Likely cost of a engine upgrade/rebuild

[IROC-Z]

Hopefully someone on here will humour me!

One of my long, long term plans for my IROC-Z is to have the engine upgraded to either a 5.7 crate engine or a rebuild with performance components. It currently has a 305 TPI. I’d be hoping for an output in the region of 250-300bhp with a fairly mild tune, no choppy idle stuff just a smooth motor. I don’t have the knowledge or facilities to do the work myself so I’d have to pay someone to do everything. For example I’ve seen a company called Autopontiac will upgrade a 305TPI with a 350 crate motor and retain the TPI system, that sounds ideal.

I’m in no financial position to get the work done so I don’t want to pester the various suppliers and waste their time, so hopefully someone in the know here satisfy my curiosity?

How much to be rebuilt with performance components?

How much for a total swap, fully fitted etc?

Thanks in advance

[HD Adam]

Have a look here http://www.britishamericanengines.co.uk/default.as...

[qube_TA]

It's not that hard to do yourself and as it's properly expensive to pay someone to do it (£5K-ish) then I'd do the former.

[MikePCG]

Speaking as a 3 time Camaro owner, as mentioned it's going to be expensive no matter what option you go for when paying someone else to do the work for you. If you can't do the work yourself, your best bet is to get a car that's already had the work done, or sell the Iroc and look out for a 91/92 Z28 with a 240-245bhp 5.7 tpi motor and may be do a few minor bolt ons from there.

Why not look at a 4th gen with a 275-305bhp LT1 motor, although I have to say to to me they do look a little too Japanese sports car like in thier style.

[IROC-Z]

HD Adam said:

Have a look here http://www.britishamericanengines.co.uk/default.as...

Thanks for the link, I've seen these guys before and their prices give a good indication of what I'm getting into! I'm still none the wiser of how much a rebuild would be though

qube_TA said:

It's not that hard to do yourself and as it's properly expensive to pay someone to do it (£5K-ish) then I'd do the former.

It's not so much the difficulty, its the lack of facilities. Call it a confidence thing but it's a job I just wouldn't fancy tackling on my own.

MikePCG said:

Speaking as a 3 time Camaro owner, as mentioned it's going to be expensive no matter what option you go for when paying someone else to do the work for you. If you can't do the work yourself, your best bet is to get a car that's already had the work done, or sell the Iroc and look out for a 91/92 Z28 with a 240-245bhp 5.7 tpi motor and may be do a few minor bolt ons from there.

Why not look at a 4th gen with a 275-305bhp LT1 motor, although I have to say to to me they do look a little too Japanese sports car like in thier style.

I had considered this but I really like my IROC and I've spent quite a lot of money on it so far, I am planning to get the bodywork sorted too. That said for the cost of an engine, I could probably buy another Camaro!

I agree the 4th gens don't really do anything for me, they don't really look American enough.

[chevy-stu]

You could probably get your engine rebuilt with a mild tune, but you're still looking at a few grand, as the cost of crate engines shows.. Also figure into having someone take yours out and put in the new one, plus any other uprated parts like new engine mounts, torque converters etc..

I can't remember for sure but when I had my IROC I was told the standard 5 litre TPI set-up is very restrictive. I'd personally just add a decent exhaust, headers, an intake aerofoil and a powerchip which will liven it up a bit.

You could keep an eye one ebay and buy a decent rebuilt 5.7 engine but it's a chance.

[300bhp/ton]

IROC-Z said:

Hopefully someone on here will humour me!

One of my long, long term plans for my IROC-Z is to have the engine upgraded to either a 5.7 crate engine or a rebuild with performance components. It currently has a 305 TPI. I’d be hoping for an output in the region of 250-300bhp with a fairly mild tune, no choppy idle stuff just a smooth motor. I don’t have the knowledge or facilities to do the work myself so I’d have to pay someone to do everything. For example I’ve seen a company called Autopontiac will upgrade a 305TPI with a 350 crate motor and retain the TPI system, that sounds ideal.

