I am thinking of upgrading to a dual Empi 40 Down draft carburetors setup on my 74 1800. The company selling this setup says it's all that I need and to save my money, but I also have heard that this setup is useless without chaging my cams, and just changing the carbs will only add noise.
Should I also look into high compression pistions, or is the stock setup on my 1800 good enough? Does it make sense to upgrade the exchast as well?
I would like to build a setup that is quick, resonably reliable, and not extremely expensive. It would be nice to get some advice from someone that doesn't stand to profit by selling me something. Any insights that anyone can provide would be grealy appreciated.
Performance Myths
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E Prod Racer
Dave,
If you decide to break into the engine to rebuild, you need to do everything to make sure the results work as a whole.
The stock cams are very mild, and should be upgraded to complement the IDFs. Pistons should be 9.8s, and the bore should be fresh, so over bore for available oversize. Prepare the crank, use good bearings, replace the oil pump. Freshen the head. Use a good gasket set.
PM me or post here, to discuss further. I build these engines, and can help you source the parts and services you need to get the job done. I could sell you something, but for my shop, I won't, unless you give me the job of a full build for your engine, which is all or nothing. Sourcing the parts or services, is something I will do for free, through this forum, or by PM.
If you decide to break into the engine to rebuild, you need to do everything to make sure the results work as a whole.
The stock cams are very mild, and should be upgraded to complement the IDFs. Pistons should be 9.8s, and the bore should be fresh, so over bore for available oversize. Prepare the crank, use good bearings, replace the oil pump. Freshen the head. Use a good gasket set.
PM me or post here, to discuss further. I build these engines, and can help you source the parts and services you need to get the job done. I could sell you something, but for my shop, I won't, unless you give me the job of a full build for your engine, which is all or nothing. Sourcing the parts or services, is something I will do for free, through this forum, or by PM.
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dstone
Thaks for the prompt reply, and sorry for my many questions.
One thing to note is that this engine was rebuilt 3 years and about 5,000K ago. However, I did not have performance in mind at this time. This would make to bore fairly fresh, or it is a possibility that they could have just honed out the block. This would also mean that all of the crank bearing were replaced, as well as the oil pump.
Given these would i notice a significant difference in power with the stock pistons? the manual I have states that these are 9.8's already, is that correct?
By freshening the head do you mean having it face sanded again. I have taken an engine rebuilding class a could of years ago, but it is not as fresh in my mind as I would like.
For what I have mentioned above, and what I can take for your email can I assume that I would be in good shape with a new set of cams, gasket set, and a set of carbs, perhaps even an upgraded exhast down the road.
Can you tell me how much a good set of cams will run me? I am pretty sure I can change these myself. Where would I get the shims/etc. to correctly setup the cams when I put them in? I assume that I should also replace the cam bearing while I am at it!
I greatly apprecite the info.
One thing to note is that this engine was rebuilt 3 years and about 5,000K ago. However, I did not have performance in mind at this time. This would make to bore fairly fresh, or it is a possibility that they could have just honed out the block. This would also mean that all of the crank bearing were replaced, as well as the oil pump.
Given these would i notice a significant difference in power with the stock pistons? the manual I have states that these are 9.8's already, is that correct?
By freshening the head do you mean having it face sanded again. I have taken an engine rebuilding class a could of years ago, but it is not as fresh in my mind as I would like.
For what I have mentioned above, and what I can take for your email can I assume that I would be in good shape with a new set of cams, gasket set, and a set of carbs, perhaps even an upgraded exhast down the road.
Can you tell me how much a good set of cams will run me? I am pretty sure I can change these myself. Where would I get the shims/etc. to correctly setup the cams when I put them in? I assume that I should also replace the cam bearing while I am at it!
I greatly apprecite the info.
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E Prod Racer
Dave,
Late reply - very sorry. Most manuals for the Spiders are foreign publications, and don't have the correct specs for the North American engines, which had lower compression (8.1 to 8.9 to 1) flat-top pistons. If you used new pistons, try to remember if they had any kind of dome to them. If they did, they were probably 9.8s.
If the engine was rebuilt 5000 miles ago, and runs well, don't break into it again - unless you are hankering for a project, or want to upgrade to higher compression pistons (if you actually don't have them now).
Check out cams at International Auto Parts, or Vick's, or post a "parts wanted" on any of the FIAT forums.
Find a private FIAT service specialist (don't know where you live, but here in Denver there are two), or order the shims you need from the above vendors, or you can call me at 303-841-1176. I have about 20 pounds of FIAT valve shims! There are no cam bearings in a FIAT TC engine.
Get a good aftermarket exhaust, and consider the system available from Mark Allison - the best available from any source.
Late reply - very sorry. Most manuals for the Spiders are foreign publications, and don't have the correct specs for the North American engines, which had lower compression (8.1 to 8.9 to 1) flat-top pistons. If you used new pistons, try to remember if they had any kind of dome to them. If they did, they were probably 9.8s.
If the engine was rebuilt 5000 miles ago, and runs well, don't break into it again - unless you are hankering for a project, or want to upgrade to higher compression pistons (if you actually don't have them now).
Check out cams at International Auto Parts, or Vick's, or post a "parts wanted" on any of the FIAT forums.
Find a private FIAT service specialist (don't know where you live, but here in Denver there are two), or order the shims you need from the above vendors, or you can call me at 303-841-1176. I have about 20 pounds of FIAT valve shims! There are no cam bearings in a FIAT TC engine.
Get a good aftermarket exhaust, and consider the system available from Mark Allison - the best available from any source.