just finished a rebuilt top to bottom and it was a sweet balanced engine.
He fitted those himself. He brought the car back after 500 miles with very low oil pressure. When I drained and strained the oil there was a lot of very fine black particles in the sump. The particles were hard and jet black.
This had me confused until I took the rocker covers off and cleaned the inside witha rag. Same black particles on the rag?? And the inside surface of the rocker covers was a very rough cast finish. It was casting sand I guess??

It had got everywhere and stripped a lot of metal from bearing surfaces.

So after another full rebuild + crank polish, new can and lifters etc it was ok. But not after about 10 hours scrubbing, jet washing and power brushing that crap out of the inside of the rocker covers.

FYI!!

Might be worth checking Clint..

Regards
Perry

chodjinn · Post by **chodjinn** » Tue May 15, 2012 1:02 pm

Impressive, to a point ... all that work and expense, and you are using stock rover heads?! That's just silly. It's well know the most restrictive part of any RV8 is the heads, and pound-for-pound (or dollar-for-dollar) modifying the heads is a) the best and b) the cheapest (comparatively) for gaining power from you RV8 engine, no matter what the state of tune.

I really don't understand why you've kept them stock, unless it's for race classification?

stevieturbo · Post by **stevieturbo** » Wed May 16, 2012 11:47 am

chodjinn wrote:Impressive, to a point ... all that work and expense, and you are using stock rover heads?! That's just silly. It's well know the most restrictive part of any RV8 is the heads, and pound-for-pound (or dollar-for-dollar) modifying the heads is a) the best and b) the cheapest (comparatively) for gaining power from you RV8 engine, no matter what the state of tune.

I really don't understand why you've kept them stock, unless it's for race classification?

With boost you can prioritise other areas where the money will be better spent.

ie, you'll get far more from from spending the money on a turbocharger setup than you ever will modifying cylinder heads.

It's very simple. So say you've £1500 to spend. It makes a hell of a lot more sense to ignore the heads and fit the turbocharger with that money. ( although I would reccommend upgrading valve springs at least.

chodjinn · Post by **chodjinn** » Wed May 16, 2012 1:20 pm

I know what you're saying Stevie, but having gone to all that length of a complete rebuild, why not improve the heads since the most gains can be had there? You ran stage 4 heads on your RV8 twin turbo, and I'm sure you didn't spend all that money for fun!

I mean, he's paying for a custom camshaft when an off-the-shelf high torque one would do a similar job. I could say the same thing about the expensive harcourt manifold and tial bov. I wasn't criticising, I just would have done it differently. Besides, you should probably just ignore me I'm no longer a V8 owner lol.

kiwicar · Post by **kiwicar** » Wed May 16, 2012 2:35 pm

Personally I think the combination of a 650 4 barrel carb on a single plane manifold and a 3.5 litre engine will be the most challenging bit of this set up. I think it will take alot of setting up, there will be nearly as much throttle plate area as piston area presented to each port what the booster jets will make of that I don't know. Through standard ports?

I think throttle responce will probably be "interesting" to say the least especially with only 8:1 CR. . . . I would have thought even a 390 would have been on the large side, especially with a turbo

It all seems a bit of a miss-match of components as pointed out above.
Best regards
Mike

thewedgeshop.com · Post by **thewedgeshop.com** » Wed May 16, 2012 3:57 pm

All,

Thanks for the replies. To answer a few questions.

Thanks for the heads up on the valve covers. We have run these on almost all our cars with no issues, but I will still give a look at the ones on my car now.

The Carb is a 750 from www.csucarbs.com. The carb was specifically setup for a turbo system on my motor. They use all your specs including head flow, cam and compression numbers to set it up for you. I have heard nothing but good things surrounding the company.

I agree the heads are not ideal for this setup, but the plan was to see what could be accomplished with a fairly stock 3.5 Rover V8 to get a baseline. Once I have this and get the engine running strong, I can always change the heads and go to a better setup. Also for cost reasons it was easier to just stick with the stock heads and the 3.5.

The car should be up and running in the next few weekends. I will keep you guys posted.

Thanks
Clint

stevieturbo · Post by **stevieturbo** » Wed May 16, 2012 6:06 pm

Obviously the company has experience with turbo carbs....but I'm still sceptical, even more so because of the single plane intake.

As for heads again. You can say "Why not" for many things.

Why not a bigger engine, why not better heads, why not better turbo, why not etc etc

Although I do agree the intake is probably not the best for the job either, especially when matched to that huge carb.

A huge carb and intake would be geared towards high rpm and big power. Neither of which a basic 3.5 will ever do. So you should be seeking to use the intake/carb etc to promote low rpm power and let the turbo takeover at higher rpm's

mgbv8 · Post by **mgbv8** » Wed May 16, 2012 7:53 pm

Another issue I would expect with the single plane mani is the front cylinders of the engine leaning out when racing. I have to put up with this on mine. Its not uncommon but it does need to be taken into account when tuning for racing with hard acceleration for sustained periods.