I’m in no financial position to get the work done so I don’t want to pester the various suppliers and waste their time, so hopefully someone in the know here satisfy my curiosity?

How much to be rebuilt with performance components?

How much for a total swap, fully fitted etc?

Thanks in advance

Lots of options and lots of choice.

Personally I'd be tempted to look at a LS1 swap. AQ tad more money, but a much better bet in the long term.

You can buy most of the bits to do it. Its not quite a straight swap, but not bad in terms of engine swaps.

Biggest issue comes from any additional parts you'll need. Such as transmission, brakes, suspension, rear axle and so on. It would probably be cheaper to buy a 4th gen. But if you want to keep the 3rd gen looks that isn't really an option.

[IROC-Z]

Thanks for the feedback guys, I just wanted to get an idea. Looks like the money will be better spent on sorting out the bodywork and alloys for now.

I've been looking at ported intake plenum, runners, manifold base and I'll probably go down the route of maximising the potential of the induction system, at least this is work I can tackle myself and the engine can stay in the car!

[MikePCG]

Looks like your keeping the IROC then. As you have mentioned there's quite a few things you can do with the induction and exhaust and are as usual good places to start.

I can also recommend these books, which I have owned (actually probably still got them somewhere amongst my immense (read messy) library of car books?:

Camaro performance handbook
How to tune and modify your camaro

[300bhp/ton]

If you want to keep it simple and make it drive better then maybe look at changing the final drive ratio, most factory ones are pretty tall, more sporty gears will make it more fun and faster.

If its an auto look to getting a stall, it won't produce any extra HP but it'll make it feel much quicker.

Exhaust tuning is the usual - free flow exhaust system, most are pretty good or get one custom fabbed.

I suspect you could remove any CATs as it should be old enough not too need them.

If you do the headers go for long tubes - any other type of header for n/a use it pretty much a waste. They need to have long primaries to promote exhaust scavenging, that's where the power is.

As for the intake, well I'm sure the factory inlet manifold is not ideal (afraid I don't know much about these motors), but a descent cold air induction kit will at least help. Sure there are plenty for sale or fab something up.

[IROC-Z]

Yep I'm keeping my IROC, I've put quite a lot of effort into sorting out the niggling faults and it's a tidy car. Those books you mentioned I have although they don't give any indication as to how much parts cost.

I've got a flowmaster stainless system on it and the cat has been removed at some point, so I guess I'm ahead there.

Excuse me ignorance but do exhaust headers replace the stock manifold and Y pipe?

Also, what is a stall?!

Thanks

[qube_TA]

300bhp/ton said:

Personally I'd be tempted to look at a LS1 swap. AQ tad more money.

Biggest understatement of the decade!

[MikePCG]

IROC-Z said:

Yep I'm keeping my IROC, I've put quite a lot of effort into sorting out the niggling faults and it's a tidy car. Those books you mentioned I have although they don't give any indication as to how much parts cost.

I've got a flowmaster stainless system on it and the cat has been removed at some point, so I guess I'm ahead there.

Excuse me ignorance but do exhaust headers replace the stock manifold and Y pipe?

Also, what is a stall?!

Thanks

Ok i'll try to explain these?

Manifold/Header:
A manifold basically will have the cylinder outlets go to a single pipe (shared), a header will have them go to a seperate pipe then into either one or two to one pipe, thus reducing back pressure (of course one replaces the other in your question).

Stall (torque converter):
Like a manual cars clutch a torque converter allows the engine to run with the wheels and gears not turning, they also convert the engines torque to the drive (hence the name). These converters can be upgraded to change the multplication of the torque converted, therefore you can change the amount of torque produced. Also a smaller diameter converter will allow for a higher stall speed and therefore put you higher up the powerband for a quicker launch.

Mike

Edited by MikePCG on Saturday 16th May 09:10

Edited by MikePCG on Saturday 16th May 12:34

[heightswitch]

qube_TA said:

300bhp/ton said:

Personally I'd be tempted to look at a LS1 swap. AQ tad more money.

