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Top Swap - Getting ready to start - questions and advice first by qwikgta
Started on: 09-06-2021 05:13 PM
Replies: 8 (221 views)
Last post by: qwikgta on 09-20-2021 04:00 PM
qwikgta
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Report this Post09-06-2021 05:13 PM Click Here to See the Profile for qwikgtaClick Here to Email qwikgtaSend a Private Message to qwikgtaEdit/Delete MessageReply w/QuoteDirect Link to This Post
Before you tell me not to do it, or why bother, I've already got all the parts and a box of new sensors, gaskets, bolts and bits.

The base motor is a 04 NA and I've gotten the heads and Supercharger off a 06 GT. I've read the threads here and on the GP forums and I just want to ask for those who have done it, what did you do right and/or wrong. What should I watch out for and would you have done something different.

From what I can tell, the only difference in the wire harness is the wire for the boost control solenoid control circuit. I know it will need a re-tune from the base NA to the 06 SC and I'm planning on getting Ryan to reflash the PCM.

I plan to keep the motor in the car, and one of the things I can't seem to find out is, if its possible to remove and replace the harmonic balancer while the motor is in the car? Has anyone done or tried this?

also, if I'm not having any issues with the lifters, would you suggest replacing them at this time? Finally, if i'm replacing the rocker arms, valve springs, retainers and keepers do I have to keep the valves in the same holes? I plan to clean them and lap them before installing the springs, but do I need to keep them in the same location as when i pulled them out?

Thanks in advance

Rob
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fieroguru
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Report this Post09-06-2021 07:03 PM Click Here to See the Profile for fieroguruSend a Private Message to fieroguruEdit/Delete MessageReply w/QuoteDirect Link to This Post
You can remove the rear cradle bolts, loosen the front cradle bolts and tilt the cradle back to lower the balancer below the frame rail. Not sure if it is needed for the 3800, but it is one of those easy things to get more clearance in certain areas of the engine bay for maintenance work.
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Dennis LaGrua
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Report this Post09-07-2021 09:48 AM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
The 3800SC top swap has been done many times before and it can work. Just remember that the N/A motor has a 9:1 compression ratio, uses different rods, and pistons. You will have to run the 3800SC PCM program and use a 2 bar MAP sensor and this may translate into running less boost and doing some adjustments to the timing tables in the PCM program. An intercooler would probably help. ZZ performance has been selling the top swap kits and is a good source for information.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

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Blacktree
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Report this Post09-07-2021 01:35 PM Click Here to See the Profile for BlacktreeClick Here to visit Blacktree's HomePageClick Here to Email BlacktreeSend a Private Message to BlacktreeEdit/Delete MessageReply w/QuoteDirect Link to This Post
For the higher compression, you can back off the spark timing a bit and/or use higher octane fuel.

Regarding the valvetrain, it's usually recommended to keep the valves where they came from, unless you're doing a valve job.

[This message has been edited by Blacktree (edited 09-07-2021).]

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cmechmann
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Report this Post09-10-2021 07:14 PM Click Here to See the Profile for cmechmannClick Here to Email cmechmannSend a Private Message to cmechmannEdit/Delete MessageReply w/QuoteDirect Link to This Post
3800na in stock form and with non boosted mods can take severe beating. With a top swap it starts to get a little dicey. You will be tuning a lot and you are always going to want more. Pushing a little too far and things go south even without you knowing it.

[This message has been edited by cmechmann (edited 09-10-2021).]

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Dennis LaGrua
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Report this Post09-10-2021 10:13 PM Click Here to See the Profile for Dennis LaGruaClick Here to Email Dennis LaGruaSend a Private Message to Dennis LaGruaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by cmechmann:

3800na in stock form and with non boosted mods can take severe beating. With a top swap it starts to get a little dicey. You will be tuning a lot and you are always going to want more. Pushing a little too far and things go south even without you knowing it.