Its all down to budget really I guess.

This happens with or without boost when you stick a big carb on an open inlet manifold. It still happens on dual plane mani's but to a lesser extent.

I tune mine on the front plugs to make sure I have my safe mix up front for drag racing. I will soon be able to remove this issue when I fit my direct port nitrous injection kit. I will then be able to jet and tune fuel and nitrous to each cylinder.

This would be the formula I use for sizing a carb on your engine.

215 ci X 6000 max rpm / 3456 = 373.26 cfm.

Add in the boost factor. 1 bar is atmospheric pressure so 7psi of boost = 1.5 bar total pressure.

373.26 cfm x 1.5 = 559.89 cfm required from carb.

For 15 psi, call it 1 bar of boost you would need….

373.26 cfm x 2 = 746.52 carb cfm required

So the carb sizing is ok in my book for a drag race application where we dont really bother about part throttle use. I tune mine on the dyno at wide open throttle only and this has been fine for me

stevieturbo · Post by **stevieturbo** » Wed May 16, 2012 9:04 pm

Ran mine for years blowing thru a carb and single plane. Never had any issues with mixture distribution. It is not a concern.

thewedgeshop.com · Post by **thewedgeshop.com** » Wed May 16, 2012 9:24 pm

I appreciate all the input and am very excited to see how the car does react given the components installed.

I realize that the manifold and carb are meant for high end power, but in talking to some industry experts they stated using the single plane was the only way to go and a dual plane intake would have serious adverse effects.

The car should be up and running in the next few weekends and I am not trying to build a pure drag race car or horsepower king. I will be driving the car on the street, to car shows and long road trips. I am ok with a slightly laggy low end, but in the calculations I did, I am expecting to see around 7psi at 2000rpms and full boost 10-12psi by 3000rpms. Those are only computer simulations though and I tend to air on the side of real world results!

Thanks
Clint

kiwicar · Post by **kiwicar** » Thu May 17, 2012 9:04 am

mgbv8 wrote:Another issue I would expect with the single plane mani is the front cylinders of the engine leaning out when racing. I have to put up with this on mine. Its not uncommon but it does need to be taken into account when tuning for racing with hard acceleration for sustained periods.

Its all down to budget really I guess.

This happens with or without boost when you stick a big carb on an open inlet manifold. It still happens on dual plane mani's but to a lesser extent.

I tune mine on the front plugs to make sure I have my safe mix up front for drag racing. I will soon be able to remove this issue when I fit my direct port nitrous injection kit. I will then be able to jet and tune fuel and nitrous to each cylinder.

This would be the formula I use for sizing a carb on your engine.

215 ci X 6000 max rpm / 3456 = 373.26 cfm.

Add in the boost factor. 1 bar is atmospheric pressure so 7psi of boost = 1.5 bar total pressure.

373.26 cfm x 1.5 = 559.89 cfm required from carb.

For 15 psi, call it 1 bar of boost you would need….

373.26 cfm x 2 = 746.52 carb cfm required

So the carb sizing is ok in my book for a drag race application where we dont really bother about part throttle use. I tune mine on the dyno at wide open throttle only and this has been fine for me

Interesting, not how I would calculate it on a blow through set up. May be suck through but not blow through

Best regards
Mike

stevieturbo · Post by **stevieturbo** » Thu May 17, 2012 11:22 am

thewedgeshop.com wrote:I appreciate all the input and am very excited to see how the car does react given the components installed.

I realize that the manifold and carb are meant for high end power, but in talking to some industry experts they stated using the single plane was the only way to go and a dual plane intake would have serious adverse effects.

The car should be up and running in the next few weekends and I am not trying to build a pure drag race car or horsepower king. I will be driving the car on the street, to car shows and long road trips. I am ok with a slightly laggy low end, but in the calculations I did, I am expecting to see around 7psi at 2000rpms and full boost 10-12psi by 3000rpms. Those are only computer simulations though and I tend to air on the side of real world results!

Thanks
Clint

And I will also add. That while I did use the single plane for years. I also later switched to a 360 Offy manifold, again largely due to the carburettor complications in that the single plane plus an oversized carb just made tuning very difficult. Airspeed dropped so much during transients it almost always bogged down.
This place that specialises in turbo carbs may have solutions, I could never find one with the 600, hence I ended up just using the primaries only.

I ended up with the Offy manifold and my DIY 465 DP Holley made from bits from the 600DP and a 465 vac sec carb.
Driveability and performance was improved everywhere.

Then I ditched it and went efi lol