Biggest understatement of the decade!

Yep.

Why would anyone want to remove a perfectly good old Iron lump which produces power and fires up with just 3 wires connected for the complexities of a multi wired, sensored ECU controlled engine to gain nothin really in terms of horsepower I do not now.

car engines today are very reliable but when they do go wrong its a pain to have to plug them into a lap top to find which electronic gismo is no longer working.

Theirs nowt wrong with Old fasioned when it works!

N.

[ss64ii]

Hi
I could either-
Rebuild your existing 305 complete to your spec,
Supply a rebuilt 305 for you to drop in
Supply a rebuilt 350 for you to drop in.

I have 2 305s and various 350s that need going through.I have a full rebuild kit for a 305, loads of 350 parts too, been building them for years.

PM me if you're interested.

[qube_TA]

heightswitch said:

qube_TA said:

300bhp/ton said:

Personally I'd be tempted to look at a LS1 swap. A tad more money.

Biggest understatement of the decade!

Yep.

Why would anyone want to remove a perfectly good old Iron lump which produces power and fires up with just 3 wires connected for the complexities of a multi wired, sensored ECU controlled engine to gain nothin really in terms of horsepower I do not now.

car engines today are very reliable but when they do go wrong its a pain to have to plug them into a lap top to find which electronic gismo is no longer working.

Theirs nowt wrong with Old fasioned when it works!

N.

It's not just that, you'd have to change so many items in order to get the new block to work (plus buying the engine as well) as they're not the same shape as the old ones, in addition as they're so much lighter too, you'd throw all the handling out as they'll have lost the weight at the front and your car is pointing skyward all the time.

Sure they're a much better engine and they have more scope for improvements and fuel efficiency but it's only a dirty 80's muscle car and would not have the resale value to make all the effort worthwhile.

A standard crate engine will drop straight in and 300 horses will be there. You could drop in a tricked up, hot-cammed ZZ4 block with something fancy like a Holley Stealth Ram intake, again for not a fortune and be plenty over 400, however your diff and transmission won't be up to the task, nor will the breaks or chassis be so it will start to become properly expensive and it would still be an old car.

[300bhp/ton]

heightswitch said:

qube_TA said:

300bhp/ton said:

Personally I'd be tempted to look at a LS1 swap. AQ tad more money.

Biggest understatement of the decade!

Yep.

Why would anyone want to remove a perfectly good old Iron lump which produces power and fires up with just 3 wires connected for the complexities of a multi wired, sensored ECU controlled engine to gain nothin really in terms of horsepower I do not now.

car engines today are very reliable but when they do go wrong its a pain to have to plug them into a lap top to find which electronic gismo is no longer working.

Theirs nowt wrong with Old fasioned when it works!

N.

I assume that's a joke

You don't see many 305's making 350hp BTW

[qube_TA]

300bhp/ton said:

heightswitch said:

qube_TA said:

300bhp/ton said:

Personally I'd be tempted to look at a LS1 swap. AQ tad more money.

Biggest understatement of the decade!

Yep.

Why would anyone want to remove a perfectly good old Iron lump which produces power and fires up with just 3 wires connected for the complexities of a multi wired, sensored ECU controlled engine to gain nothin really in terms of horsepower I do not now.

car engines today are very reliable but when they do go wrong its a pain to have to plug them into a lap top to find which electronic gismo is no longer working.

Theirs nowt wrong with Old fasioned when it works!

N.

I assume that's a joke

You don't see many 305's making 350hp BTW

That's only because if you mod a 305 it costs exactly the same as it would to mod a 350, and due to the latter's additional displacement it would produce more power, so it's largely deemed not worth the effort. Other than the displacement the engines are identical.

Purely as an exercise, a stroked 305, properly set up & balanced with some decent flowing heads, proper exhaust manifold, a lively cam and something to feed it properly then 350+ horses would be there, however do the same to the 350 and it would have over 400.