Rob will also need the larger SC injectors and will need to be diligent about monitoring the A/F ratios and the KR's. Run lean or with too much boost and the engine goes away. The SC engine already requires 93 octane gas, but with the SC on NA setup water injection or intercooling might be needed to prevent detonation. For tech advise I would call Zoomer at ZZ performance for recommendations on the top swap.

------------------
" THE BLACK PARALYZER" -87GT 3800SC Series III engine, custom ZZP /Frozen Boost Intercooler setup, 3.4" Pulley, Northstar TB, LS1 MAF, 3" Spintech/Hedman Exhaust, P-log Manifold, Autolite 104's, MSD wires, Custom CAI, 4T65eHD w. custom axles, Champion Radiator, S10 Brake Booster, HP Tuners VCM Suite.
"THE COLUSSUS"
87GT - ALL OUT 3.4L Turbocharged engine, Garrett Hybrid Turbo, MSD ign., modified TH125H
" ON THE LOOSE WITHOUT THE JUICE "

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reinhart
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Report this Post09-12-2021 04:22 AM Click Here to See the Profile for reinhartClick Here to Email reinhartSend a Private Message to reinhartEdit/Delete MessageReply w/QuoteDirect Link to This Post
Putting boost on an engine that wasn't designed for boost is always a gamble. If it were me I'd consider beefing up the lower end: con rods, maybe pistons. Also with the high compression ratio, you're going to have to turn the boost way down from the SC version.
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CSM842M4
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Report this Post09-15-2021 08:40 AM Click Here to See the Profile for CSM842M4Click Here to Email CSM842M4Send a Private Message to CSM842M4Edit/Delete MessageReply w/QuoteDirect Link to This Post
I'm with blacktree on keeping the valves in their original locations. The only time I would deviate from this rule of thumb is if ALL the valve stems miked identically all the way up AND all the guides were in spec and not more than a few thousandths between loosest and tightest (or are replacing as necessary), AND you were having all the valve faces and seats ground (like 'tree said, valve job). Once a valve have spent any serious time working against one seat, through one guide, the three should be considered married. My $0.02 worth, take it for what it cost you! Let us know how everything goes - Chris
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qwikgta
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Report this Post09-20-2021 04:00 PM Click Here to See the Profile for qwikgtaClick Here to Email qwikgtaSend a Private Message to qwikgtaEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by CSM842M4:

I'm with blacktree on keeping the valves in their original locations. The only time I would deviate from this rule of thumb is if ALL the valve stems miked identically all the way up AND all the guides were in spec and not more than a few thousandths between loosest and tightest (or are replacing as necessary), AND you were having all the valve faces and seats ground (like 'tree said, valve job). Once a valve have spent any serious time working against one seat, through one guide, the three should be considered married. My $0.02 worth, take it for what it cost you! Let us know how everything goes - Chris


but doesn't this also assume i'll get the valves back in, in the same orientation? if not, then the valve face will be contacting a different location on the seat and the rocker will be touching a different location on the tip. so why be worried that its the same valve in the same location?

My plan is to strip the heads myself and then bring them in for a good cleaning and I need one of the rocker holes drilled/tapped b/c of a broke rocker stud. After cleaning I was thinking I would lap the valves myself and install them w/ new guides, spring, seats and keepers. I also have new rocker arms and lifters. I plan to buy new pushrods too, but I have to make sure i get the correct length so I have a pushrods measuring tool and once I determine the size i'll get new ones. I'm assuming the valves are all straight and that I wont have to buy new ones.

now with all that, I am not sure if I should install the new lifters, b/c I don't know if there is anything wrong with the ones I have. I would not have done the springs and rockers if I didn't find damage, so I need to replace them. Got new keepers and seats w/ the springs and new guides are cheap so it made sense. if the motor was running fine and there is no damage to the valves and rockerarms can they be reused or is just a good idea to go with new. and what are the odds i'll need some other size pushrods, shouldn't I just measure the ones I have and go with that size? What would change thier length? I'm going with the stock cam and stock lifters.

Thank for any input. i've done 5-6 swaps, but I've never gotten into the motor before other than bolt on stuff like headers, intakes ect.

Rob
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