You can add a DIY ISA Portfolio to your existing InvestEngine SIPP by following the steps below;
My dashboard-> ‘Add new portfolio’-> ‘Create DIY portfolio’-> 'Personal Pension'-> 'Continue'-> select ETF(s)->'Add to portfolio'-> 'Continue'-> Set portfolio weights-> 'Review and continue'->'Save and continue'->Read and agree to the SIPP declaration-> 'Continue'
Once your new DIY SIPP portfolio is available via your dashboard, you can add cash to it by arranging a transfer from your bank account and get investing.
However, if you want to fund your new DIY SIPP portfolio from your existing Managed SIPP Portfolio, you would need to sell down all or part of your holdings in your Managed portfolio. Please note: you must ensure you do not withdraw any cash monies if you have a Managed SIPP portfolio or from your SIPP Account cash; if you do, there could be fees and charges incurred.
Follow the instructions here on how to make internal transfers: Can I transfer funds between my portfolios?