Or you could take your stock 305 and give it some NOS or forced induction, you'd be also there.

check this: http://www.hioutput.com/tech/400hp/400hp.html

and

http://www.thirdgen.org/techboard/tbi/332950-400-h...

Definitely doable if you want to.

[300bhp/ton]

qube_TA said:

300bhp/ton said:

heightswitch said:

qube_TA said:

300bhp/ton said:

Personally I'd be tempted to look at a LS1 swap. AQ tad more money.

Biggest understatement of the decade!

Yep.

Why would anyone want to remove a perfectly good old Iron lump which produces power and fires up with just 3 wires connected for the complexities of a multi wired, sensored ECU controlled engine to gain nothin really in terms of horsepower I do not now.

car engines today are very reliable but when they do go wrong its a pain to have to plug them into a lap top to find which electronic gismo is no longer working.

Theirs nowt wrong with Old fasioned when it works!

N.

I assume that's a joke

You don't see many 305's making 350hp BTW

That's only because if you mod a 305 it costs exactly the same as it would to mod a 350, and due to the latter's additional displacement it would produce more power, so it's largely deemed not worth the effort. Other than the displacement the engines are identical.

Purely as an exercise, a stroked 305, properly set up & balanced with some decent flowing heads, proper exhaust manifold, a lively cam and something to feed it properly then 350+ horses would be there, however do the same to the 350 and it would have over 400.

Or you could take your stock 305 and give it some NOS or forced induction, you'd be also there.

check this: http://www.hioutput.com/tech/400hp/400hp.html

and

http://www.thirdgen.org/techboard/tbi/332950-400-h...

Definitely doable if you want to.

Guess it dpeends what you want. If the car's a keeper an Ls1 will easily make loads more hp and be better on fuel. Plus being lighter should improve handling too. But I agree there is a cost involved. If you're handy with the spanners you can (could??) pick up LS1's complete with ECU for £1500. I suspect a crate 350 making that kind of power would cost more.

Either route has to be good though , just keep the car on the road and performaning I say

Coolio

[qube_TA]

300bhp/ton said:

qube_TA said:

Purely as an exercise, a stroked 305, properly set up & balanced with some decent flowing heads, proper exhaust manifold, a lively cam and something to feed it properly then 350+ horses would be there, however do the same to the 350 and it would have over 400.

Guess it depends what you want. If the car's a keeper an Ls1 will easily make loads more hp and be better on fuel. Plus being lighter should improve handling too. But I agree there is a cost involved. If you're handy with the spanners you can (could??) pick up LS1's complete with ECU for £1500. I suspect a crate 350 making that kind of power would cost more.

Either route has to be good though , just keep the car on the road and performaning I say

Coolio

Not really true though, although I'm not pretending a modern LSx engine isn't far better than a Gen 1 block, but from a horsepower/displacement POV there's little between them. In addition if you go down to the drag strip you're far less likely to find an LSx engine as they're so much more involved to tune and make real power out of as you have all the nonsense with remapping n ECU's.

£1500 is having a laugh, sure you could possibly source an LS1 engine for that money but it wouldn't fit the car without modification to the engine bay, and then it wouldn't match up to your transmission so you'd have to swap that out, you'd also need to swap out the fuel tank and rear axle before it would do anything, the lighter engine would require new springs n shocks up front to keep the car the right height. Also you'd need to convert the engine to a cable driven throttle as the electric one won't work and you'd need to fiddle with the electrics before it would talk to your dials on the dash. This is monumentally more expensive than an engine rebuild on the existing motor, beefing up the transmission and swapping out the fuel pump.

Furthermore if you wander over to the peeps at http://thirdgen.org then quite a few who have done the LSx swap have said that because it's lighter the handling of the car has been worse, yes the 1/4 mile has been better due to reduced weight but it's apparent that GM designed the car with the weight of original engine in mind and changing it throws out the balance of the car.